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List of Freshwater Fishes reported from Brazil
n = 3661
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Table 1: 3624 species currently present in the country/island (endemic, native, introduced, reintroduced);
Table 2: 20 species possibly present in the country/island (stray, questionable);
Table 3: 17 species demonstrated to be absent in the country/island (extirpated, not established, misidentification, error).
Table 4: 3661 species reported from the country/island altogether.
Table : 3661 .
     
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Family Species Author Info Occurrence Common names Abundance Max length Maturity Remark Photo
Anostomidae Abramites hypselonotus (Günther, 1868) Fr, Fi native  Piau-tambaqui (Portuguese), Abramites (Portuguese), Cará (Portuguese), Piau-pedra (Portuguese), Sardinha cará (Portuguese)   14.00 cm TL male/unsexed  Museum: Rio Amazonas, MNHN 99-180 and 181 (Ref. 9743); recored from tributaries of Rio Jurúa (MZUSP No. 50281, Ref. 42843) and also from Rio Tocantins. + 
Loricariidae Acanthicus adonis Isbrücker & Nijssen, 1988 Fr native  Acary avion (English)  20.60 cm SL male/unsexed  Known from Rio Tocantins near Cametá, Pará (Ref. 6868). Also Ref. 36713. + 
Loricariidae Acanthicus hystrix Spix & Agassiz, 1829 Fr native  Canana capeta (Portuguese), Cascudo espinho (Portuguese)   53.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36713). + 
Aspredinidae Acanthobunocephalus scruggsi Carvalho & Reis, 2020 Fr native   2.21 cm SL male/unsexed  Type locality from Acanthobunocephalus scruggsi from Igarape Caipirinha, tributary of Lago Ayapua, Beruri, Amazonas, Brazil, INPA 57946. - 
Doradidae Acanthodoras cataphractus (Linnaeus, 1758) Fr native  Daqueiro (Portuguese), Bacu (Portuguese), Bacu pedra (Portuguese), Baiacu (Portuguese), Botoado (Portuguese), Rebeca (Portuguese), Vacu (Portuguese)   11.50 cm SL male/unsexed  Recorded from Machado river basin (Ref. 97589). + 
Doradidae Acanthodoras depressus (Steindachner, 1881) Fr native   8.10 cm SL male/unsexed  Known from Amazon and Negro River basins (Ref. 37054). + 
Doradidae Acanthodoras spinosissimus (Eigenmann & Eigenmann, 1888) Fr native  Bacuzinho roncador (Portuguese), Bagrinho roncador (Portuguese), Peixe gato (Portuguese), Peixe sapo (Portuguese)   13.70 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Trichomycteridae Acanthopoma annectens Lütken, 1892 Fr native    12.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39970). - 
Cichlidae Acarichthys heckelii (Müller & Troschel, 1849) Fr, Fi native  Acará (Portuguese)   19.50 cm SL male/unsexed    + 
Cichlidae Acaronia nassa (Heckel, 1840) Fr, Fi native  Acará boca de quguiá (Portuguese)   16.00 cm SL male/unsexed  Known from the Amazon Basin. Also Ref. 4537, 36377. + 
Cichlidae Acaronia vultuosa Kullander, 1989 Fr native   12.20 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 36377). + 
Heptapteridae Acentronichthys fissipinnis (Miranda Ribeiro, 1911) Fr endemic   6.00 cm TL male/unsexed  Found in the Rio Estrella basin, Rio Grande do Sul (Ref. 6868). Also Ref. 127242. - 
Heptapteridae Acentronichthys leptos Eigenmann & Eigenmann, 1889 Fr endemic  Bagre (Portuguese), Bagrinho (Portuguese), Mandizinho (Portuguese)   11.00 cm TL male/unsexed  Found in coastal streams from Rio de Janeiro to Santa Catarina. Also known from the type locality, São Mateus in Espírito Santo (Ref. 36914). Also Ref. 6868, 127242. + 
Loricariidae Acestridium discus Haseman, 1911 Fr native    6.70 cm SL male/unsexed  Known from the lower Negro River basin (Ref. 36885). Type locality: Igarapé de Cachoeira Grande, near Manaos, Brazil (Ref. 26282). + 
Loricariidae Acestridium gymnogaster Reis & Lehmann A., 2009 Fr native    Known from the small tributaries to the middle Rio Madeira in Amazonas (Ref. 82432). - 
Loricariidae Acestridium scutatum Reis & Lehmann A., 2009 Fr native    Known from the small tributaries to the middle Rio Madeira in Amazonas (Ref. 82432). - 
Loricariidae Acestridium triplax Rodríguez & Reis, 2007 Fr native   5.55 cm SL male/unsexed  Found only in small forest creeks near Juruti, Pará State, lower rio Tapajós drainage, Amazon River basin (Ref. 75792). + 
Characidae Acestrocephalus acutus Menezes, 2006 Fr native   10.35 cm SL male/unsexed  Known from rio Tocantins and rio Tapajós drainages (Ref. 75890). + 
Characidae Acestrocephalus maculosus Menezes, 2006 Fr native   7.90 cm SL female  Found only in the tributaries of the upper Tocantins (Ref. 75890). + 
Characidae Acestrocephalus nigrifasciatus Menezes, 2006 Fr native   9.30 cm SL male/unsexed  Known from Rio Arinos and Rio Juruena, and rio Tapajós basin in Mato Grosso (Ref. 75890). + 
Characidae Acestrocephalus pallidus Menezes, 2006 Fr native    6.05 cm SL male/unsexed  Found only in rio Madeira and rio Machado, a tributary of rio Madeira (Ref. 75890). + 
Characidae Acestrocephalus sardina (Fowler, 1913) Fr native  Pirapuco miri (Portuguese)   15.60 cm SL male/unsexed ;21.70 cm SL female  Known from Madeira and Das Mortes River basins (Ref. 36811). Found in the tributaries of the rio Madeira, Mato Grosso, rio Jutaí and rio Negro, Amazonas (Ref. 75890). + 
Characidae Acestrocephalus stigmatus Menezes, 2006 Fr native   13.50 cm TL male/unsexed  Known from the rio Tocantins, rio das Mortes (tributary of rio Araguaia) and Rio Xingu (Ref. 75890). + 
Acestrorhynchidae Acestrorhynchus abbreviatus (Cope, 1878) Fr native  Cachorrinho (Creole, Portuguese), Ueua (Creole, Portuguese)  30.00 cm SL male/unsexed   - 
Acestrorhynchidae Acestrorhynchus altus Menezes, 1969 Fr native  Cachorrinho (Creole, Portuguese), Ueua (Creole, Portuguese), Jacundá (Portuguese), Joana guenza (Portuguese), Peixe cachorro (Portuguese), Peixe caxorro (Portuguese)   23.30 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38248). Collected from Lago Arari, ilha de Marajó, Pará (Ref. 27925). + 
Acestrorhynchidae Acestrorhynchus britskii Menezes, 1969 Fr native  Peixe cachorro (Creole, Portuguese), Peixe caxorro (Portuguese)  16.50 cm SL male/unsexed  Type locality, Represa de Três Marias, Rio Sao Francisco basin, Minas Gerais (Ref. 27925). + 
Acestrorhynchidae Acestrorhynchus falcatus (Bloch, 1794) Fr, Fi native  Ueua (Portuguese), Cachorinho (Portuguese), Cachorrinho (Portuguese), Dentudo (Portuguese), Dentudo dourado (Portuguese), Icanga (Portuguese), Matrinchã (Portuguese), Peixe cachorro (Portuguese), Piau cachorro (Portuguese), Pirapuco (Portuguese), Saicanga (Portuguese), Trinchã (Portuguese)   30.00 cm TL male/unsexed  Known from the Amazon (Ref. 38248), Machado (Ref. 38248) and Acre River basins (Ref. 97592). Recorded from the state of Para (Ref. 27188). Also Ref. 38248. + 
Acestrorhynchidae Acestrorhynchus falcirostris (Cuvier, 1819) Fr, Fi native  Peixe cachorro (Creole, Portuguese), Ueua (Creole, Portuguese), Anicauera (Portuguese), Cachorrinho (Portuguese), Dentudo (Portuguese), Piau cachorro (Portuguese), Pirapuco (Portuguese)   45.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38248). + 
Acestrorhynchidae Acestrorhynchus grandoculis Menezes & Géry, 1983 Fr native  Peixe cachorro (Creole, Portuguese), Ueua (Creole, Portuguese)   10.80 cm SL male/unsexed  Museum: mouth of Rio Urubaxi, Rio Negro, Amazonas, MZUSP 25863 (holotype, 10 cm SL) (Ref. 27925). Rio Negro: Arirará , MZUSP 25977; Mararuiá, MZUSP 25887; Rio Mararuiá, MZUSP 25912 - 25916; Paraná do Jacaré, MZUSP 25917; Massarabi, MZUSP 25931 (Ref. 27925). - 
Acestrorhynchidae Acestrorhynchus heterolepis (Cope, 1878) Fr native  Peixe cachorro (Creole, Portuguese), Ueua (Creole, Portuguese)   40.80 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38248). - 
Acestrorhynchidae Acestrorhynchus isalineae Menezes & Géry, 1983 Fr native    10.10 cm SL male/unsexed  Museum: Rio dos Marmelos, Rio Madeira basin, 110 km east of Humaitá along rodovia Transamazônica, Amazonas, MZUSP 25849 (holotype of A. isalineae, 8.9 cm SL) (Ref. 27925). - 
Acestrorhynchidae Acestrorhynchus lacustris (Lütken, 1875) Fr, Fi native  Peixe cadela (Portuguese), Peixe cachorro (Creole, Portuguese), Ueua (Creole, Portuguese), Bicuda (Portuguese), Peixe-cadela (Portuguese) scarce (very unlikely) 31.80 cm SL male/unsexed 10.7 TL Known from São Francisco (Ref. 38248) and Piracicaba rivers (Ref. 50076). + 
Acestrorhynchidae Acestrorhynchus maculipinna Menezes & Géry, 1983 Fr native  Peixe cachorro (Creole, Portuguese), Ueua (Creole, Portuguese)  7.90 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38248). Museum: Rio Preto da Eva, between Manaus and Itacoatiara, Amazonas, MZUSP 25861 (holotype of A. maculipinna, 7.9 cm SL) (Ref. 27925). - 
Acestrorhynchidae Acestrorhynchus microlepis (Jardine, 1841) Fr native  Cachorinho (Portuguese), Bada (Portuguese), Cachorrinho (Portuguese), Piau cachorro (Portuguese), Pirá andirá (Portuguese), Ueua (Portuguese)   37.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 38248). + 
Acestrorhynchidae Acestrorhynchus minimus Menezes, 1969 Fr native  Cachorrinho (Creole, Portuguese), Ueua (Creole, Portuguese)   6.30 cm SL male/unsexed  Type locality, Lago Jacaré, Rio Trombetas, Amazon R. basin, DZSP 4608 (holotype of A. minimus, 6.3 cm TL) (Ref. 27925). + 
Acestrorhynchidae Acestrorhynchus nasutus Eigenmann, 1912 Fr native  Cachorrinho (Creole, Portuguese), Ueua (Creole, Portuguese)   6.90 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38248). + 
Acestrorhynchidae Acestrorhynchus pantaneiro Menezes, 1992 Fr, Fi native  Peixe-cachorro (Portuguese), Peixe cachorro (Creole, Portuguese), Dourado-cachorro (Portuguese)   35.20 cm TL male/unsexed  Known from the Uruguay River (Ref. 79585). Museum: Rio Cuiabá, Volta Grande, Município de Santo Antônio do Leverger, Mato Grosso, MZUSP 40256 (holotype of A. pantaneiro, 14.5 cm SL) (Ref. 27925). Also Ref. 38248. + 
Achiridae Achirus achirus (Linnaeus, 1758) Fr, Br, M native  Linguado (Portuguese), Chula (Portuguese), Linguado-lixa (Portuguese), Soia (Portuguese), Solha (Portuguese), Solha verdadeira (Portuguese), Tapa (Portuguese)  37.00 cm TL male/unsexed   + 
Characidae Acinocheirodon melanogramma Malabarba & Weitzman, 1999 Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese), Piaba (Portuguese)  3.77 cm SL male/unsexed  Recorded from São Francisco and Jequitinhonha River basins (Ref. 37055). - 
Serrasalmidae Acnodon normani Gosline, 1951 Fr native  Pacu (Portuguese)   19.90 cm TL male/unsexed  Occurs in Amazon, Xingu and Tocantins River basins (Ref. 39031). + 
Serrasalmidae Acnodon senai Jégu & Santos, 1990 Fr native   13.20 cm SL male/unsexed  Known from Jari River basin (Ref. 39031). Museum: beach at downstream of Rio Jari, Amapà, Carapatinho I., MZUSP 40050 (paratypes of A. senai) (Ref. 27925). - 
Apteronotidae Adontosternarchus balaenops (Cope, 1878) Fr native    25.00 cm TL male/unsexed  Found in the Amazon River (Ref. 36886). + 
Apteronotidae Adontosternarchus clarkae Mago-Leccia, Lundberg & Baskin, 1985 Fr native    18.60 cm TL male/unsexed  Found in the Ngero River basin (Ref. 36886). + 
Apteronotidae Adontosternarchus devenanzii Mago-Leccia, Lundberg & Baskin, 1985 Fr native   18.60 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). + 
Apteronotidae Adontosternarchus duartei de Santana & Vari, 2012 Fr native   18.50 cm TL male/unsexed   - 
Apteronotidae Adontosternarchus nebulosus Lundberg & Cox Fernandes, 2007 Fr native    21.80 cm TL male/unsexed  Known from the Amazon basin (Ref. 78211). + 
Apteronotidae Adontosternarchus sachsi (Peters, 1877) Fr native   32.20 cm TL male/unsexed   + 
Cichlidae Aequidens diadema (Heckel, 1840) Fr native   11.80 cm SL male/unsexed  Known from the Amazon River basin, in the upper Negro River (Ref. 36377). + 
Cichlidae Aequidens epae Kullander, 1995 Fr endemic    11.30 cm SL male/unsexed  Known from Rio Amazonas basin, in the lower Rio Tapajós drainage near Jacareacanga and São Luis, Pará (Ref. 36377). Type locality: Río Tapajós drainage, igarapé in Barreirinha, Pará, Brazil. + 
Cichlidae Aequidens gerciliae Kullander, 1995 Fr endemic    12.80 cm SL male/unsexed ;9.74 cm SL female  Found only in the Amazon River basin in the upper Rio Aripuanã, near Salto (or Cachoeira) de Dardanelos and in a headwater stream on the Juína-Vilhena road (Ref. 26647). Also Ref. 36377. + 
Cichlidae Aequidens mauesanus Kullander, 1997 Fr native    13.40 cm SL male/unsexed  Found in the lower rio Maués, a tributary to the paraná Uraria, a channel of Amazon and along the rio Arapiuns, a tributary fo the lower rio Tapajos (Ref. 26676). Also Ref. 36377. - 
Cichlidae Aequidens michaeli Kullander, 1995 Fr endemic    20.00 cm TL male/unsexed  Known only from Amazon River basin in the lower Xingu River at Altamira and Belo Monte (Ref. 26647). Also Ref. 36377. + 
Cichlidae Aequidens pallidus (Heckel, 1840) Fr endemic  Acará (Portuguese), Acarra (Portuguese), Cará de grota (Portuguese), Cará de praia (Portuguese), Cará luzia (Portuguese)   14.30 cm SL male/unsexed  Known from the Amazon River basin, in the middle and lower Negro River, Uatumã, Preto da Eva, and Puraquequara rivers.(Ref. 36377). Type locality: Rio Negro of Rio Amazonas, South America (Ref. 12965). Also Ref. 4537, 12251. + 
Cichlidae Aequidens plagiozonatus Kullander, 1984 Fr native  Cará (Portuguese), Acará (Portuguese), Carazinho (Portuguese)   10.30 cm SL male/unsexed  Type locality: Internal lakes of the Piquiri-Itiquira system, Itiquira, Mato Grosso, MZUSP 28-732 (holotype of Aequidens plagiozonatus, 9.76 cm SL) (Ref. 86505). Known from the Amazon River basin in the upper Guaporé River drainage and the Paraná River basin in the upper Paraguay River drainage (Ref. 36377). + 
Cichlidae Aequidens rondoni (Miranda Ribeiro, 1918) Fr endemic   9.70 cm SL male/unsexed  Known from the Amazon River basin, in the upper Tapajós River basin (Ref. 36377). + 
Cichlidae Aequidens tetramerus (Heckel, 1840) Fr native  Carà (Portuguese), Acará (Portuguese), Acará dola (Portuguese), Acará pixuna (Portuguese), Acará-cuaima (Portuguese), Acará-pixuna (Portuguese), Acará-tonto (Portuguese), Acaracuima (Portuguese), Acarácuíma (Portuguese), Acaradola (Portuguese), Acarra miri (Portuguese)   19.20 cm TL male/unsexed  Known from the Amazon (Ref. 36377) and Machado River basins (Ref. 97589). Found in Parnaiba and Tocantins drainages (Ref. 36377). Also Ref. 4537. + 
Cichlidae Aequidens tubicen Kullander & Ferreira, 1991 Fr endemic    11.60 cm SL male/unsexed  Type locality, Estado do Pará, Río Trombetas drainage. Reserva Biológica de Trombetas, igarapé at km 4 on the road to Perirnetral Norte, MZUSP 15887 (holotype of Aequidens tubicen, 10.38 cm SL, adult female) (Ref. 86501). Known only from the Amazon River basin in the Trombetas Rriver close to Cachoeira Porteira (Ref. 36377). + 
Cichlidae Aequidens viridis (Heckel, 1840) Fr native  Acará cascudo (Portuguese)   16.50 cm SL male/unsexed  Occurs in the Guaporé River, Amazon River basin (Ref. 36377). Also Ref. 4537. + 
Doradidae Agamyxis pectinifrons (Cope, 1870) Fr native    15.00 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Auchenipteridae Ageneiosus akamai Ribeiro, Rapp Py-Daniel & Walsh, 2017 Fr native   17.41 cm SL male/unsexed  Type locality of the holotype of Ageneiosus akamai: Rio Purus, Beruri (Ref. 124585). - 
Auchenipteridae Ageneiosus apiaka Ribeiro, Rapp Py-Daniel & Walsh, 2017 Fr native   20.34 cm SL male/unsexed  Type locality of the holotype of Ageneiosus apiaka: Teles Pires River, below the Sete Quedas waterfall, Rio Tapajós basin (Ref. 124585). - 
Auchenipteridae Ageneiosus inermis (Linnaeus, 1766) Fr, Fi native  Palmito (Portuguese), Andubé (Portuguese), Bocarra (Portuguese), Bocudo (Portuguese), Doncellé (Portuguese), Fidalgo (Portuguese), Madubé (Portuguese), Mandibé (Portuguese), Mandobé (Portuguese), Mandube (Portuguese), Mandubé (Portuguese), Mandubi (Portuguese), Manduvê (Portuguese), Peixe palmito (Portuguese)   64.80 cm TL male/unsexed  Also Ref. 37098, 81048. + 
Auchenipteridae Ageneiosus intrusus Ribeiro, Rapp Py-Daniel & Walsh, 2017 Fr native   27.91 cm SL male/unsexed  Known from middle and lower Amazon River (Ref. 124585). - 
Auchenipteridae Ageneiosus lineatus Ribeiro, Rapp Py-Daniel & Walsh, 2017 Fr native   16.00 cm SL male/unsexed  Type locality of the holotype of Ageneiosus lineatus: Rio Negro, Rio Jau, Novo Airao, Amazonas (Ref. 124585). - 
Auchenipteridae Ageneiosus militaris Valenciennes, 1835 Fr native  Fidalgo (Portuguese), Manduvê (Portuguese), Manduvi (Portuguese), Matrinchã (Portuguese), Palmito de ferrão (Portuguese), Palmito de-ferrao (Portuguese)   30.00 cm SL male/unsexed    + 
Auchenipteridae Ageneiosus polystictus Steindachner, 1915 Fr native  Mandobé (Portuguese)  45.00 cm SL male/unsexed  Known from Negro and lower Branco River basins (Ref. 37098). + 
Auchenipteridae Ageneiosus ucayalensis Castelnau, 1855 Fr, Fi native  Bocudo (Portuguese), Fidalgo (Portuguese), Fidalgo comprido (Portuguese), Madubé (Portuguese), Mampará (Portuguese), Mandibé (Portuguese), Mandubé (Portuguese), Mandubi (Portuguese), Manduvê (Portuguese), Palmito-de-ferrão (Portuguese), Patinha (Portuguese), Ximbé (Portuguese)   35.20 cm SL male/unsexed  Found in fish markets in Santarém (Ref. 12202). + 
Auchenipteridae Ageneiosus uranophthalmus Ribeiro & Rapp Py-Daniel, 2010 Fr native     Found in river channels of the central Amazon basin (Ref. 83902). - 
Auchenipteridae Ageneiosus vittatus Steindachner, 1908 Fr native    22.00 cm SL male/unsexed    - 
Triportheidae Agoniates anchovia Eigenmann, 1914 Fr native    14.80 cm SL male/unsexed    - 
Triportheidae Agoniates halecinus Müller & Troschel, 1845 Fr native  Maiaca (Portuguese), Apapai (Portuguese)   26.80 cm TL male/unsexed    + 
Pimelodidae Aguarunichthys inpai Zuanon, Rapp Py-Daniel & Jégu, 1993 Fr endemic    42.00 cm SL male/unsexed  Known from the middle Amazon River basin (Ref. 36506). - 
Pimelodidae Aguarunichthys tocantinsensis Zuanon, Rapp Py-Daniel & Jégu, 1993 Fr endemic  Jundiá (Portuguese)   31.70 cm SL male/unsexed  Known from Tocantins River basin (Ref. 36506). + 
Pimelodidae Aguarunichthys torosus Stewart, 1986 Fr native    34.60 cm SL male/unsexed    + 
Aspredinidae Amaralia hypsiura (Kner, 1855) Fr native    13.30 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36695). Type locality, Rio Branco, Amazonas (Ref. 6868). + 
Aspredinidae Amaralia oviraptor Friel & Carvalho, 2016 Fr native   12.28 cm SL male/unsexed  Found in Paraná drainage and Paraguay River Basin (Ref. 111083). - 
Characidae Amazonichthys camelierae Esguícero & Mendonça, 2023 Fr native    type locality of Amazonichthys camelierae, Pará State: Jacareacanga Municipality: Rio Amazonas, Rio Tapajós, Vila de Mamãe Anã, before KM 1. Known from the middle region of the Rio Tapajós, a tributary of the Rio Amazonas basin, at the Amazonas, Mato Grosso, and Pará States (Ref. 130247). - 
Characidae Amazonichthys lindeae (Géry, 1973) Fr native    2.49 cm SL male/unsexed  Type locality of Axelrodia lindeae, Pará́ State, Óbidos Municipality: Rio Amazonas, Igarapé Curuçambá, about 9 km north of Óbidos (3 km from Óbidos-airport). Found in the Curuçamba River on the lower Amazon basin and the middle Madeira River basin (Ref. 38376). Also Ref. 598. - 
Characidae Amazonspinther dalmata Bührnheim, Carvalho, Malabarba & Weitzman, 2008 Fr native    1.98 cm SL male/unsexed  Known from Rio Purus and Rio Madeira basins in State of Amazonas (Ref. 79887). Reported from Machado river basin (Ref. 97589). - 
Engraulidae Amazonsprattus scintilla Roberts, 1984 Fr native   2.00 cm SL male/unsexed   + 
Doradidae Amblydoras affinis (Kner, 1855) Fr native    13.20 cm SL male/unsexed    + 
Doradidae Amblydoras monitor (Cope, 1872) Fr native   9.00 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). - 
Doradidae Amblydoras nheco (Higuchi, Birindelli, Sousa & Britski, 2007) Fr native   7.00 cm SL male/unsexed   + 
Crenuchidae Ammocryptocharax elegans Weitzman & Kanazawa, 1976 Fr native    3.25 cm SL male/unsexed  Occurs in the Amazon River (Ref. 37059). Recorded from the Guajara Mirim, Estado de Rondonia (Ref. 13683). + 
Crenuchidae Ammocryptocharax minutus Buckup, 1993 Fr native   2.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37059). Museum: Rio Urubaxi, beach near confluence with Rio Negro, MZUSP 43671 (holotype, 1.97 cm SL) (Ref. 13683). + 
Trichomycteridae Ammoglanis amapaensis Mattos, Costa & Gama, 2008 Fr native   1.78 cm SL male/unsexed  Type locality, Pparque Nacional Montanhas do Tumucumaque, Município Serra do Navio, rio Jari basin, rio Mapaoni, estado do Amapá, IEPA 2497 (holotype of Ammoglanis amapaensis, 1.52 cm SL). Collected from Estado do Amapa, in Rios Amapari, Araguari and Jari basins (Ref. 78711). - 
Trichomycteridae Ammoglanis diaphanus Costa, 1994 Fr native   1.87 cm SL male/unsexed  Known only the from type locality: stream tributary to Rio Javaés, Rio Araguaia basin, Tocantins (Ref. 26653). Also Ref. 39970. - 
Anablepidae Anableps anableps (Linnaeus, 1758) Fr, Br native  Quatro-olhos (Portuguese), Tariota (Portuguese), Tralhote (Portuguese), Tralhoto (Portuguese)   30.00 cm TL male/unsexed  Found in mangrove areas along the coastline. Also Ref. 4537, 5217, 26938. + 
Anablepidae Anableps microlepis Müller & Troschel, 1844 Fr, Br native  Tralhote (Portuguese), Quatro-olhos (Portuguese), Tariota (Portuguese), Tralhoto (Portuguese)  32.00 cm TL male/unsexed  Also Ref. 4537, 5217. + 
Rivulidae Anablepsoides amanan (Costa & Lazzarotto, 2008) Fr native   2.81 cm SL male/unsexed ;2.79 cm SL female  Type locality, Pools at the floodplains of Igarapé do Baré, near Cano do Lago de Beleza, Lago Amanã system, Reserva de Desenvolvimento Sustentável Amanã, Japurá-Solimões drainage, Rio Amazonas basin, Município de Maraã, Estado do Amazonas, UFRJ 6571 (holotype of Rivulus amanan, 2.65 cm SL, male). Known only from 2 localities in northern Brazil, near Igarapé do Baré, a stream draining into lago Amanã, Japurá-Solimões drainage system, rio Amazonas basin (Ref. 78702). - 
Rivulidae Anablepsoides atratus (Garman, 1895) Fr native    4.00 cm TL male/unsexed  Known from the Amazon River (Ref. 36579). + 
Rivulidae Anablepsoides bahianus (Huber, 1990) Fr endemic   5.50 cm TL male/unsexed   - 
Rivulidae Anablepsoides beniensis (Myers, 1927) Fr native    4.00 cm TL male/unsexed  Known from the Mamoré-Guaporé River basin (Ref. 36579). + 
Rivulidae Anablepsoides cajariensis (Costa & De Luca, 2011) Fr native   5.62 cm SL male/unsexed  Known from Cajari River drainage, lower Amazonas River basin in northeastern Brazil (Ref. 86530). - 
Rivulidae Anablepsoides cearensis (Costa & Vono, 2009) Fr native    Known from São Gonçalo do Amarante, Ceará in northeastern Brazil (Ref. 81224). - 
Rivulidae Anablepsoides gamae Costa, Bragança & Amorim, 2013 Fr native   2.22 cm SL male/unsexed ;2.18 cm SL female  Found in the Jari river drainage, lower Amazonas river basin in Amapá state (Ref. 94717). - 
Rivulidae Anablepsoides henschelae Costa, Bragança & Amorim, 2013 Fr native   2.25 cm SL male/unsexed  Found in a pool adjacent to stream about 35 km W of Jundiá, road BR-431, Jauaperi river drainage in Roraima state (Ref. 94717). - 
Rivulidae Anablepsoides igneus (Huber, 1991) Fr native   15.00 cm TL male/unsexed ;9.00 cm TL female  Amapa. + 
Rivulidae Anablepsoides jari Costa, Bragança & Amorim, 2013 Fr native   3.10 cm SL male/unsexed ;2.45 cm SL female  Found in the lower Jari river drainage, Amazonas river basin in northern Brazil (Ref. 94717). - 
Rivulidae Anablepsoides limoncochae (Hoedeman, 1962) Fr native   7.50 cm TL male/unsexed   + 
Rivulidae Anablepsoides luitalimae Nielsen, 2016 Fr native   3.72 cm SL male/unsexed ;3.93 cm SL female  Type locality of the holotype of Anablepsoides luitalimae: flooded area at an urban forest fragment, middle rio Madeira basin near Porto Velho, Rondonia (Ref. 128688). - 
Rivulidae Anablepsoides micropus (Steindachner, 1863) Fr endemic   7.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36579). - 
Rivulidae Anablepsoides ornatus (Garman, 1895) Fr native    4.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Anablepsoides ottonii Costa, Bragança & Amorim, 2013 Fr native   2.22 cm SL male/unsexed ;2.25 cm SL female  Found in the Caurés river drainage, a tributary of the Negro river, Amazonas river basin in Amazonas state (Ref. 94717). - 
Rivulidae Anablepsoides roraima Costa, Bragança & Amorim, 2013 Fr native   3.18 cm SL male/unsexed ;2.90 cm SL female  Known from the middle Branco river drainage, Amazonas the river basin in northern Brazil (Ref. 94717). + 
Rivulidae Anablepsoides taeniatus (Fowler, 1945) Fr native    6.00 cm TL male/unsexed  Found in the Purus and Acre River basins (Ref. 97592). - 
Rivulidae Anablepsoides tocantinensis (Costa, 2010) Fr native    Known from the Tocantins River drainage (Ref. 59043). - 
Rivulidae Anablepsoides urophthalmus (Günther, 1866) Fr endemic  Pirapitanga (Portuguese), Rívulo dourado (Portuguese)  7.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36579). + 
Rivulidae Anablepsoides urubuiensis Costa, 2013 Fr native    Type locality of Anablepsoides urubuiensis from a creek adjacent to Urubuí River, Amazonas, Brazil, UFRJ 6770 (Ref. 93231). - 
Rivulidae Anablepsoides vieirai Nielsen, 2016 Fr native   3.69 cm SL female  Type locality of the holotype of Anablepsoides vieirai: rio Parnaíba basin, spring Riacho Joana, near Duque Bacelar (Ref. 128688). - 
Rivulidae Anablepsoides xanthonotus (Ahl, 1926) Fr endemic   7.50 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36579). Also Ref. 27139. - 
Rivulidae Anablepsoides xinguensis (Costa, 2010) Fr native    Known from the lower Xingu River drainage, eastern Amazonas River basin in northeastern Brazil (Ref. 84054). - 
Doradidae Anadoras insculptus (Miranda Ribeiro, 1912) Fr native     - 
Doradidae Anadoras regani (Steindachner, 1908) Fr native  quiri-quiri (Portuguese)  11.00 cm SL male/unsexed  Found in Pará (Ref. 6868). Known from the Amazon River basin (Ref. 37054). - 
Doradidae Anadoras weddellii (Castelnau, 1855) Fr native  Carataí (Portuguese), Uarioroch (Portuguese)   15.00 cm SL male/unsexed    + 
Engraulidae Anchoa spinifer (Valenciennes, 1848) Fr, Br, M native  Sardinha (Portuguese), Arenque (Portuguese), Arenque-da-noite (Portuguese), Enchoveta (Portuguese), Manjuba (Portuguese), Manjuba-savelha (Portuguese), Mulatinha (Portuguese), Sardinha de gato (Portuguese), Sardinha vermelha (Portuguese), Sardinha-amarela (Portuguese)  24.00 cm TL male/unsexed   + 
Engraulidae Anchovia surinamensis (Bleeker, 1865) Fr, Br native  Maiacá (Portuguese), Manjuba (Portuguese), Sardinha-do-gato (Portuguese)  15.00 cm TL male/unsexed  Reported from above Manaus and Rio Janaperi at least 80 km above its junction with the Rio Negro. Also Ref. 12225. + 
Engraulidae Anchoviella alleni (Myers, 1940) Fr native    8.80 cm SL male/unsexed   + 
Engraulidae Anchoviella carrikeri Fowler, 1940 Fr native    6.50 cm SL male/unsexed  Known from the Amazon River basin (Ref. 50628). + 
Engraulidae Anchoviella guianensis (Eigenmann, 1912) Fr, Br native  Sardinha (Portuguese)   11.30 cm TL male/unsexed  Recorded from Rio Branco, Roraima (Ref. 89861). + 
Engraulidae Anchoviella jamesi (Jordan & Seale, 1926) Fr native    5.02 cm SL male/unsexed  Recorded from the rio Tefé, Jurupari, Amazonas (Ref. 89861). + 
Engraulidae Anchoviella juruasanga Loeb, 2012 Fr native    5.28 cm SL male/unsexed  Known from the tributaries of the middle and lower Amazon basin including rio Tapajós, rio Negro, rio Branco, rio Madeira, rio Trombetas, rio Tocantins, rio Maicá, and rio Jari (Ref. 89861). - 
Engraulidae Anchoviella lepidentostole (Fowler, 1911) Fr, Br, M, Fi native  Sardinha (Portuguese), Don-don (Portuguese), Manjuba (Portuguese), Manjubinha (Portuguese), Sardinha selvagem (Portuguese)  18.00 cm TL male/unsexed 8.8 TL Captured in great numbers during the warmer months in the region of Rio Ribiera de Iguape on the coast of Sao Paolo (Ref. 189). Caught by shrimp trawl in Pirambu, Sergipe (Ref. 118626). + 
Engraulidae Anchoviella sanfranciscana Barbosa, Gomes da Silva, da Rocha Araújo & Carvalho, 2017 Fr, Br native   12.80 cm SL male/unsexed  Known from the estuary of the São Francisco River in the region of Cabeço: close to the sea in the municipality of Brejo Grande, State of Sergipe; and upstream near to the city of Penedo, State of Alagoas (Ref. 116921). + 
Engraulidae Anchoviella vaillanti (Steindachner, 1908) Fr endemic  Manjuba (Portuguese), Pilombeta (Portuguese)   6.80 cm SL male/unsexed  Known from the middle São Francisco River (Ref. 50628). + 
Loricariidae Ancistomus feldbergae (de Oliveira, Rapp Py-Daniel, Zuanon & Rocha, 2012) Fr native  L12 (English), L13 (English)  17.08 cm SL male/unsexed  Known so far from the Rio Xingu basin. Speciemens were recorded from Rio Xingu (Costa Junior, Ilha de Babaquara, and Gorgulho da Rita) and its tributaries, the Rio Iriri and Rio Curua (Ref. 91751). + 
Loricariidae Ancistomus micrommatos (Cardoso & Lucinda, 2003) Fr native   11.85 cm SL male/unsexed  Known only from the upper rio Tocantins and its tributaries. Type locality, between Minaçu and Cavalcante, at site of future hydroelectric dam of Serra da Mesa, rio Tocantins, Goiás, MNRJ 20873 (holotype, 10.29 cm SL, male) (Ref. 49598). - 
Loricariidae Ancistomus snethlageae (Steindachner, 1911) Fr endemic   22.00 cm TL male/unsexed  Known from Tapajós River basin (Ref. 36713). Also Ref. 6868. + 
Loricariidae Ancistomus spilomma (Cardoso & Lucinda, 2003) Fr native   14.21 cm SL male/unsexed  Known from lower and upper rio Tocantins drainage. Type locality, Núcleo de Estudos Ambientais, rio Tocantins near mouth of rio Lajeado, Porto Franco, Tocantins, MCP 28425 (holotype, 13.05 cm SL) (Ref. 49598). - 
Loricariidae Ancistomus spinosissimus (Cardoso & Lucinda, 2003) Fr native   12.69 cm SL male/unsexed  Known only from the middle and upper rio Tocantins and its tributaries (Ref. 49598). Type locality, Rio Maranhão, near mouth of the rio Tocantinzinho, border of Niquelândia and Campinaçu, 13°5'25"S, 48°19'08"W, Goiás (Ref. 50838). - 
Loricariidae Ancistrus abilhoai Bifi, Pavanelli & Zawadzki, 2009 Fr native    10.62 cm SL male/unsexed ;8.49 cm SL female  Type locality, Paraná State, Lapa, middle Rio Iguaçu basin, Rio Iguaçu, MZUSP 104116 (holotype of Ancistrus abilhoai, 9.93 cm SL, male). Commonly found in upper and middle Rio Iguaçu basin, Southern Brazil, and one single lot at lower Rio Iguaçu (Ref. 83296). - 
Loricariidae Ancistrus agostinhoi Bifi, Pavanelli & Zawadzki, 2009 Fr native    9.61 cm SL male/unsexed ;7.63 cm SL female  Type locality, Paraná State, Foz do Jordão, lower Rio Iguaçu basin, Rio Jordão, MZUSP 104118 (holotype of Ancistrus agostinhoi, 9.61 cm SL, male). Known only from the Rio Jordão drainage, affluent of lower Rio Iguaçu, Southern Brazil (Ref. 83296). - 
Loricariidae Ancistrus aguaboensis Fisch-Muller, Mazzoni & Weber, 2001 Fr native   6.70 cm SL male/unsexed  Known only from its type locality, a restricted area 10 km from Minaçú on road Minaçú-Campinaçu, small tributary of the upper rio Tocantins, córrego Água Boa, Minaçú, Goiás, Brazil (Ref. 40950). Also Ref. 36713. + 
Loricariidae Ancistrus brevipinnis (Regan, 1904) Fr endemic  Cascudo (Portuguese), Cascudo de espinhos (Portuguese)  10.70 cm SL male/unsexed  Known from Rio Grande do Sul (Ref. 6868). Found in Laguna dos Patos basin (Ref. 36713). Recorded from Betari River basin, Southeastern Brazil (Ref. 38979). + 
Loricariidae Ancistrus cirrhosus (Valenciennes, 1836) Fr misidentification  Cascudo roseta (Portuguese)   8.90 cm SL male/unsexed  Occurrence in this country not confirmed by S. Fisch-Muller; probably a misidentification. + 
Loricariidae Ancistrus claro Knaack, 1999 Fr endemic   6.60 cm SL male/unsexed  Known from Cuiabá River basin in upper Paraguay River drainage (Ref. 36713). + 
Loricariidae Ancistrus cryptophthalmus Reis, 1987 Fr endemic   6.00 cm SL male/unsexed  Known from São Vicente and Angélica-Bezerra cave system in upper Paraná River, Tocantins River drainage (Ref. 36713). Type locality: Caverna Passa Três, ca. 300 m into the cave, Rio Sao Vicente system, Sao Domingos, Goiás (Ref. 27299). + 
Loricariidae Ancistrus damasceni (Steindachner, 1907) Fr endemic    6.50 cm SL male/unsexed  Known from the upper Parnaíba River basin (Ref. 36713). Also Ref. 6868. + 
Loricariidae Ancistrus dolichopterus Kner, 1854 Fr native  Cascudo negro aba branca (Portuguese), Bodó seda (Portuguese)  14.50 cm SL male/unsexed  Known from the upper and middle Amazon River basin and from Negro, lower Trombetas, Tefé, Madeira and Tapajós River basins. (Ref. 36713). + 
Loricariidae Ancistrus dubius Eigenmann & Eigenmann, 1889 Fr native  Vieja (Portuguese)  12.60 cm SL male/unsexed  Found in Gurupa (Ref. 6868). Also Ref. 36713. - 
Loricariidae Ancistrus formoso Sabino & Trajano, 1997 Fr endemic  Cascudo (Portuguese)   7.90 cm SL male/unsexed  Known from Buraco do Ducho Cave in Formoso phreatic system (Ref. 36713). + 
Loricariidae Ancistrus fulvus (Holly, 1929) Fr endemic   8.80 cm SL male/unsexed  Known from the Acará River basin in lower Amazon drainage (Ref. 36713). Also Ref. 6868. - 
Loricariidae Ancistrus hoplogenys (Günther, 1864) Fr native  Bodozinho (Portuguese)   15.80 cm SL male/unsexed  Found in Capin River, Para (Ref. 6868). + 
Loricariidae Ancistrus jataiensis Fisch-Muller, Cardoso, da Silva & Bertaco, 2005 Fr native   5.40 cm SL male/unsexed  Known only from the type locality, a small tributary of the rio Vermelho, upper Tocantins basin (Ref. 54498). - 
Loricariidae Ancistrus latifrons (Günther, 1869) Fr native   15.40 cm SL male/unsexed  Known from Solimões River basin (Ref. 36713). - 
Loricariidae Ancistrus leoni de Souza, Taphorn & Armbruster, 2019 Fr native   8.16 cm SL male/unsexed  Known from Rio Negro, São Gabriel rapids, Amazonas state (Ref. 119730). - 
Loricariidae Ancistrus leucostictus (Günther, 1864) Fr native    10.00 cm SL male/unsexed   + 
Loricariidae Ancistrus lithurgicus Eigenmann, 1912 Fr native   13.20 cm SL male/unsexed  Recorded from Machado river basin (Ref. 97589). - 
Loricariidae Ancistrus maculatus (Steindachner, 1881) Fr endemic   11.80 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36713). Found in Obidos (Ref. 6868). - 
Loricariidae Ancistrus mattogrossensis Miranda Ribeiro, 1912 Fr native    No report of other specimen other than the probably lost paratypes (Ref. 36713). - 
Loricariidae Ancistrus maximus de Oliveira, Zuanon, Zawadzki & Py-Daniel, 2015 Fr native   20.08 cm SL male/unsexed   - 
Loricariidae Ancistrus minutus Fisch-Muller, Mazzoni & Weber, 2001 Fr endemic   5.70 cm SL male/unsexed  Type locality, a left bank tributary of the upper rio Tocantins, córrego Batéis, Minaçú, Goiás (Ref. 40950). Also Ref. 36713. + 
Loricariidae Ancistrus miracollis Bifi, de Oliveira & Rapp Py-Daniel, 2019 Fr native   6.74 cm SL male/unsexed  Type locality of the holotype of Ancistrus miracollis: Rio Madeira basin, tributary of Rio Sucunduri, igarapé do Mureru, Apui (Ref. 128813). - 
Loricariidae Ancistrus mullerae Bifi, Pavanelli & Zawadzki, 2009 Fr native    12.48 cm SL male/unsexed ;7.98 cm SL female  Type locality, Paraná State, Três Barras do Paraná, lower Rio Iguaçu basin, affluent of Rio Iguaçu, Rio Guarani, MZUSP 104121 (holotype of Ancistrus mullerae, 11.91 cm SL, male). Known from the ower Rio Iguaçu basin, upstream from Cataratas do Iguaçu, Southern Brazil (Ref. 83296).. - 
Loricariidae Ancistrus multispinis (Regan, 1912) Fr endemic  Barbadinho (Portuguese)   14.20 cm SL male/unsexed  Known from the Macacú River to the Maquiné River (Ref. 36713). Also Ref. 6868. + 
Loricariidae Ancistrus parecis Fisch-Muller, Cardoso, da Silva & Bertaco, 2005 Fr native   5.95 cm SL male/unsexed  Type locality, Mato Grosso: Campos de Júlio: rio Formiga (tributary of rio Juruena, upper rio Tapajós basin), on the road BR-364 (MT-235), between Campos de Júlio and Sapezal, MCP 35570 (holotype of Ancistrus parecis, 59.5 mm SL, male). Known from the upper rio Juruena of the rio Tapajós basin (Ref. 56914). - 
Loricariidae Ancistrus ranunculus Muller, Rapp Py-Daniel & Zuanon, 1994 Fr endemic  Cascudo preto velho (Portuguese)  19.50 cm TL male/unsexed  Known from Xingu and Tocantins River basins (Ref. 36713). + 
Loricariidae Ancistrus reisi Fisch-Muller, Cardoso, da Silva & Bertaco, 2005 Fr native   6.08 cm SL male/unsexed  Known from the upper Tocantins drainage in Tocantins State (Ref. 54498). - 
Loricariidae Ancistrus saudades de Souza, Taphorn & Armbruster, 2019 Fr native   10.75 cm SL male/unsexed  Known from the Takutu River drainage (Ref. 119730). - 
Loricariidae Ancistrus stigmaticus Eigenmann & Eigenmann, 1889 Fr endemic  Barbadinho (Portuguese), Cascudo (Portuguese)   15.20 cm SL male/unsexed  Known from the upper Araguaia River basin (Ref. 36713). Also Ref. 6868. - 
Loricariidae Ancistrus taunayi Miranda Ribeiro, 1918 Fr native  Cascudo de espinhos (Portuguese), Cascudo-roseta (Portuguese)  14.00 cm TL male/unsexed  Known from the Uruguay River basin (Ref. 36713, 79585). Also Ref. 6868. + 
Loricariidae Ancistrus tombador Fisch-Muller, Cardoso, da Silva & Bertaco, 2005 Fr native   6.28 cm SL male/unsexed  Known from small rivers of the rio Arinos basin, upper rio Tapajós drainage in Mato Grosso state (Ref. 54498). - 
Loricariidae Ancistrus verecundus Fisch-Muller, Cardoso, da Silva & Bertaco, 2005 Fr native   5.46 cm SL male/unsexed  Known from the upper rio Madeira basin (Ref. 56914). - 
Characidae Andromakhe saguazu (Casciotta, Almirón & Azpelicueta, 2003) Fr native    9.23 cm SL male/unsexed   - 
Characidae Andromakhe stenohalina (Messner, 1962) Fr native   7.76 cm SL male/unsexed   - 
Doradidae Anduzedoras oxyrhynchus (Valenciennes, 1821) Fr native  Cuyu cuyu (Portuguese)  32.30 cm SL male/unsexed   + 
Anguillidae Anguilla anguilla (Linnaeus, 1758) Fr, Br, M not established  Enguia (Portuguese)  122 cm TL male/unsexed ;133 cm TL female  Established in aquaculture through continuous importation. Has not established in the wild. + 
Anguillidae Anguilla japonica Temminck & Schlegel, 1846 Fr not established  Enguia (Portuguese)  150 cm TL male/unsexed  Has established in aquaculture through continuous importation. Has not established in the wild (Ref. 1739). + 
Hemiodontidae Anodus elongatus Agassiz, 1829 Fr, Fi native  Ubarana (Portuguese), Charuto (Portuguese), Cubiu orana (Portuguese), Flecheiro (Portuguese), Orana (Portuguese)   30.30 cm SL male/unsexed  Known from the Amazon (Japurá, Trombetas, Purus, Jutai, Solimões) and Ucayali River basins (Ref. 38289). Also Ref. 598, 12202. + 
Hemiodontidae Anodus orinocensis (Steindachner, 1887) Fr native  Ubarana (Portuguese)   27.50 cm SL male/unsexed  Known from the Amazon and Tocantins River basins (Ref. 38289). + 
Anostomidae Anostomoides laticeps (Eigenmann, 1912) Fr native  Araçu (Portuguese), Aracu cabeça-gorda (Portuguese), Piau (Portuguese), Sabão (Portuguese)   30.00 cm SL male/unsexed  Reported from fish markets in Santarém. + 
Anostomidae Anostomoides passionis Santos & Zuanon, 2006 Fr native   36.00 cm TL male/unsexed  Known from the rio Xingu (Ref. 57460). - 
Anostomidae Anostomus anostomus (Linnaeus, 1758) Fr native  Anostomo (Portuguese), Patuarangya (Portuguese)  16.00 cm TL male/unsexed  Known from the Amazon River (Ref. 36801). + 
Anostomidae Anostomus ternetzi Fernández-Yépez, 1949 Fr native  Anostomo (Portuguese), Aracu (Portuguese), Patuarangya (Portuguese), Ximboré (Portuguese) occasional (usually not seen) 12.00 cm TL male/unsexed  Known from Araguaia and Amazon River basins (Ref. 36801). Found in Machado river basin, Rondonia state (Ref. 97589). Also Ref. 598, 12225. + 
Parodontidae Apareiodon affinis (Steindachner, 1879) Fr native  Duro-duro (Portuguese), Canivete (Portuguese), Charuto (Portuguese)   18.10 cm TL male/unsexed 7.3 TL Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). Also found in the Uruguay River (Ref. 79585). Also Ref. 38267. + 
Parodontidae Apareiodon argenteus Pavanelli & Britski, 2003 Fr native   7.63 cm SL male/unsexed  Type locality, Rio Tocantins at Serra da Mesa, below the hydroelectric power dam, Minaçu, Goiás (Ref. 47883). - 
Parodontidae Apareiodon cavalcante Pavanelli & Britski, 2003 Fr native   5.64 cm SL male/unsexed  Type locality, Ribeirão do Padre, tributary on the right bank of the Rio Tocantinzinho, Cavalcante, Alto Tocantins, Goiás (Ref. 47883). - 
Parodontidae Apareiodon davisi Fowler, 1941 Fr native  Piaba-rei (Portuguese), Peixe-rei (Portuguese)   5.90 cm SL male/unsexed  Known from Jaguaribe and Paraíba River basins (Ref. 38267). Also Ref. 10296. + 
Parodontidae Apareiodon hasemani Eigenmann, 1916 Fr native  Canivete (Portuguese)  6.80 cm SL male/unsexed  Known from Rio Sao Francisco drainage (Ref. 10296). Also Ref. 38267. + 
Parodontidae Apareiodon ibitiensis Amaral Campos, 1944 Fr native  Canivete (Portuguese), Ibiti sucker characin (English), Ibiti sucker darter (English)   11.30 cm SL male/unsexed  Known from the Upper Paraná and upper São Francisco River basins (Ref. 38267). Foun in Cachoeira do Espraiado, Rio Mogi-Guaçu, Primera Cachoeira Grande depois de Soledade, Estado Minas Gerais (Ref. 33021). Museum: Rio Camanducaia, Monte Alegre, Sao Paulo, MZUSP 3411 (holotype of A. ibitiensis, 11.3 cm SL) (Ref. 27925). Also Ref. 35189. + 
Parodontidae Apareiodon itapicuruensis Eigenmann & Henn, 1916 Fr native    8.60 cm SL male/unsexed  Known from Rio Itapicuru drainage, Bahia (Ref. 10296). - 
Parodontidae Apareiodon machrisi Travassos, 1957 Fr native   7.40 cm SL male/unsexed  Known from Rio Tocantins-Araguaia basin (Ref. 10296, 47883, 38267). - 
Parodontidae Apareiodon piracicabae (Eigenmann, 1907) Fr native  Canivete (Portuguese)   12.00 cm SL male/unsexed  Known from the Upper Paraná and upper São Francisco River basins. (Ref. 38267). Museum: MZUSP 20467 (Ref. 13118). + 
Parodontidae Apareiodon tigrinus Pavanelli & Britski, 2003 Fr native   6.41 cm SL male/unsexed  Type locality, Córrego do Jacaré, close to the bridge, Santa Rita do Araguaia, Goiás (Ref. 47883). - 
Parodontidae Apareiodon vittatus Garavello, 1977 Fr native  Canivete (Portuguese)  14.50 cm SL male/unsexed  Known from the Iguaçu River basin (Ref. 38267). Museum: Rio Iguaçu, Bituruna, Estado do Paraná, MZUSP 12999 - 13000 (paratypes of A. vittatus) (Ref. 27925). Also Ref. 10296. - 
Parodontidae Apareiodon vladii Pavanelli, 2006 Fr native   11.34 cm SL male/unsexed  Known from Rio Piquiri, upper Rio Paraná basin in the State of Paraná (Ref. 57026). + 
Loricariidae Aphanotorulus emarginatus (Valenciennes, 1840) Fr, Fi native  Chicote (Portuguese), Acari (Portuguese), Acari pedra (Portuguese), Acari-de-praia (Portuguese), Bode carneiro (Portuguese), Bode praiano (Portuguese)   33.60 cm TL male/unsexed  Recorded from Machado river basin (Ref. 97589). Found in fish markets in Santarém (Ref. 12202). + 
Loricariidae Aphanotorulus gomesi (Fowler, 1942) Fr native  Cascudo (Portuguese)  14.30 cm SL male/unsexed  Type locality Ceará, Brazil (Ref. 26282, 6868). - 
Loricariidae Aphanotorulus horridus (Kner, 1854) Fr native  Cari de espinho (Portuguese), Cari de roseta (Portuguese), Cari rosa (Portuguese)  35.50 cm SL male/unsexed  Type locality: Forte do Principe, Rio Guapore, Brazil (Ref. 26282, 6868). - 
Loricariidae Aphanotorulus rubrocauda Oliveira, Rapp Py-Daniel & Zawadzki, 2017 Fr native   24.05 cm SL male/unsexed  Type locality of Aphanotorulus rubrocauda from Amazonas State, Apuí Municipality, rio Guariba, Resex do Guariba, tributary of the rio Aripuanã basin; INPA 33666 (Ref. 129297). - 
Loricariidae Aphanotorulus unicolor (Steindachner, 1908) Fr native    13.90 cm SL male/unsexed  Rio Madeira, ca. 200 mi. east of 63°54'W, Brazil (type locality of P. madeirae); near mouth of Rio Macaua, tributary of Rio Iaco, itself a tributary to Rio Purus, near Sena Madureira, (type locality of P. micropunctatus) (Ref. 26282, 6868). Museum: Rio Purus, NMW 44271 (lectotype, 11.31 cm SL) (Ref. 30403). + 
Characidae Aphyocharax agassizii (Steindachner, 1882) Fr native   3.32 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38382). Type locality: Jatuarana. - 
Characidae Aphyocharax alburnus (Günther, 1869) Fr native    8.00 cm male/unsexed  Known from the Amazon River basin (Ref. 38382). + 
Characidae Aphyocharax anisitsi Eigenmann & Kennedy, 1903 Fr native  Cauda vermelha (Portuguese), Lambari (Portuguese)   5.50 cm TL male/unsexed 18 TL Known from the Paraná River basin (Ref. 38382). + 
Characidae Aphyocharax dentatus Eigenmann & Kennedy, 1903 Fr native  Piquirão (Portuguese), Douradinho (Portuguese)   7.20 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 38382). Recorded from Caracu and Sao Pedro streams, tributaries of the Paraná river (Ref. 26076). Also Ref. 598. + 
Characidae Aphyocharax nattereri (Steindachner, 1882) Fr native    3.10 cm SL male/unsexed  Known from the Amazon and Paraguay basins (Ref. 38382). + 
Characidae Aphyocharax rathbuni Eigenmann, 1907 Fr native    7.10 cm SL male/unsexed  Found in Pantanal (Ref. 81048). + 
Characidae Aphyocheirodon hemigrammus Eigenmann, 1915 Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)   4.80 cm TL male/unsexed  Known from the upper Paraná River basin (Ref. 37055). Also Ref. 598. - 
Characidae Aphyodite apiaka Esguícero & Castro, 2017 Fr native   3.11 cm SL male/unsexed  Known only from Rio Aripuanã, lower Rio Madeira basin, Amazonas State (Ref. 116757). - 
Characidae Aphyodite grammica Eigenmann, 1912 Fr native    3.20 cm male/unsexed  Known from Rio Negro, upper Rio Amazonas basin (Ref. 116757). - 
Characidae Aphyodite tupebas Esguícero & Castro, 2017 Fr native   2.60 cm SL male/unsexed  Occurs in the lower Rio Solimões, including its tributary Rio Tefé in Amazonas State (Ref. 116757). - 
Rivulidae Aphyolebias boticarioi Costa, 2004 Fr native    Known from the upper Rio Purus drainage, Amazon basin in northern Brazil (Ref. 52556). - 
Achiridae Apionichthys dumerili Kaup, 1858 Fr, Br native  Linguado (Portuguese), Tapa (Portuguese)  13.10 cm TL male/unsexed  Known from estuarine areas of Oyapock, Amazon and Grajaú rivers; also enters low land freshwaters in Jari river (Ref. 36798). Also Ref. 49504. + 
Achiridae Apionichthys finis (Eigenmann, 1912) Fr native  Linguado (Portuguese), Sóia (Portuguese)   8.79 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36798). + 
Achiridae Apionichthys menezesi Ramos, 2003 Fr native   6.00 cm SL male/unsexed  Known from Rio Negro, Amazon basin (Ref. 49504). - 
Achiridae Apionichthys nattereri (Steindachner, 1876) Fr native  Linguado (Portuguese), Aramaçã (Portuguese), Aramaçá (Portuguese), Linguado de rio (Portuguese)  23.40 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36798). + 
Achiridae Apionichthys rosai Ramos, 2003 Fr native    3.45 cm SL male/unsexed  Known from the Amazon basin (Ref. 49504). - 
Achiridae Apionichthys seripierriae Ramos, 2003 Fr native   8.79 cm SL male/unsexed  Known from Rio Jurua and Rio Amazonas (Ref. 49504). - 
Cichlidae Apistogramma acrensis Staeck, 2003 Fr native     Found in the Purus and Acre River basins (Ref. 97592). + 
Cichlidae Apistogramma agassizii (Steindachner, 1875) Fr native  Agassízi (Portuguese), Acará (Portuguese)   4.20 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36377). + 
Cichlidae Apistogramma amoena (Cope, 1872) Fr misidentification   6.30 cm TL male/unsexed ;6.00 cm female  Recorded from this country (Ref. 7020). Occurrence of the species in the country is not confirmed (Ref. 36377). - 
Cichlidae Apistogramma angayuara Kullander & Ferreira, 2005 Fr native    2.47 cm SL male/unsexed ;2.27 cm SL female  Type locality, Rio Trombetas right bank, below cachoeira Vira Mundo, Pará State (Ref. 56722). - 
Cichlidae Apistogramma arua Römer & Warzel, 1998 Fr native    4.40 cm SL male/unsexed ;3.50 cm SL female  Known only from the type locality in a small igarapé (forest stream), a right-bank affluent of the Rio Arua, upstream of a waterfall near the village of Arua in the upper Arapiuns system, Para State. + 
Cichlidae Apistogramma bitaeniata Pellegrin, 1936 Fr native   4.60 cm SL male/unsexed  Known from Igarapé Preto and Lago Tefé (Ref. 36377). + 
Cichlidae Apistogramma borellii (Regan, 1906) Fr native  Cará (Portuguese), Acará (Portuguese)   3.90 cm SL male/unsexed  Known from Paraguay River basin (Ref. 36377). Also Ref. 4537. + 
Cichlidae Apistogramma brevis Kullander, 1980 Fr native    3.90 cm SL male/unsexed  Known from the Uaupés River basin, Amazon River basin (Ref. 36377). Type locality: Small igarapé of Lago Penera, 0°01'N, 67°21'W, Amazonas State, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Apistogramma cacatuoides Hoedeman, 1951 Fr native   5.00 cm SL male/unsexed   + 
Cichlidae Apistogramma caetei Kullander, 1980 Fr endemic    3.60 cm SL male/unsexed ;4.00 cm female  Known from the Apeú and Caete rivers in Bragança, Pará (Ref. 36377). Type locality: Igarapé in Bragança, Pará, Brazil, 1°45'S, 46°47'W (Ref. 12965). + 
Cichlidae Apistogramma commbrae (Regan, 1906) Fr native  Cará (Portuguese), Acará (Portuguese)   3.30 cm SL male/unsexed ;3.50 cm TL female    + 
Cichlidae Apistogramma diplotaenia Kullander, 1987 Fr native    2.92 cm SL male/unsexed ;4.50 cm TL female  Type locality, est. Amazonas, R., Negro drainage system, , downstream of the R. Daraã, MZUSP 28213 (holotype of Apistogramma diplotaenia, 2.84 cm SL, male) (Ref. 86447). Known from the Amazon River basin, in the middle Negro River (Ref. 36377). Found throughout the Anavilhanas Archipelago in the Rio Negro where fishing is now forbidden (Ref. 12251). + 
Cichlidae Apistogramma eleutheria Varella & Britzke, 2016 Fr native   3.95 cm SL male/unsexed ;4.01 cm SL female  Type locality of Apistogramma eleutheria from Pará, Altamira: rio Xingu basin, rio Iriri drainage, rio Treze de Maio, a tributary of rio Curuá, upstream of PCH Salto Treze de Maio dam; MZUSP 115293 (Ref. 129298). - 
Cichlidae Apistogramma elizabethae Kullander, 1980 Fr native    4.00 cm SL male/unsexed ;3.00 cm female  Known from the Amazon River basin in the Uaupés River basin (Ref. 36377). Type locality: Affluent of Rio Uaupés at Trovao, ca. 20 km from mouth of Uaupés, 0°02'N, 67°26'W, Amazonas State, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Apistogramma erythrura Staeck & Schindler, 2008 Fr introduced    4.34 cm SL male/unsexed    + 
Cichlidae Apistogramma eunotus Kullander, 1981 Fr native   5.30 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36377). + 
Cichlidae Apistogramma flavipedunculata Varella & Britzke, 2016 Fr native   4.55 cm SL male/unsexed  Type locality of Apistogramma flavipedunculata from Pará, Altamira, rio Xingu basin, rio Iriri drainage, rio Escorpião, tributary of the upper rio Curuá, at route BR163 bridge; MZUSP 115292 (Ref. 129298). - 
Cichlidae Apistogramma geisleri Meinken, 1971 Fr native    2.80 cm SL male/unsexed  Known from the Amazon River basin, in the region of the lower Trombetas River basin (Ref. 36377). Belem do Para, near where these fish can be found, was a major fish exporting point in the 1950's and large quantities of these fish were exported but never spawned because the females were separated as another species and these fish were shipped with the females of still another species (Ref. 12251). Type locality: Rio Curuçamba near Obidos, Amazonas, Brazil (Ref. 12965). + 
Cichlidae Apistogramma gephyra Kullander, 1980 Fr endemic    3.30 cm SL male/unsexed ;4.00 cm female  Known from the lower Negro River basin, Amazon River basin (Ref. 36377). Type locality: Rio Igarapé affluent of Rio Negro, Archipel das Anavilhanas, 3°00'S, 60°45'W, Amazonas State, Brazil (Ref. 12965). + 
Cichlidae Apistogramma gibbiceps Meinken, 1969 Fr endemic   4.50 cm SL male/unsexed ;5.00 cm female  Known from Branco and middle Negro River basins in the Amazon River basin (Ref. 36377). Type locality: Rio Negro, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Apistogramma gossei Kullander, 1982 Fr native    4.40 cm SL male/unsexed ;5.00 cm female  Known from the Oyapock River (Ref. 12251, 36377). + 
Cichlidae Apistogramma hippolytae Kullander, 1982 Fr endemic    3.40 cm SL male/unsexed ;5.00 cm female  Known from the Amazon River basin, middle Negro River drainage (near mouths of Urubaxi and Daraã rivers), and Lake Manacapuru (Ref. 36377). Type locality: Igarapé des Lago Manacapuru, Rio Solimoes system, Amazonas, Brazil (Ref. 12965). + 
Cichlidae Apistogramma inconspicua Kullander, 1983 Fr native   3.80 cm SL male/unsexed ;4.00 cm female   + 
Cichlidae Apistogramma juruensis Kullander, 1986 Fr endemic    2.40 cm SL male/unsexed  Known from the upper Juruá River basin, Amazon River basin (Ref. 36377). + 
Cichlidae Apistogramma kullanderi Varella & Sabaj Pérez, 2014 Fr native   7.97 cm SL male/unsexed ;5.87 cm SL female  Found only in the from the upper rio Curuá and two of its larger tributaries on Serra do Cachimbo, an isolated plateau of the Brazilian (Guaporé) Shield (Ref. 98797). + 
Cichlidae Apistogramma linkei Koslowski, 1985 Fr native    3.90 cm SL male/unsexed ;4.00 cm female    + 
Cichlidae Apistogramma meinkeni Kullander, 1980 Fr endemic    3.50 cm SL male/unsexed ;4.50 cm female  Known from the Uaupés River basin of the Amazon River basin (Ref. 36377). Type locality: Affluent of Rio Uaupés at Trovao, ca. 20 km from mouth of Uaupés, 0°02'N, 67°26'W, Amazonas State, Brazil (Ref. 12965). + 
Cichlidae Apistogramma mendezi Römer, 1994 Fr endemic     Known from the Negro River basin of the Amazon River basin (Ref. 36377). Type locality: Small igarapé (forest stream) near airfield of Barcelos do Rio Negro, Dept. Amazonas, Brazil (aprox. 63.04’W/0.01’S), sometimes called "Rio Salgádo" by local people. + 
Cichlidae Apistogramma moae Kullander, 1980 Fr endemic    5.00 cm SL male/unsexed  Known from the Amazon River basin, in the upper Juruá River basin (Ref. 36377). + 
Cichlidae Apistogramma paucisquamis Kullander & Staeck, 1988 Fr endemic   3.40 cm SL male/unsexed  Known from the Amazon River basin, in the middle and lower Negro River from Daraã River to the Anavilhanas Archipelago (Ref. 36377). Type locality: small shallow bay on the right bank of Rio Negro, Anavilhanas Is., MZUSP 36952 (holotype of Apistogramma paucisquamis, 2.97 cm SL, adult male) (Ref. 58483). Also Ref. 12251. + 
Cichlidae Apistogramma personata Kullander, 1980 Fr endemic    5.17 cm SL male/unsexed  Known from the Amazon River basin, in the Uaupés River basin (Ref. 36377). Type locality: Rio Uaupés, Assai, 0°02'N, 67°27'W, Amazonas State, Brazil (Ref. 12251). + 
Cichlidae Apistogramma pertensis (Haseman, 1911) Fr, Or endemic  Pertense (Portuguese)   3.90 cm SL male/unsexed ;4.50 cm TL female  Known from the Amazon River basin, in the lower Negro River and from Manacapuru to Monte Alegre along the Amazon-Solimões River (Ref. 36377). Exported to North America as an aquarium fish (Ref. 4537). + 
Cichlidae Apistogramma piauiensis Kullander, 1980 Fr native    2.30 cm SL male/unsexed  Known from the Parnaíba River basin (Ref. 36377). Type locality: Lagoa Seca, ca. 1 km from camp on Rio Parnaiba at Barra do Longa, near Buriti dos Lopes, Brazil, 3°08'S, 41°54'W (Ref. 12965). Also Ref. 12251. + 
Cichlidae Apistogramma pulchra Kullander, 1980 Fr endemic    3.20 cm SL male/unsexed  Known from the Madeira River basin of the Amazon River basin (Ref. 36377). Type locality: Rio Preto, affluent of Rio Candeias, 25 km from Porto-Velho, Rondonia Terr., Brazil, 8°46'S, 63°45'W (Ref. 12965). Also Ref. 12251. + 
Cichlidae Apistogramma regani Kullander, 1980 Fr endemic  Acarra (Portuguese)   4.90 cm SL male/unsexed ;5.00 cm female  Known from the Amazon River basin, in the lower Negro River basin (Ref. 36377). Type locality: Igarapé affluent of Rio Negro, Archipel das Anavilhanas, 3°00'S, 60°45'W, Amazonas State, Brazil (Ref. 12965). Anavilhanas Archipelago is now a protected area where fishing is prohibited (Ref. 12251). + 
Cichlidae Apistogramma resticulosa Kullander, 1980 Fr endemic    3.87 cm SL male/unsexed  Known from the Amazon River basin, in the Madeira River drainage near Huamitá (Ref. 36377). Type locality: Igarapé Xicanga, ca. 5 km west of Humaitá, 7°31'S, 63°04'W, Rio Madeira drainage system, Amazonas State, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Apistogramma rupununi Fowler, 1914 Fr native    3.80 cm SL male/unsexed ;5.00 cm female  Known from the Branco River of the Amazon River basin (Ref. 36377). + 
Cichlidae Apistogramma salpinction Kullander & Ferreira, 2005 Fr native    3.35 cm SL male/unsexed    - 
Cichlidae Apistogramma sororcula Staeck & Schindler, 2016 Fr native   4.17 cm SL male/unsexed   - 
Cichlidae Apistogramma staecki Koslowski, 1985 Fr native    2.10 cm SL male/unsexed ;4.00 cm female  Known from Mato Grosso (Ref. 12251). + 
Cichlidae Apistogramma taeniata (Günther, 1862) Fr endemic   4.20 cm SL male/unsexed  Known from the Amazon River basin, in the lower Tapajós River basin (Ref. 36377). Type locality: Rio Cupai, 800 mi. from the sea, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Apistogramma trifasciata (Eigenmann & Kennedy, 1903) Fr native    3.80 cm SL male/unsexed ;4.60 cm female  Known from the Amazon River basin in the middle Guaporé drainage and from the Paraná River basin in the Paraguay River drainage (Ref. 36377). Found in Mato Grosso area (Ref. 12251). + 
Cichlidae Apistogramma tucurui Staeck, 2003 Fr native     Known from basin of the lower Rio Tocantins in Pará (Ref. 55839). - 
Cichlidae Apistogramma uaupesi Kullander, 1980 Fr endemic    2.80 cm SL male/unsexed ;6.00 cm TL female  Known from the Amazon River basin in the Uaupés River and nearby Negro River basin (Ref. 36377). Type locality: Affluent of Rio Uaupés at Trovao, ca. 20 km from mouth of Uaupés, 0°02'N, 67°26'W, Amazonas State, Brazil (Ref. 12965). + 
Cichlidae Apistogramma wapisana Römer, Hahn & Conrad, 2006 Fr native   2.80 cm SL male/unsexed ;2.91 cm SL female  Found in north-west Brazi. Known from the drainage of the upper Rio Branco in the vicinity of the town of Boa Vista Caught in flowing waters, specifically the Igarapés luciniu and Agua Boa, and the Rio Cauamé; also in central Rio Negro drainae in the vicinity of Barcellos do Rio Negro (Ref. 57916). - 
Trichomycteridae Apomatoceros alleni Eigenmann, 1922 Fr native    14.60 cm SL male/unsexed   - 
Apteronotidae Apteronotus acidops Triques, 2011 Fr native  Sarapó (Portuguese), Boca rachada (Portuguese)  32.10 cm TL male/unsexed  Known from the upper rio Paraná basin (Ref. 88927). - 
Apteronotidae Apteronotus albifrons (Linnaeus, 1766) Fr native  Itoui cavalo (Portuguese), Ituí cavalo (Portuguese)   50.00 cm TL male/unsexed  Occurs in Paraná, Paraguay (Ref. 4537) and Machado River basins (Ref. 97589). + 
Apteronotidae Apteronotus bonapartii (Castelnau, 1855) Fr native  Sarrapu (Portuguese), Soia (Portuguese)   38.00 cm SL male/unsexed  Found in the Amazon River basin (Ref. 36886). + 
Apteronotidae Apteronotus brasiliensis (Reinhardt, 1852) Fr native  Sarapó (Portuguese)   29.00 cm TL male/unsexed  Found in Das Velhas River basin (Ref. 36886). - 
Apteronotidae Apteronotus camposdapazi de Santana & Lehmann A., 2006 Fr native    Known from the Rio Tocantins basin in Goiás State (Ref. 57702). - 
Apteronotidae Apteronotus caudimaculosus de Santana, 2003 Fr native    28.68 cm TL male/unsexed  Known from the Rio Novo in the middle Rio Negro and from Rio do Peixe in the upper Rio Negro, Paraguay River basin in the state of Mato Grosso do Sul, Pantanal wetland, western Brazil (Ref. 50581). Type locality: Mato Grosso do Sul. AQUARAP Pantanal 19°36.4'S, 56°24.87'W, Aquidauna, Rio Novo, Brejo de Santa Sofia (Ref. 50581). - 
Apteronotidae Apteronotus curvioperculata (Godoy, 1968) Fr native    25.30 cm TL male/unsexed  Known from the Paraná River (Ref. 26457). Also Ref. 36886. - 
Apteronotidae Apteronotus ellisi (Alonso de Arámburu, 1957) Fr questionable    32.80 cm TL male/unsexed  Outside distributional range, occurrence needs confirmation. + 
Apteronotidae Apteronotus leptorhynchus (Ellis, 1912) Fr native   26.90 cm TL male/unsexed   + 
Apteronotidae Apteronotus lindalvae de Santana & Cox Fernandes, 2012 Fr native   33.30 cm TL male/unsexed  Known from the Rio Uatumã, at Cachoeiras (waterfalls) do Mirití and Morena in the Amazon basin (Ref. 91045). + 
Apteronotidae Apteronotus macrolepis (Steindachner, 1881) Fr native   18.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). - 
Arapaimidae Arapaima agassizii (Valenciennes, 1847) Fr native    Found in lowlands of Amazon (Ref. 93668). - 
Arapaimidae Arapaima gigas (Schinz, 1822) Fr, Fi, Rstr native  Bodeco (Portuguese), Pira urucu (Portuguese), Pirarucu (Portuguese), Pirarucú (Portuguese), Pirarucu preto (Portuguese), Pirarucu vermelho (Portuguese), Pirosca (Portuguese)   450 cm TL male/unsexed 120 TL Known from the Amazon River basin (Ref. 50891). Much appreciated food fish. Overfished in 1998. Catch prohibited from November to March (Ref. 27548). Also Ref. 1739. + 
Arapaimidae Arapaima leptosoma Stewart, 2013 Fr native   77.60 cm SL male/unsexed  Known from the Solimões River in Amazonas State (Ref. 94273). - 
Arapaimidae Arapaima mapae (Valenciennes, 1847) Fr native   203 cm SL male/unsexed  Known only from the Lago do Amapá in Amapá State (Ref. 94273). - 
Sternopygidae Archolaemus blax Korringa, 1970 Fr native    43.50 cm TL male/unsexed  Found in the Amazon, Tocantins and Branco River basins and Amapa State (Ref. 39524). + 
Sternopygidae Archolaemus ferreirai Vari, de Santana & Wosiacki, 2012 Fr native   34.20 cm TL male/unsexed  Found in the north-eastern portions of the Amazon basin in the Rio Mucajaí at Cachoeira Paredão 2 and the Rio Uraricoera at Ilha de Maracá, both in Roraima (Ref. 93148). + 
Sternopygidae Archolaemus janeae Vari, de Santana & Wosiacki, 2012 Fr native   40.20 cm TL male/unsexed  Known from the upper and lower portions of the Rio Xingu basin at the Rio Iriri, the Cachoeira de Kaituká at Município de Altamira, and localities in the Rio Culuene, as well as the upper Rio Tapajós basin, where it was collected in the Rio Jamanxim at the Município do Novo Progresso (Ref. 93148). + 
Sternopygidae Archolaemus luciae Vari, de Santana & Wosiacki, 2012 Fr native   49.70 cm TL male/unsexed  Known from the Rio Jari, Rio Trombetas and Rio Tapajós basins in eastern Amazon and Rio Araguari (Ref. 93148). + 
Sternopygidae Archolaemus orientalis Stewart, Vari, de Santana & Wosiacki, 2012 Fr native    Known from the upper Rio São Francisco basin in Minas Gerais (Ref. 93148). + 
Sternopygidae Archolaemus santosi Vari, de Santana & Wosiacki, 2012 Fr native   21.20 cm TL male/unsexed  Known from the Rio Jamari, Amazon basin in Rondônia (Ref. 93148). + 
Hemiodontidae Argonectes longiceps (Kner, 1858) Fr native  Jatuarana (Portuguese), O-Oií-Apotira (Portuguese), Uiarana (Portuguese), Voador (Portuguese), Voador americano (Portuguese)   26.00 cm SL male/unsexed  Type locality: Icanno, Brazil (Ref. 12965). + 
Hemiodontidae Argonectes robertsi Langeani, 1999 Fr native  Jatuarana (Portuguese), Uiarana (Portuguese)   35.50 cm TL male/unsexed  Known from Tapajós, Xingu, Tocantins, and Capim River basins (Ref. 38289). + 
Callichthyidae Aspidoras albater Nijssen & Isbrücker, 1976 Fr native   3.56 cm SL male/unsexed  Known from the Rio Tocantins and its tributaries (Ref. 26041). Also Ref. 37395. - 
Callichthyidae Aspidoras belenos Britto, 1998 Fr native   2.79 cm SL male/unsexed  Known only from Rio das Mortes basin, Araguaia river system. Museum: Estado do Mato Grosso, creek at Primavera do Leste, MNRJ 12433 (holotype, 27.8 mm SL, female) (Ref. 30407). Also Ref. 37395, 44774. - 
Callichthyidae Aspidoras brunneus Nijssen & Isbrücker, 1976 Fr native   2.13 cm SL male/unsexed  Known from the upper Araguaia River basin (Ref. 37395). Found in Serra do Roncador, Mato Grosso (Ref. 26041); rio Xingú system (Ref. 44774). - 
Callichthyidae Aspidoras carvalhoi Nijssen & Isbrücker, 1976 Fr native   2.54 cm SL male/unsexed  Recorded from Acude Canabrava in Guaramiranga, Ceara (Ref. 26041). Also Ref. 37395. - 
Callichthyidae Aspidoras depinnai Britto, 2000 Fr native    3.25 cm SL male/unsexed  Known from the Ipojuca River basin (Ref. 37395). Type locality, rio Ipojuca basin (an isolated NE coastal drainage), creek at Amaraji-Primavera road, Pernambuco State (Ref. 44774). + 
Callichthyidae Aspidoras eurycephalus Nijssen & Isbrücker, 1976 Fr native   3.00 cm SL male/unsexed  Known from the upper Tocantins River basin (Ref. 37395). Recorded from Corrego Vermelho in Rio das Almas, a tributary of the Rio Maranhao, Estado Goias (Ref. 26041). + 
Callichthyidae Aspidoras fuscoguttatus Nijssen & Isbrücker, 1976 Fr native    3.80 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 37395). Recorded from Corrego Corguinho, Estradas da Tres Lagoas, Mato Grosso (Ref. 26041). Also Ref. 37395. + 
Callichthyidae Aspidoras gabrieli Wosiacki, Graças Pereira & Reis, 2014 Fr native   3.66 cm SL male/unsexed  Found in streams draining the Serra dos Carajás, Paraupebas, Pará, at the type locality and nearby points, in unnamed tributaries to the left bank of Rio Paraupebas, itself a tributary to the Rio Itacaiúnas, lower Rio Tocantins basin. Occurs in the lower portion of the Rio Tocantins basin, at the edge of the Brazilian Shield into the Amazon basin (Ref. 96502). - 
Callichthyidae Aspidoras kiriri Oliveira, Zanata, Tencatt & Britto, 2017 Fr native   3.34 cm SL male/unsexed  Type locality of Aspidoras kiriri from Bahia, Varzedo, riacho Cai-Camarão, rio da Dona basin; MNRJ 47400 (Ref. 129224). - 
Callichthyidae Aspidoras lakoi Miranda Ribeiro, 1949 Fr native    4.00 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 37395). Recorded from Fazenda da Cachoeira, Minas Gerais (Ref. 26041). + 
Callichthyidae Aspidoras maculosus Nijssen & Isbrücker, 1976 Fr native   3.37 cm SL male/unsexed  Found in the Rio Paiaia which flows into the headwaters of the Rio Itapicuru in Bahia (Ref. 26041). Also Ref. 37395. - 
Callichthyidae Aspidoras marianae Leão, Britto & Wosiacki, 2015 Fr endemic    2.85 cm SL male/unsexed  Known only from its type locality, an unnamed stream tributary of the Rio Curuá, itself a tributary of the Rio Iriri, in the Rio Xingu basin (Ref. 114781). - 
Callichthyidae Aspidoras menezesi Nijssen & Isbrücker, 1976 Fr native   4.18 cm SL male/unsexed  Found in coastal rivers in Ceará (Ref. 37395). Recorded from the Rio Granjeiro at Crato, Estado Goias (Ref. 26041). + 
Callichthyidae Aspidoras microgalaeus Britto, 1998 Fr native   3.32 cm SL male/unsexed  Known from rio Xingú basin (Ref. 30407). Museum: Estado do Mato Grosso, small tributary of rio Culuene, km 86 of Paranatinga- Canarana road, rio Xingú basin, MZUSP 51209 (holotype, female, 25.7 mm SL) (Ref. 30407). Also Ref. 37395, 44774. - 
Callichthyidae Aspidoras pauciradiatus (Weitzman & Nijssen, 1970) Fr, Or native   2.90 cm SL male/unsexed  Recorded from Rio Araguaia at Aruana and Rio Negro (Ref. 26041). Also Ref. 37395, 44774. + 
Callichthyidae Aspidoras poecilus Nijssen & Isbrücker, 1976 Fr native   3.53 cm SL male/unsexed  Found in the upper Xingu, Araguaia, and Tocantins River basin (Ref. 37395). Recorded from the Rio Xingu in Mato Grosso (Ref. 26041). + 
Callichthyidae Aspidoras psammatides Britto, Lima & Santos, 2005 Fr native   3.10 cm SL male/unsexed  Known from tributaries of the upper rio Paraguaçu, a coastal river basin from eastern Brazil (Ref. 57143). - 
Callichthyidae Aspidoras raimundi (Steindachner, 1907) Fr native    3.26 cm SL male/unsexed  Known from the Parnaíba River basin (Ref. 37395). Also Ref. 26041. + 
Callichthyidae Aspidoras rochai Ihering, 1907 Fr native  Comboeiro (Portuguese), Dunda (Portuguese)  4.42 cm SL male/unsexed  Found in Fortaleza, Estado Ceara (Ref. 26041). Also Ref. 37395. - 
Callichthyidae Aspidoras spilotus Nijssen & Isbrücker, 1976 Fr native   4.32 cm SL male/unsexed  Found in Riacho dos Macacos, a tributary of the Rio Acarau, Estado Ceara (Ref. 26041). Also Ref. 37395. + 
Callichthyidae Aspidoras taurus Lima & Britto, 2001 Fr native   5.41 cm SL male/unsexed ;5.21 cm SL female  Type locality, rio Paraguai system, rio Itiquira, close to highway BR-364, Fazenda Cabeceira do Itiquira, município de Alto Garças. Known from the upper rio Itiquira and upper rio Taquari, both are tributaries of the rio Paraguai, Mato Grosso State (Ref. 41106). + 
Callichthyidae Aspidoras velites Britto, Lima & Moreira, 2002 Fr native   2.79 cm SL male/unsexed  Found in small tributaries of the upper Araguaia River in Mato Grosso State (Ref. 37395). - 
Callichthyidae Aspidoras virgulatus Nijssen & Isbrücker, 1980 Fr native    3.61 cm SL male/unsexed  Known from the upper Parnahyba, Estado Maranhao (Ref. 26041). - 
Ariidae Aspistor luniscutis (Valenciennes, 1840) Fr, Br, M native  Bagre amarelo (Portuguese), Bagre caiacoco (Portuguese), Bagre cangatá (Portuguese), Bagre guri (Portuguese), Bagre gurí (Portuguese), Bagre-amarelo (Portuguese), Bagre-de-areia (Portuguese), Caiacoco (Portuguese), Canagatá (Portuguese), Cangatá (Portuguese), Cangatã (Portuguese), Cangatá-í (Portuguese), Cangatã-í (Portuguese), Garajuba (Portuguese), Gorujuba (Portuguese), Griujuba (Portuguese), Grui-juba (Portuguese), Gruijuba (Portuguese), Guarijuba (Portuguese), Guorijuba (Portuguese), Guri-açu (Portuguese), Gurí-açu (Portuguese), Gurí-açú (Portuguese), Guri-juba (Portuguese), Gurí-juba (Portuguese), Guriaçu (Portuguese), Guribu (Portuguese), Gurijuba (Portuguese), Gurujuba (Portuguese), Gurujuva (Portuguese), Iriceca (Portuguese), Irideca (Portuguese), Jurupiranga (Portuguese), Tanajuba (Portuguese), Tanajura (Portuguese), Urí (Portuguese)  120 cm TL male/unsexed 18 TL Also Ref. 58022. + 
Ariidae Aspistor quadriscutis (Valenciennes, 1840) Fr, Br, M native  Bagre (Portuguese), Cangatá (Portuguese), Cangatã (Portuguese)  50.00 cm TL male/unsexed   + 
Aspredinidae Aspredinichthys filamentosus (Valenciennes, 1840) Fr, Br native   21.80 cm SL male/unsexed  Occurs in northern Brazil (Ref. 5266). + 
Aspredinidae Aspredinichthys tibicen (Valenciennes, 1840) Fr, Br native  Viola (Portuguese)  24.30 cm TL male/unsexed   + 
Aspredinidae Aspredo aspredo (Linnaeus, 1758) Fr, Br native  Viola (Portuguese)   38.30 cm SL male/unsexed    + 
Auchenipteridae Asterophysus batrachus Kner, 1858 Fr native  Mamyacú (Portuguese), Mamyeacú (Portuguese)  25.00 cm SL male/unsexed  Found in Marabitanos (Ref. 6868). + 
Doradidae Astrodoras asterifrons (Kner, 1853) Fr native   12.50 cm SL male/unsexed  Known from the Amazon River, Jutahy, Teffé, Manaus, Porto do Moz, Serpa, Santarém, Maciél, Guaporé River, San Joaquín and Cupai River (Ref. 37054). Also Ref. 85809. + 
Cichlidae Astronotus crassipinnis (Heckel, 1840) Fr, Fi native  Acará açu (Portuguese), Acará-açu (Portuguese), Apaiari (Portuguese), Cará-açu (Portuguese)   24.00 cm SL male/unsexed  Type locality of Astronotus crassipinnis, R. Paraguay, Villa Maria and Caiçara, R. Guapore near Matogrosso, Rio Negro, Rio Branco. Known from the Paraná River basin in the Paraguay drainage (Ref. 36377). Introduced in Bahia and São Paulo states and the upper Paraná River in Brazil (Ref. 126783). Found in fish markets in Santarém (Ref. 12202). + 
Cichlidae Astronotus ocellatus (Agassiz, 1831) Fr, Fi native  Corró-baiano (Portuguese), Acará-açu (Portuguese), Acará-grande (Portuguese), Acaraú-açu (Portuguese), Acaráuaçu (Portuguese), Apaiari (Portuguese), Apiari (Portuguese), Bola-de-ouro (Portuguese), Cará (Portuguese), Cará pirosca (Portuguese), Cará-açu (Portuguese), Cará-boi (Portuguese), Cará-grande (Portuguese), Corró-chinês (Portuguese), Dorminhoco (Portuguese) scarce (very unlikely) 45.70 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36377). Recorded in Piracicaba river (Ref. 50076). Considered economically important by the Brazilians who have acclimated the originally Amazonian stocks to the conditions of the province in the northeast (Ref. 27188). Established populations introduced in the states of Bahia, Ceará, Espirito Santo, Maranhão, and Piauí (Ref. 126783). + 
Characidae Astyanax abramis (Jenyns, 1842) Fr native  Acará-pixuma (Portuguese), Acará pixuna (Portuguese), Lambari (Portuguese)   14.00 cm SL male/unsexed    + 
Characidae Astyanax altiparanae Garutti & Britski, 2000 Fr native    16.40 cm TL male/unsexed 3.65 Known from the upper Paraná River basin (Ref. 53011). Recorded from the rio Iguaçu basin (Ref. 81203). + 
Characidae Astyanax argyrimarginatus Garutti, 1999 Fr native   4.53 cm SL male/unsexed  Found in the Amazon River basin (Ref. 38376). + 
Characidae Astyanax asuncionensis Géry, 1972 Fr native  Lambari (Portuguese)   15.00 cm SL male/unsexed    + 
Characidae Astyanax bagual Bertaco & Vigo, 2015 Fr native   7.84 cm SL male/unsexed  Found in the rio Taquari- Antas basin, rio Jacuí drainage, laguna dos Patos system, Rio Grande do Sul State. Appears to inhabit only in rivers from mid-slope valleys and in the plateau sections of the Taquari-Antas basin (Ref. 103251). Status of threat: Least concern (LC) as there is no imminent known threats to the species (Ref. 103251). - 
Characidae Astyanax bimaculatus (Linnaeus, 1758) Fr, Br, Fi native  Machadinha (Portuguese), Lambari (Portuguese), Lambari do rabo amarelo (Portuguese), Matupiri (Portuguese), Piaba (Portuguese), Piaba chata (Portuguese), Piaba do rabo amarelo (Portuguese), Piaba-rabo-amarelo (Portuguese), Piava chata (Portuguese), Tambiú (Portuguese) scarce (very unlikely) 17.50 cm TL male/unsexed  Recorded from Pardo River (Ref. 27745), Caracu and Sao Pedro streams, tributaries of the Paraná river; Pircacicaba river (Ref. 50076), Rio Jurúa (lakes and tributaries) (MZUSP No. 50281, Ref. 42843) and the Patos lagoon (Ref. 58359). Found in the Uruguay (Ref. 79585) and Acre River basins (Ref. 97592). Also Ref. 31923. + 
Characidae Astyanax biotae Castro & Vari, 2004 Fr native    5.20 cm SL male/unsexed  Known from Rio Paranapanema basin, upper Rio Paraná system in southeastern Brazil (Ref. 55832). - 
Characidae Astyanax bourgeti Eigenmann, 1908 Fr native    Known from the Amazon River basin (Ref. 38376). Type locality: Tabatinga, Amazonas, Brazil (Ref. 26282). - 
Characidae Astyanax brachypterygium Bertaco & Malabarba, 2001 Fr native   6.42 cm SL male/unsexed  Known from the uppermost headwaters of tributaries of the rio Uruguai, at altitudes of 1000 to 1200 m asl, in the highest portions of the Serra Geral, in Rio Grande do Sul (Ref. 41290). - 
Characidae Astyanax brevirhinus Eigenmann, 1908 Fr native   10.00 cm TL male/unsexed  Found in the Jequitinhonha River basin (Ref. 38376). - 
Characidae Astyanax brucutu Zanata, Lima, Di Dario & Gerhard, 2017 Fr native   6.57 cm SL male/unsexed  Type locality of Astyanax brucutu from rio Paraguaçu basin, tributary of rio Santo Antônio, Fazenda Pratinha, rio Pratinha, Iraquara, Bahia; ZUEC 12765 (Ref. 117444). - 
Characidae Astyanax clavitaeniatus Garutti, 2003 Fr native   7.24 cm SL male/unsexed  Known from rio Branco, affluent of rio Negro, Amazon basin (Ref. 55833). - 
Characidae Astyanax courensis Bertaco, Carvalho & Jerep, 2010 Fr native   7.16 cm SL male/unsexed  Type locality, rio dos Couros at Parque Portal da Chapada, tributary of rio Tocantinzinho, upper rio Tocantins basin, 1135 m a.s.l, Alto Paraíso de Goiás, Goiás State, UFRGS 11499 (holotype of Astyanax courensis, 5.42 cm SL, female) (Ref. 84461). - 
Characidae Astyanax cremnobates Bertaco & Malabarba, 2001 Fr endemic   8.91 cm SL male/unsexed  Known from the uppermost headwaters of the rio Jacuí and rio Maquiné, Rio Grande do Sul (Ref. 41290). - 
Characidae Astyanax depressirostris Miranda Ribeiro, 1908 Fr native    Known from Ribeira River, São Paulo (Ref. 38376). - 
Characidae Astyanax dissimilis Garavello & Sampaio, 2010 Fr native    13.58 cm SL male/unsexed  Rio Canoinhas, tributary of Rio Iguaçu near the bridge on highway BR 280 from Mafra to Itaiópolis, Canoinhas, Santa Catarina, MZUSP 105969 (holotype of Astyanax dissimilis, 6.28 cm Sl, male). It is known only from Iguaçu basin with wide distribution (Ref. 85756). - 
Characidae Astyanax dnophos Lima & Zuanon, 2004 Fr native   3.32 cm SL male/unsexed  Known from the lower rio Xingu in Pará (Ref. 55826). - 
Characidae Astyanax douradilho Bertaco, 2014 Fr native   9.00 cm SL male/unsexed  Found in the tributaries of the rio Maquiné, rio Tramandaí system, coastal drainage of Rio Grande do Sul, southern Brazil (Ref. 96006). - 
Characidae Astyanax elachylepis Bertaco & Lucinda, 2005 Fr native    Known from the rio Tocantins drainage (Ref. 56789). - 
Characidae Astyanax epiagos Zanata & Camelier, 2008 Fr native   5.93 cm SL male/unsexed   - 
Characidae Astyanax eremus Ingenito & Duboc, 2014 Fr native   9.95 cm SL male/unsexed 6.18 SL Known from the rio Canivete, a small and short isolated affluent of the upper rio Iguaçu, a tributary to the rio Paraná drainage (Ref. 96865). - 
Characidae Astyanax goyacensis Eigenmann, 1908 Fr native    Known from Goyaz. + 
Characidae Astyanax goyanensis (Miranda Ribeiro, 1944) Fr native   9.00 cm SL male/unsexed  Type locality, Goiás State, rio dos Couros, Chapada dos Veadeiros, MNRJ 4129 (holotype of Astyanacinus goyanensis, 8.22 cm SL, female) (Ref. 84461). - 
Characidae Astyanax gracilior Eigenmann, 1908 Fr native    Found in the Amazon River basin (Ref. 38376). Type locality: Obidos and Villa Bella, Brazil (Ref. 26282). - 
Characidae Astyanax guaricana Oliveira, Abilhoa & Pavanelli, 2013 Fr native   9.56 cm SL male/unsexed  Found in the tributaries of the rio Cubatão, coastal basin of Paraná State (Ref. 93808). - 
Characidae Astyanax henseli de Melo & Buckup, 2006 Fr native   11.10 cm SL male/unsexed 6.9 SL Type locality, Porto Alegre, Rio Grande do Sul, ZMB 7479 (holotype of Tetragonopterus aeneus Hensel 1870, male, 7.8 cm SL). Known from the rio dos Sinos and rio Taquari drainages in Southern Brazil. Both rivers are tributaries of the lago Guaíba which is located next to the city of Porto Alegre, and is the northernmost component of the laguna dos Patos system (Ref. 56653). - 
Characidae Astyanax jacobinae Zanata & Camelier, 2008 Fr native  Piaba (Portuguese)  5.08 cm SL male/unsexed   - 
Characidae Astyanax jacuhiensis (Cope, 1894) Fr native  Lambari do rabo amarelo (Portuguese)  14.48 cm SL male/unsexed  Type locality, Jacuhy, Rio Grande do Sul, ANSP 21912 (lectotype) (Ref. 38376). + 
Characidae Astyanax jenynsii (Steindachner, 1877) Fr native   7.62 cm SL male/unsexed   - 
Characidae Astyanax joaovitori Oliveira, Pavanelli & Bertaco, 2017 Fr native   7.70 cm SL male/unsexed  Found only in the upper rio Araguaia and some tributaries, Mato Grosso State (Ref. 116165). - 
Characidae Astyanax jordanensis Vera Alcaraz, Pavanelli & Bertaco, 2009 Fr native    7.61 cm SL male/unsexed  Known from the middle and upper portions of rio Jacu and rio das Torres in the lower portions of the rio Jordão drainage, lower rio Iguaçu basin in Paraná (Ref. 81203). - 
Characidae Astyanax keronolepis Silva, Malabarba & Malabarba, 2019 Fr native   10.39 cm SL male/unsexed  Occurs in coastal streams from Ubatuba in São Paulo State to Guapimirim River basin in Rio de Janeiro State (Ref. 119398) - 
Characidae Astyanax kullanderi Costa, 1995 Fr native   8.80 cm SL male/unsexed  Museum: Estado de Mato Grosso, stream tributary of rio Perdidos, rio das Mortes drainage, MZUSP 45288 (Ref. 27925). - 
Characidae Astyanax lacustris (Lütken, 1875) Fr native  Tambiú (Portuguese)   9.30 cm SL male/unsexed 3.066 SL Recorded from Trés Marias Dam - MG - São Francisco River (Ref. 85131). + 
Characidae Astyanax laticeps (Cope, 1894) Fr native    8.90 cm SL male/unsexed  Type locality, Rio Grande do Sul (Ref. 54621). - 
Characidae Astyanax leopoldi Géry, Planquette & Le Bail, 1988 Fr native   6.00 cm TL male/unsexed  Present in the Oyapock River which forms the border between French Guiana and Brazil (Ref. 12225). + 
Characidae Astyanax lineatus (Perugia, 1891) Fr native   12.00 cm SL male/unsexed   + 
Characidae Astyanax longirhinus Garavello & Sampaio, 2010 Fr native    18.60 cm SL male/unsexed  Type locality, Rio Iguaçu downstream of Salto Santiago dam, between Laranjeiras do Sul and Chopinzinho, Laranjeiras do Sul, Paraná, MZUSP 105954 (holotype of Astyanax longirhinus, 15.69 cm SL). Known only from medium and lower Iguaçu Basin (Ref. 85756). - 
Characidae Astyanax lorien Zanata, Burger & Camelier, 2018 Fr native   7.54 cm SL male/unsexed  Type locality of Astyanax lorien from Bahia State, Lençóis, Chapada Diamantina, stream tributary of rio Mucugezinho, itself a tributary of rio Santo Antônio, rio Paraguaçu basin; MZUSP 123398 (Ref. 129195). - 
Characidae Astyanax maculisquamis Garutti & Britski, 1997 Fr native   7.64 cm SL male/unsexed  Found in the upper Guaporé (Ref. 38376) and Machado River basin (Ref. 38376). - 
Characidae Astyanax microschemos Bertaco & Lucena, 2006 Fr native   5.51 cm SL male/unsexed  Type locality, Espírito Santo, Iúna, rio Itapemirim drainage, córrego Palmital. MCP 37569 (holotype of Astyanax microschemos, 5.51 cm SL). Found only in the upper most headwaters of the rio Itapemirim drainage, a coastal drainage in Espirito Santo State, eastern Brazil (Ref. 57404). - 
Characidae Astyanax minor Garavello & Sampaio, 2010 Fr native    10.82 cm SL male/unsexed  Known only from upper Iguaçu basin, found mostly in localities situated upstream of confluence with Rio Jordão. Type locality, Rio Iguaçu downstream of Salto Santiago dam, between Laranjeiras do Sul and Chopinzinho, Laranjeiras do Sul, Paraná, MZUSP 105954 (holotype of Astyanax longirhinus, 15.69 cm SL) (Ref. 85756). - 
Characidae Astyanax moorii (Boulenger, 1892) Fr native   10.00 cm SL male/unsexed  Also Ref. 598. - 
Characidae Astyanax nobre Dagosta & Marinho, 2022 Fr native   3.02 cm SL male/unsexed  Type locality of the holotype of Astyanax nobre: tributary of rio Cuiabá, rio Paraguai basin, Municipality of Nobres, Mato Groso State (Ref. 128856). - 
Characidae Astyanax novae Eigenmann, 1911 Fr native    3.31 cm SL male/unsexed  Known from rio Tocantins basin, Estreito, Maranhão (Ref. 96859). - 
Characidae Astyanax obscurus (Hensel, 1870) Fr native    Found in the Laguna dos Patos drainage (Ref. 38376). - 
Characidae Astyanax paranahybae Eigenmann, 1911 Fr native    Found in the Paraná River basin (Ref. 38376). Type locality: Rio Paranahyba, Brazil (Ref. 26282). - 
Characidae Astyanax pardensis Salgado, 2021 Fr native   6.25 cm SL male/unsexed  Type locality of Astyanax pardensis, Bahia, Camacan, Pardo river drainage, tributary of the Panelão river, Panelinha river. Occurs in the Das Contas and Pardo river basins (Ref. 126164). - 
Characidae Astyanax pedri (Eigenmann, 1908) Fr native  Lambari (Portuguese)   7.80 cm SL male/unsexed  Known from the Santo Antônio River basin in the upper Doce River drainage (Ref. 48602). Recorded from Mina Gerais R(ef. 598). - 
Characidae Astyanax pirabitira Lucena, Bertaco & Berbigier, 2013 Fr native   9.09 cm SL male/unsexed  Found in the upper rio das Antas drainage, laguna dos Patos system, and upper rio Pelotas basin, rio Uruguay drainage in southern Brazil (Ref. 94017). - 
Characidae Astyanax pirapuan Tagliacollo, Britzke, Silva & Benine, 2011 Fr native    Found in the tributaries of the Rio Aricá-Mirim, Rio Cuiabá basin in Chapada dos Guimarães, Mato Grosso State (Ref. 86404). - 
Characidae Astyanax poetzschkei Ahl, 1932 Fr native     - 
Characidae Astyanax procerus Lucena, Castro & Bertaco, 2013 Fr native   11.85 cm SL male/unsexed  Found in the upper and middle rio Taquari-Antas and rio Jacuí, laguna dos Patos system in Rio Grande do Sul (Ref. 94153). - 
Characidae Astyanax rupestris Zanata, Burger & Camelier, 2018 Fr native   8.68 cm SL male/unsexed  Type locality from Astyanax rupestris from Bahia State, Chapada Diamantina, Andaraí, Igatu, rio Coisa Boa, tributary of rio Piabas, Rio Paraguaçu basin; MZUSP 89567 (Ref. 129195). - 
Characidae Astyanax saltor Travassos, 1960 Fr native   5.90 cm SL male/unsexed   - 
Characidae Astyanax scabripinnis (Jenyns, 1842) Fr native  Piaba (Portuguese), Piaba dos pirangueiros (Portuguese), Piaba sulana (Portuguese)   15.60 cm TL male/unsexed  Recorded from Pardo River (Ref. 27745), Caracu and Sao Pedro streams, tributaries of the Paraná river. + 
Characidae Astyanax serratus Garavello & Sampaio, 2010 Fr native    12.00 cm SL male/unsexed  Type locality, Rio da Várzea, Agudos do Sul, Paraná, MHNCI 12346 (holotype of Astyanax serratus, 8.6 cm SL). This is known only from Rio Iguaçu where it is widely distributed (Ref. 85756). - 
Characidae Astyanax sincora Burger, Carvalho & Zanata, 2019 Fr native   6.15 cm SL male/unsexed  Type locality of Astyanax sincora from Bahia State, Chapada Diamantina, Mucugê, Fazenda Tremedal, córrego Tremedal, tributary of rio Paraguaçu; MZUSP 120747 (Ref. 120347). - 
Characidae Astyanax stilbe (Cope, 1870) Fr native    Found in the Amazon River basin (Ref. 38376). Type locality: Pará. - 
Characidae Astyanax symmetricus Eigenmann, 1908 Fr native    Found in the Amazon River basin (Ref. 38376). Type locality: Rio Solimões at Tabatinga, Amazonas, Brazil (Ref. 26282). + 
Characidae Astyanax totae Ferreira Haluch & Abilhoa, 2005 Fr native   8.19 cm SL male/unsexed  Known only from rio Cascata, tributary of rio Tortuoso, an affluent of the rio Iguaçu basin in Paraná State (Ref. 56783). - 
Characidae Astyanax trierythropterus Godoy, 1970 Fr native  Lambari de nadadeiras vermelhas (Portuguese)    Found in the upper Paraná River basin (Ref. 38376). Type locality: Cachoeira de Emas, Rio Mogi Guassu, Upper Rio Paraná basin, São Paulo State, Brazil (Ref. 26282). - 
Characidae Astyanax turmalinensis Triques, Vono & Caiafa, 2003 Fr native    6.48 cm SL male/unsexed  Known from the Rio Jequitinhonha basin in Minas Gerais (Ref. 52302). Also reported in São Francisco and the Doce river basins in Parque Nacional da Serra do Cipó (Ref. 85857). Also Ref. 81202. + 
Characidae Astyanax unitaeniatus Garutti, 1998 Fr native    Found in Paraná River basin in the upper Tocantins River drainage (Ref. 38376). - 
Characidae Astyanax utiariti Bertaco & Garutti, 2007 Fr native   7.93 cm SL male/unsexed  Found only in rio Papagaio, a tributary of the upper rio Juruena, upper rio Tapajós drainage in Mato Grosso (Ref. 75035). - 
Characidae Astyanax varii Zanata, Burger, Vita & Camelier, 2019 Fr native   4.43 cm SL male/unsexed  Type locality of Astyanax varii from near the road BR-330, lower rio de Contas Basin, rio Corico in Fazenda Progresso, Ubaitaba, Bahia; MZUSP 121062 (Ref. 129191). - 
Characidae Astyanax varzeae Abilhoa & Duboc, 2007 Fr native   8.31 cm SL male/unsexed  Found only in the rio da Várzea headwaters, an affluent of rio Negro, a tributary of the upper portions of the rio Iguaçu in Paraná State (Ref. 72395). - 
Characidae Astyanax vermilion Zanata & Camelier, 2009 Fr native    4.28 cm SL male/unsexed  Found in rio Salgado, a tributary of rio Cachoeira, and in rio Almada in eastern Brazil. + 
Rivulidae Atlantirivulus depressus (Costa, 1991) Fr endemic   6.50 cm TL male/unsexed   - 
Rivulidae Atlantirivulus guanabarensis Costa, 2014 Fr native   3.53 cm SL male/unsexed ;3.14 cm SL female  Known from various river drainages flowing into the Guanabara bay, and adjacent coastal plains to west, including the Jacarepaguá lagoon system, Rio de Janeiro state, south-eastern Brazil (Ref. 102354). - 
Rivulidae Atlantirivulus haraldsiolii (Berkenkamp, 1984) Fr endemic   5.00 cm TL male/unsexed   + 
Rivulidae Atlantirivulus janeiroensis (Costa, 1991) Fr endemic   6.50 cm TL male/unsexed   + 
Rivulidae Atlantirivulus jurubatibensis (Costa, 2008) Fr native   2.57 cm SL male/unsexed ;2.56 cm SL female 1.8 SL Type locality, freshwater swampy coastal area close to Lagoa do Pires, about 100 m from the beach, in the Parque Nacional de Jurubatiba, Município de Quissamã, Estado do Rio de Janeiro, UFRJ 6611 (holotype of Rivulus jurubatibensis, 2.37 cm SL, male) (Ref. 78703). - 
Rivulidae Atlantirivulus lazzarotoi (Costa, 2007) Fr native    Known from Jurumirim River basin in southeastern Brazil (Ref. 58743). - 
Rivulidae Atlantirivulus luelingi (Seegers, 1984) Fr endemic   5.00 cm TL male/unsexed   + 
Rivulidae Atlantirivulus maricensis Costa, 2014 Fr, Thr native   3.80 cm SL male/unsexed  Found only in the river drainages connected to the Maricá lagoon system, Rio de Janeiro state, southeastern Brazil. Collected first in December 1980 in the Itapeteiú creek, near the point where it flows into the Ubatiba river. In recent years, the area between the Itapeteiú creek and Ubatiba river underwent heavy modification by intense stream bottom sediment extraction and stream bank deforestation, making most fish species of the area extinct. Considered a critically endangered species (Ref. 102354). - 
Rivulidae Atlantirivulus nudiventris (Costa & Brasil, 1991) Fr endemic   4.50 cm TL male/unsexed  Known from the Itapemerim River floodplains (Ref. 36579). Also Ref. 27139. - 
Rivulidae Atlantirivulus paranaguensis Costa, 2014 Fr native   4.39 cm SL male/unsexed ;3.58 cm SL female  Found in small river basins flowing into the Paranaguá bay (Ref. 102354). - 
Rivulidae Atlantirivulus ribeirensis Costa, 2014 Fr native   2.88 cm SL male/unsexed ;3.38 cm SL female  Found in shallow streams, 10 cm deep or less, within or close to dense forests of the Ribeira de Iguape river basin (Ref. 102354). - 
Rivulidae Atlantirivulus riograndensis (Costa & Lanés, 2009) Fr native    3.39 cm SL male/unsexed  Known from the Patos lagoon basin and adjacent coastal plains in southern (Ref. 81223). - 
Rivulidae Atlantirivulus santensis (Köhler, 1906) Fr endemic  Rívulo (Portuguese)  6.50 cm TL male/unsexed   + 
Rivulidae Atlantirivulus simplicis (Costa, 2004) Fr native   3.46 cm SL male/unsexed  Known from Parati, coastal plains of southeastern Brazil (Ref. 55777). Type locality, Swamp near Jabaquara beach, 23°12'26.7"S, 44°43'12.9"W, Parati, Estado do Rio de Janeiro, elev. 23 m (Ref. 54621). - 
Rivulidae Atlantirivulus unaensis (Costa & De Luca, 2009) Fr native    Known from Una, Bahia in eastern Brazil (Ref. 81222). - 
Characidae Atopomesus pachyodus Myers, 1927 Fr native   4.30 cm male/unsexed  Found in the Negro River basin (Ref. 38376). - 
Auchenipteridae Auchenipterichthys longimanus (Günther, 1864) Fr native    22.80 cm TL male/unsexed  Known from the Amazon River basin. Type locality, River Capim, Pará (Ref. 37098). Also Ref. 6868. - 
Auchenipteridae Auchenipterichthys punctatus (Valenciennes, 1840) Fr native  Carawatouí (Portuguese)  15.10 cm SL male/unsexed  Known frm the central parts of the Amazon basin in Brazil. Most specimens were taken from Rio Negro and its tributaries (Ref. 26666). - 
Auchenipteridae Auchenipterichthys thoracatus (Kner, 1858) Fr native    13.80 cm SL male/unsexed    + 
Auchenipteridae Auchenipterus ambyiacus Fowler, 1915 Fr native    24.40 cm SL male/unsexed    + 
Auchenipteridae Auchenipterus brachyurus (Cope, 1878) Fr native    16.50 cm SL male/unsexed  Known from the Amazon River (Ref. 37098). - 
Auchenipteridae Auchenipterus britskii Ferraris & Vari, 1999 Fr native    15.70 cm SL male/unsexed  Known from the Amazon River (Ref. 37098). Museum: Lago Janauacá, vicinity of Rio Solimões (approx. 3°28'S, 60°17'W), Amazonas, MZUSP 48358 (Ref. 35558). - 
Auchenipteridae Auchenipterus fordicei Eigenmann & Eigenmann, 1888 Fr native   9.90 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37098). - 
Auchenipteridae Auchenipterus menezesi Ferraris & Vari, 1999 Fr native  Peixe-gato (Portuguese)   13.10 cm SL male/unsexed  Known from Parnaíba and Pindaré-Mirim River basins of Maranhão and Piaui States (Ref. 37098). Museum: Lago de Viana, Rio Pindaré. Mirim basin, Maranhão, MZUSP 43591 (Ref. 35558). + 
Auchenipteridae Auchenipterus nigripinnis (Boulenger, 1895) Fr native  Hocicón (Portuguese), Bagre-sapo (Portuguese), Palmitinho (Portuguese), Palmito (Portuguese)   20.20 cm SL male/unsexed    - 
Auchenipteridae Auchenipterus nuchalis (Spix & Agassiz, 1829) Fr, Fi native  Mandi peruano (Portuguese), Carataí (Portuguese), Gato (Portuguese), Lustrosa (Portuguese), Lustrosa de lago (Portuguese), Luz-baixa (Portuguese), Mampará legítimo (Portuguese), Mandi (Portuguese), Mandí sardinha (Portuguese), Mandubi (Portuguese), Mantegueiro (Portuguese), Mapará (Portuguese), Olho-de-gato (Portuguese), Peixe-gato (Portuguese), Surumanha (Portuguese) common (usually seen) 27.00 cm SL male/unsexed  Common in the lower courses of large rivers (Ref. 6868). Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). Found in fish markets in Santarém (Ref. 12202). + 
Auchenipteridae Auchenipterus osteomystax (Miranda Ribeiro, 1918) Fr native  Palmitinho (Portuguese)   39.00 cm TL male/unsexed ;43.00 cm TL female 14.7 TL   + 
Cichlidae Australoheros acaroides (Hensel, 1870) Fr native   12.01 cm SL male/unsexed   - 
Cichlidae Australoheros angiru Říčan, Piálek, Almirón & Casciotta, 2011 Fr native    7.70 cm SL male/unsexed  Type locality, Santa Catarina State, rio Uruguai drainage, rio Jacutinga, road BR 283 from Ceará to Concordia, MCP 13937 (holotype of Australoheros angiru, 7.32 cm SL). Has a disjunct distribution in the rio Iguaçu and in the upper rio Uruguai (Ref. 87600). - 
Cichlidae Australoheros autochthon (Günther, 1862) Fr native     - 
Cichlidae Australoheros autrani Ottoni & Costa, 2008 Fr native   7.32 cm SL male/unsexed  Known from the Rio São João basin, Silva Jardim, Estado do Rio de Janeiro, southeastern Brazil (Ref. 79631). - 
Cichlidae Australoheros barbosae Ottoni & Costa, 2008 Fr native   9.62 cm SL male/unsexed  Known from the Rio Preto, rio Paraíba do Sul basin in Minas Gerais (Ref. 79631). - 
Cichlidae Australoheros capixaba Ottoni, 2010 Fr native    5.74 cm SL male/unsexed    - 
Cichlidae Australoheros charrua Říčan & Kullander, 2008 Fr native   7.79 cm SL male/unsexed  Type locality, Rio Uruguai drainage, road from Pirapo to São Nicolau, Arroyo Canoin, Rio Grande do Sul, MCP 13938 (holotype of Australoheros charrua, 7.79 cm SL) (Ref. 74689). - 
Cichlidae Australoheros facetus (Jenyns, 1842) Fr native  Cará (Portuguese), Acará (Portuguese), Acará camaleão (Portuguese), Acará cascudo (Portuguese), Chanchito (Portuguese), Papaterra (Portuguese)   19.30 cm SL male/unsexed  Found in coastal drainages of the Rio Grande do Sul State (Ref. 74689). Reported from the Uruguay River (Ref. 79585). + 
Cichlidae Australoheros forquilha Říčan & Kullander, 2008 Fr native   11.04 cm SL male/unsexed  Type locality, Rio Grande do Sul, Rio Forquilha, Rio Uruguai drainage, road from Maximiliano de Almeida to Machadinho, MCP 13936 (holotype of Australoheros forquilha, 11.04 cm SL, male) (Ref. 74689). - 
Cichlidae Australoheros ipatinguensis Ottoni & Costa, 2008 Fr endemic    5.35 cm SL male/unsexed  Known from the Rio Doce basin in Minas Gerais State (Ref. 79631). - 
Cichlidae Australoheros kaaygua Casciotta, Almirón & Gómez, 2006 Fr native   9.40 cm SL female  Known from a tributary of Río Paraná and tributaries of the Upper Rio Uruguay (Ref. 74689). - 
Cichlidae Australoheros macacuensis Ottoni & Costa, 2008 Fr native   8.32 cm SL male/unsexed  Known from the Rio Macacu basin, Cachoeiras de Macacu and Guapimirim in Estado do Rio de Janeiro, southeastern Brazil (Ref. 79631). - 
Cichlidae Australoheros macaensis Ottoni & Costa, 2008 Fr native   7.37 cm SL male/unsexed  Known from the Rio Macaé basin in southeastern Brazil (Ref. 79631). - 
Cichlidae Australoheros mattosi Ottoni, 2012 Fr native   8.04 cm SL male/unsexed  Known from the Rio Paraopeba and rio das Velhas drainages, rio São Francisco basin in Minas Gerais state, southeastern Brazil (Ref. 89866). - 
Cichlidae Australoheros minuano Říčan & Kullander, 2008 Fr native   8.39 cm SL male/unsexed  Type locality, Rio Grande do Sul, Arroyo Canoin, Rio Uruguai drainage, road from Pirapo to São Nicolau, MCP 12710 (holotype of Australoheros minuano, 7.08 cm SL). Known from the Middle and Lower Rio Uruguay (Ref. 74689). - 
Cichlidae Australoheros montanus Ottoni, 2012 Fr native   10.25 cm SL male/unsexed  Known from the Rio Paquequer drainage, rio Paraíba do Sul basin in Rio de Janeiro state, southeastern Brazil (Ref. 89866). - 
Cichlidae Australoheros muriae Ottoni & Costa, 2008 Fr native    12.13 cm SL male/unsexed  Known from the Rio Muriaé basin, rio Paraíba do Sul basin in southeastern Brazil (Ref. 79631). - 
Cichlidae Australoheros paraibae Ottoni & Costa, 2008 Fr native   6.11 cm SL male/unsexed  Known from the Rio do Peixe, rio Paraíba do Sul basin in Município de Juiz de Fora, Minas Gerais (Ref. 79631). - 
Cichlidae Australoheros perdi Ottoni, Lezama, Triques, Fragoso-Moura, Lucas & Barbosa, 2011 Fr native   16.70 cm TL male/unsexed 7.2 TL Found only in Parque Estadual do Rio Doce (PERD), lacustrine region of the middle Doce River basin, Doce River Valley in Marliéria municipality, Minas Gerais, southeastern Brazil (Ref. 87295). - 
Cichlidae Australoheros ribeirae Ottoni, Oyakawa & Costa, 2008 Fr endemic    7.55 cm SL male/unsexed  Known only from rio Ribeira do Iguape basin in southeastern Brazil (Ref. 75696). - 
Cichlidae Australoheros robustus Ottoni & Costa, 2008 Fr native   7.45 cm SL male/unsexed  Known from the Córrego da Areia, rio Paraíba do Sul basin in southeastern Brazil (Ref. 79631). - 
Cichlidae Australoheros sanguineus Ottoni, 2013 Fr native   10.53 cm SL male/unsexed  Known from the Rio Cubatão basin in Joinville municipality, Santa Catarina state, southern Brazil (Ref. 94124). - 
Cichlidae Australoheros saquarema Ottoni & Costa, 2008 Fr native   8.03 cm SL male/unsexed  Known from the Rio Mato Grosso basin, sistema lagoa de Saquarema in Estado do Rio de Janeiro, southeastern (Ref. 79631). - 
Cichlidae Australoheros scitulus (Říčan & Kullander, 2003) Fr native   11.00 cm SL male/unsexed  Known from the State of Rio Grande do Sul. + 
Cichlidae Australoheros taura Ottoni & Cheffe, 2009 Fr native   12.45 cm SL male/unsexed  Known from upper rio das Antas basin, rio Jacuí drainage, Laguna dos Patos system in Rio Grande do Sul (Ref. 81913). - 
Cichlidae Australoheros tavaresi Ottoni, 2012 Fr native   7.89 cm SL male/unsexed  Known from the upper rio Tietê drainage, upper rio Paraná basin in São Paulo state, southeastern Brazil (Ref. 89866). - 
Rivulidae Austrolebias adloffi (Ahl, 1922) Fr native  Peixe anual (Portuguese)   4.59 cm SL male/unsexed ;3.73 cm SL female  Known from lower rio Jacuí-Guaíba basin, including lower rio Gravataí, rio dos Sinos and rio Caí drainages, Rio Grande do Sul (Ref. 44045). Also Ref. 27139, 36579. + 
Rivulidae Austrolebias affinis (Amato, 1986) Fr questionable  Peixe anual (Portuguese)   5.00 cm TL male/unsexed  Outside distributional range, occurrence needs confirmation. + 
Rivulidae Austrolebias alexandri (Castello & López, 1974) Fr native  Peixe anual (Portuguese)   9.00 cm TL male/unsexed  Known from the Uruguay River basin (Ref. 36579). + 
Rivulidae Austrolebias araucarianus Costa, 2014 Fr native   3.52 cm SL male/unsexed ;3.09 cm SL female  Knonw from a single collection in a seasonal swamp close to the road BR-476, between the town São Mateus do sul and the village of Paulo Frontin, Paraná (Ref. 97355). - 
Rivulidae Austrolebias bagual Volcan, Lanés & Gonçalves, 2014 Fr endemic   3.93 cm SL male/unsexed  Currently known only for type locality, in the Encruzilhada do Sul municipality; from a small temporary pond, altitude of 46 m, associated with the floodplain of the Arroio Abranjo, in the middle course of the Rio Camaquã basin, Laguna dos Patos system, in flat areas surrounded by hills in geomorphological units of the Crystalline Shield of the Rio Grande do Sul State (Ref. 118216). - 
Rivulidae Austrolebias botocudo Lanés, Volcan & Maltchik, 2021 Fr native    Type locality of Austrolebias botocudo, drainages of upper rio Apuaê-Inhandava (upper rio Uruguay basin) (Ref. 123906). - 
Rivulidae Austrolebias camaquensis Volcan, Gonçalves & Lanés, 2017 Fr native    Type locality of Austrolebias camaquensis from a temporary pool in the floodplains of Arroio Santo Antônio (tributary of Rio Camaquã), close to BR-471 highway, Canguçu municipality, Rio Grande do Sul, Brazil, MCP 50817. - 
Rivulidae Austrolebias carvalhoi (Myers, 1947) Fr endemic  scarce (very unlikely) 3.73 cm SL male/unsexed ;3.81 cm SL female  Known from the Paraná River basin (Ref. 36579). Found in temporary pool at União da Vitoria, Estado do Paraná (Ref. 51692). - 
Rivulidae Austrolebias charrua Costa & Cheffe, 2001 Fr native    4.72 cm SL male/unsexed ;4.17 cm SL female  Known from Laguna dos Patos basin (Ref. 36579). Reccorded from coastal plains of southern Rio Grande do Sul adjacent to lagoa Mirim, between Curral Alto and Chuí (Ref. 44045). Museum: temporary pool close to arroio Chuí, road to Barra do Chuí, Rio Grande do Sul, MZUSP 60070 (holotype, male, 4.72 cm SL) (Ref. 44045). + 
Rivulidae Austrolebias cheffei Volcan, Barbosa, Robe & Lanés, 2021 Fr native    Type locality of Garcialebias cheffei in the western portion of the Laguna dos Patos system (Ref. 129237). - 
Rivulidae Austrolebias cyaneus (Amato, 1987) Fr native  Peixe anual (Portuguese)   5.00 cm TL male/unsexed  Known from Jacuí River basin (Ref. 36579). Type locality, floodplains of Arroio Dom Marcos, Municipio de Río Pardo, Río Grande do Sul (Ref. 36579). + 
Rivulidae Austrolebias ephemerus Volcan & Severo-Neto, 2019 Fr native   3.17 cm SL male/unsexed ;2.81 cm SL female  Type locality of Austrolebias ephemerus, temporary pool near 'do Bala' Road, Porto Murtinho, Mato Grosso do Sul State (Ref. 119764). - 
Rivulidae Austrolebias gymnoventris (Amato, 1986) Fr questionable   5.00 cm TL male/unsexed  Not in Ref. 36579; occurrence needs verification. + 
Rivulidae Austrolebias ibicuiensis (Costa, 1999) Fr native    5.00 cm TL male/unsexed  Known from the Uruguay River basin (Ref. 36579). Museum: rio Ibicuí-Mirim, rio Ibicuí drainage, rio Uruguai basin, road BR-287, between São Pedro do Sul and Santa Maria, Estado do Rio Grande do Sul, MCP 10201 (holotype) (Ref. 36604). - 
Rivulidae Austrolebias jaegari Costa & Cheffe, 2002 Fr native   3.04 cm SL male/unsexed  Known from Do Timba Swamp (banhado do Timba), Pelotas, Rio Grande do sul State (Ref. 36579). + 
Rivulidae Austrolebias juanlangi Costa, Cheffe, Salvia & Litz, 2006 Fr native   3.37 cm SL male/unsexed ;2.84 cm SL female  Known from the dos Patos lagoon system (Ref. 57613). + 
Rivulidae Austrolebias litzi Costa, 2006 Fr native    Known from the Dos Patos lagoon system and adjacent areas to the south (Ref. 57613). - 
Rivulidae Austrolebias lourenciano Volcan, Barbosa, Robe & Lanés, 2021 Fr native    Type locality of Austrolebias lourenciano from the western portion of the Laguna dos Patos system (Ref. 129237). - 
Rivulidae Austrolebias luteoflammulatus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete, 1965) Fr native    4.50 cm TL male/unsexed    + 
Rivulidae Austrolebias melanoorus (Amato, 1986) Fr questionable   6.00 cm TL male/unsexed  Rio Grande do Sul (Ref. 27139). Not in Ref. 36579, occurrence needs verification. + 
Rivulidae Austrolebias minuano Costa & Cheffe, 2001 Fr native    4.65 cm SL male/unsexed ;4.11 cm SL female  Recorded from coastal plains near the southernmost end of lagoa dos Patos, between Quinta and Rio Grande, southern Rio Grande do Sul (Ref. 44045). Museum: Temporary lagoon about 4.5 km N of Quinta, Rio Grande do Sul, MCP 28028 (holotype, male, 4.61 cm SL) (Ref. 44045). Also Ref. 36579. + 
Rivulidae Austrolebias nachtigalli Costa & Cheffe, 2006 Fr native   4.35 cm SL male/unsexed ;3.69 cm SL female  Known from the dos Patos lagoon system and adjacent areas to the south (Ref. 57613). + 
Rivulidae Austrolebias nigrofasciatus Costa & Cheffe, 2001 Fr native    5.80 cm TL male/unsexed  Recorded from localities along the inner coastal plains to lagoa Mirim, canal de São Gonçalo and tributaries, laguna dos Patos system, between Pelotas and Jaguarão, Rio Grande do Sul (Ref. 44045). Museum: Temporary pool in Pontal da Barra, praia, de Laranjal, Pelotas, Rio Grande do Sul, MCP 21172 (holotype, male, 4.27 cm SL) (Ref. 44045). Also Ref. 36579. + 
Rivulidae Austrolebias nubium Lanés, Volcan & Maltchik, 2021 Fr native    Type locality of Austrolebias nubium upper rio Taquari-Antas (upper rio Jacuí, Laguna dos Patos basin), in the Meridional Plateau (Ref. 123906). - 
Rivulidae Austrolebias patriciae (Huber, 1995) Fr questionable   4.00 cm TL male/unsexed  Not in Ref. 36579; occurrence needs verification. + 
Rivulidae Austrolebias paucisquama Ferrer dos Santos, Malabarba & Costa, 2008 Fr native   3.42 cm SL male/unsexed ;3.48 cm SL female  Known only from the type locality, a temporary pool in the rio Vacacaí drainage, rio Jacuí tributary, laguna dos Patos drainage (Ref. 76851). + 
Rivulidae Austrolebias pelotapes Costa & Cheffe, 2017 Fr native   3.14 cm SL male/unsexed ;2.94 cm SL female  Occurs in temporary pools and swamps associated to small streams tributaries to the northern margin of the Canal de São Gonçalo, Patos-Mirim lagoon system, Rio Grande do Sul (Ref. 118050). - 
Rivulidae Austrolebias periodicus (Costa, 1999) Fr native  Peixe anual (Portuguese)   5.00 cm TL male/unsexed  Known from the Uruguay River basin (Ref. 36579). Also Ref. 57613. + 
Rivulidae Austrolebias pongondo Costa & Cheffe, 2017 Fr native   4.09 cm SL male/unsexed ;3.71 cm SL female  Occurs only in temporary pools and swamps in the floodplains south of the São Gonçalo channel, Povo Novo, Rio Grande, Rio Grande do Sul state (Ref. 118117). - 
Rivulidae Austrolebias univentripinnis Costa & Cheffe, 2005 Fr native   3.56 cm SL male/unsexed ;3.22 cm SL female  Known from Jaguarão River floodplains, Mirim Lagoon basin in southern Brazil (Ref. 56780). + 
Rivulidae Austrolebias varzeae Costa, Reis & Behr, 2004 Fr native   3.37 cm SL male/unsexed  Known only from rio da Várzea floodplains, upper rio Uruguay basin in southern Brazil (Ref. 54764). - 
Rivulidae Austrolebias vazferreirai (Berkenkamp, Etzel, Reichert & Salvia, 1994) Fr questionable   10.00 cm TL male/unsexed  Rio Grande do Sul (Ref. 27139). Not in Ref. 36579; occurrence needs verification. + 
Rivulidae Austrolebias wolterstorffi (Ahl, 1924) Fr native    10.00 cm TL male/unsexed  Known from the Laguna dos Patos basin (Ref. 36579). Also Ref. 27139. + 
Gobiidae Awaous flavus (Valenciennes, 1837) Fr, Br native   8.20 cm SL male/unsexed ;7.62 cm SL female  Museum: Parà: freshwater stream in the vicinity of Belém, UMMZ 21377 (Ref. 26240). + 
Gobiidae Awaous tajasica (Lichtenstein, 1822) Fr native    16.30 cm SL male/unsexed  Known only from Piaui southward to Santa Catarina. + 
Characidae Axelrodia stigmatias (Fowler, 1913) Fr native    2.49 cm SL male/unsexed  Known from the upper Amazon River and middle Madeira River (Ref. 38376). + 
Ariidae Bagre marinus (Mitchill, 1815) Fr, Br, M native  Bagre-de-penacho (Portuguese), Bagre bandeirado (Portuguese), Bagre-amarelo (Portuguese), Bagre-bandeira (Portuguese), Bagre-branco (Portuguese), Bagre-de-fita (Portuguese), Bagre-fita (Portuguese), Bagre-mandim (Portuguese), Bagre-mandin (Portuguese), Bagre-sari (Portuguese), Bandeira (Portuguese), Bandeirado (Portuguese), Bandim (Portuguese), Peixe fita (Portuguese), Pira-bandeira (Portuguese), Pirá-bandeira (Portuguese), Sarassara (Portuguese), Sarassará (Portuguese), Sargento (Portuguese), Sarí (Portuguese)   69.00 cm TL male/unsexed 33 FL   + 
Pimelodidae Bagropsis reinhardti Lütken, 1874 Fr, Thr endemic  Mandi-bagre (Portuguese), Bagre (Portuguese), Mandi bagre (Portuguese)   22.70 cm SL male/unsexed  Known from Das Velhas River basin in São Francisco River drainage (Ref. 36506). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Type locality: Rio das Velhas, Minas Gerais, Brazil (Ref. 6868, 26282). - 
Characidae Bario steindachneri (Eigenmann, 1893) Fr native  Lambari (Portuguese)   9.00 cm SL male/unsexed  Found in the Amazon (Ref. 38376) and Machado River basin (Ref. 97589). - 
Loricariidae Baryancistrus chrysolomus Rapp Py-Daniel, Zuanon & Ribeiro de Oliveira, 2011 Fr native  Mango pleco (English), Aba laranja (Portuguese), Cascudo magnum (Portuguese)  29.60 cm TL male/unsexed  Found rio Xingu, in the area called Volta Grande do rio Xingu, immediately above Belo Monte falls and below Belo Monte village, and in rio Curuá, rio Iriri, the larger tributary of rio Xingu in Pará (Ref. 82796). + 
Loricariidae Baryancistrus longipinnis (Kindle, 1895) Fr endemic   20.00 cm TL male/unsexed  Known from the Tocantins River basin (Ref. 36713). - 
Loricariidae Baryancistrus niveatus (Castelnau, 1855) Fr endemic    34.00 cm TL male/unsexed  Known from Tocantins, Xingu, Tapajós and Trombetas River basins (Ref. 36713). Also Ref. 6868. + 
Loricariidae Baryancistrus xanthellus Rapp Py-Daniel, Zuanon & Ribeiro de Oliveira, 2011 Fr native  Golden nugget pleco (English), Amarelinho (Portuguese), Iriri golden nugget pleco (English), Cascudo pepita-de-ouro (Portuguese) common (usually seen) 29.70 cm TL male/unsexed  Known from Volta Grande do rio Xingu, an area immediately above Belo Monte falls, and from rio Iriri, the larger tributary of rio Xingu (Ref. 87296). + 
Pseudopimelodidae Batrochoglanis melanurus Shibatta & Pavanelli, 2005 Fr native   13.67 cm SL male/unsexed  Known only from the type locality, córrego Cancela, affluent of rio Cuiabá, rio Paraguai basin, State of Mato Grosso (Ref. 56694). - 
Pseudopimelodidae Batrochoglanis raninus (Valenciennes, 1840) Fr native  Pacamao (Portuguese), Peixe sapo (Portuguese)   20.00 cm SL male/unsexed  Also Ref. 2037. + 
Pseudopimelodidae Batrochoglanis villosus (Eigenmann, 1912) Fr native  Magabeira (Portuguese)   14.80 cm TL male/unsexed  Recorded from Machado (Ref. 97589), Purus and Acre River basins (Ref. 97592). + 
Belonidae Belonion apodion Collette, 1966 Fr native    5.00 cm SL male/unsexed    + 
Belonidae Belonion dibranchodon Collette, 1966 Fr native   4.80 cm SL male/unsexed  Known from the Negro River basin (Ref. 40653). + 
Pimelodidae Bergiaria westermanni (Lütken, 1874) Fr native  Bagre chancho (Portuguese), Mandi (Portuguese), Mandi bicudo (Portuguese), Mandi pirá (Portuguese), Papa isca açu (Portuguese), Trompudo (Portuguese)   19.70 cm SL male/unsexed  Known from Das Velhas River basin in São Francisco River drainage (Ref. 36506). Type locality: Rio das Velhas, Minas Gerais, Brazil (Ref. 26282, 6868). - 
Osphronemidae Betta splendens Regan, 1910 Fr introduced  Combatente (Portuguese), Peixe de briga (Portuguese)   6.50 cm TL male/unsexed    + 
Cichlidae Biotodoma cupido (Heckel, 1840) Fr native  Acará salema (Portuguese)   11.70 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36377). Also Ref. 4537. + 
Cichlidae Biotodoma wavrini (Gosse, 1963) Fr native   10.00 cm SL male/unsexed  Occurs in the Amazon River Basin (Ref. 36377). Also Ref. 4537. + 
Cichlidae Biotoecus opercularis (Steindachner, 1875) Fr endemic    10.00 cm TL male/unsexed  Known from the Amazon River basin, in the Branco River, the middle and lower Negro River, Urubu River, Lake Saracá, Parintins, Lake Carauaçu, lower Trombetas River (Ref. 36377). Type locality: Lago Saraca and Amazon at Villa Bella, Brazil (Ref. 12965). + 
Hemiodontidae Bivibranchia fowleri (Steindachner, 1908) Fr native    19.20 cm TL male/unsexed  Recorded from the Tocantins, Branco and Negro rivers (Ref. 598). Also found in Xingu, Tapajós and Madeira River basins (Ref. 38289). + 
Hemiodontidae Bivibranchia notata Vari & Goulding, 1985 Fr native   7.20 cm SL male/unsexed  Known from Tapajós and Tocantins River basins (Ref. 38289). Museum: beach at Alter do Chao, Rio Tapajós, Pará, MZUSP 28657 (holotype of B. notata, 6.83 cm SL) (Ref. 30185). - 
Hemiodontidae Bivibranchia simulata Géry, Planquette & Le Bail, 1991 Fr native   13.50 cm SL male/unsexed  Present in the Oyapock River which forms the border between Brazil and French Guiana (Ref. 12225). - 
Hemiodontidae Bivibranchia velox (Eigenmann & Myers, 1927) Fr native    16.30 cm TL male/unsexed  Known from Xingu and Tocantins River basins (Ref. 38289). Also Ref. 28819. - 
Characidae Boehlkea fredcochui Géry, 1966 Fr native   5.40 cm TL male/unsexed  Found in the Amazon River (Ref. 38376). + 
Characidae Boehlkea weitzmani Soares, Bertaco, Ito & Zuanon, 2017 Fr native   3.48 cm SL male/unsexed  Presently recorded only from streams of the rio Japurá basin, a left margin tributary of the rio Solimões basin in Amazonas State (Ref. 118101). - 
Ctenoluciidae Boulengerella cuvieri (Spix & Agassiz, 1829) Fr native  Bicuda (Portuguese), Pirapoucou (Portuguese), Bicudo (Portuguese), Dente de cão (Portuguese), Pirapoco (Portuguese), Pirapucu (Portuguese), Ueua (Portuguese)   88.00 cm FL male/unsexed  Known from Piauí (Rio Parnahyba), Amapá (Rio Araguari, Rio Cupixi), Pará (Rio Capim and tributary streams, Rio Tocantins, Rio Itacaiunas, Rio Trombetas, Igarapé Sororoca, Furo de Panaquera, Cametá, Rio Tapajós, Rio Jamanxim, Rio Xingu), Amazonas (Rio Urubu, Rio Amazonas, Paraná do Urucará, Lago Saracá, Lago Manacapuru, Rio Negro, Rio Jauaperi, Igarapé Baré, Lago Amana, Rio Tefé, Rio Javari), Mato Grosso (Rio Juruena, Rio Xingu), Goiás (Rio Araguaia, Rio Paraná), Roraima (Rio Negro, Rio Branco, and Igarapé Grande, tributary to Rio Uraricoera) and Rondonia (Rio Sao Domingo and Rio Machado, Lago do Paraiso). + 
Ctenoluciidae Boulengerella lateristriga (Boulenger, 1895) Fr native  Aicunga (Portuguese), Pirapocú (Portuguese)  25.80 cm SL male/unsexed  Found in Amazonas: Manaos, Igarapé Tarumazinho and tributaries, sandbank at Brazilian-Colombian border (west bank of Río Negro at Cucuhy), Rio Arirará, Ilha Cumuru and Ilha Tamaquaré (Rio Negro), Rio Urubaxi, Rio Negro, and Rio Marauiá. + 
Ctenoluciidae Boulengerella lucius (Cuvier, 1816) Fr native  Peixe agulha (Portuguese), Pirapoco (Portuguese), Pirapucu (Portuguese), Pirarucu (Portuguese)  43.00 cm SL male/unsexed  Known from Amazonas (Rio Urubu, Lago Saracá, Rio Negro, Lago Puraquequara, Rio Marauiá), Pará (Rio Trombetas, mouth of Rio Cuminá-Miri, Río Tapajós and Igarapé tributary to Rio Jamari). - 
Ctenoluciidae Boulengerella maculata (Valenciennes, 1850) Fr native  Ueua (Portuguese), Bicuda (Spanish), Uena (Spanish)   31.90 cm SL male/unsexed  Found in Pará (Rio Maicuru, Rio Trombetas, Rio Jamanxim, Rio Tocantins, Lagoas along margin of Rio Tocantins, Lagoa along margin of Igarapé Murú, Rio Tocantins above Tucuruí, and Rio Tapajós), Amazonas (Rio Urubu, Rio Amazonas, Rio Canuma, Igarapé do Rio Maués, Lago Januari, Manaus, Rio Preto da Eva, Region of Manaus, Manacapuru, Lago Saracá, Rio Purus, Rio Tefé, Rio Marauía, Lago Janauaca, Rio Negro, Rio Jauaperi, mouth of Rio Japurá, Rio Livramento, Rio Javari, and Lago do Rei), Roraima (Rio Branco), Rondonia (Rio Machado), and Mato Grosso (Upper Rio Juruena). + 
Ctenoluciidae Boulengerella xyrekes Vari, 1995 Fr native  Pirapoco (Portuguese)  38.20 cm SL male/unsexed  Found in Amazonas (Rio Negro basin, Rio Jauaperi, Rio Tefé and Rio Javari drainage) and Pará (Oriximiná) (Ref. 13118). Also Ref. 27925. - 
Characidae Brachychalcinus copei (Steindachner, 1882) Fr native  Machadinha (Portuguese)   9.00 cm TL male/unsexed  Found in the Machado (Ref. 97589) and Acre River basins (Ref. 97592). + 
Characidae Brachychalcinus parnaibae Reis, 1989 Fr native    7.20 cm SL male/unsexed  Known from Parnaiba River basin (Ref. 36891). Museum: Lagoas, Serra das Confusoes, Caracol, rio Panaiba system, Piaui, MZUSP 36594 (Ref. 27925). - 
Characidae Brachychalcinus reisi Garcia-Ayala, Ohara, Pastana & Benine, 2017 Fr native   6.13 cm SL male/unsexed  Found in the upper rio Curuá, a left side tributary of the rio Iriri, at the Serra do Cachimbo, rio Xingu basin, southern Pará State (Ref. 118114). - 
Characidae Brachychalcinus retrospina Boulenger, 1892 Fr native   6.90 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 36891). Type locality: Santa Cruz, Mato Grosso (Ref. 598). + 
Heptapteridae Brachyglanis frenatus Eigenmann, 1912 Fr native   9.90 cm SL male/unsexed   - 
Heptapteridae Brachyglanis microphthalmus Bizerril, 1991 Fr endemic   6.80 cm SL male/unsexed  Known from Trombetas River basin (Ref. 36914). Type locality: Igarapé Saracá of Lake Sapucuá, Rio Trombetas drainage, Pará, Brazil (Ref. 26282). - 
Heptapteridae Brachyglanis nocturnus Myers, 1928 Fr endemic  Jandiá (Portuguese)  8.10 cm SL male/unsexed  Found in Rio Negro (Ref. 36914). Also Ref. 6868. - 
Hypopomidae Brachyhypopomus alberti Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Sarapó (Portuguese)  11.10 cm TL male/unsexed ;10.00 cm TL female  Known from the upper rio Madeira (Amazonas drainage) and rio Guaporé (Ref. 116763). - 
Hypopomidae Brachyhypopomus arrayae Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Sarapó (Portuguese)  16.00 cm TL male/unsexed ;13.30 cm TL female  Known from the upper Madeira River basin (Ref. 116763). - 
Hypopomidae Brachyhypopomus batesi Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Sarapó (Portuguese)  12.00 cm TL male/unsexed ;12.10 cm TL female  Occurs in the central Amazon, near the main stem of the rio Solimões (Amazon), and in the upper rio Negro (Ref. 116763). - 
Hypopomidae Brachyhypopomus beebei (Schultz, 1944) Fr native  Itui (Portuguese), Tuvira (Portuguese)   32.00 cm SL male/unsexed  Captured in the Oyapock River which forms the border between Brazil and French Guiana (Ref. 12225). + 
Hypopomidae Brachyhypopomus belindae Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  scarce (very unlikely) 11.00 cm TL male/unsexed  Occurs only in the central Amazon River basin; from the type series near Tefé, Amazonas, and from a whitewater floodplain site near Manaus (Ref. 116763). - 
Hypopomidae Brachyhypopomus bennetti Sullivan, Zuanon & Cox Fernandes, 2013 Fr native   23.20 cm TL male/unsexed  Known from the Amazon basin (Ref. 94132). + 
Hypopomidae Brachyhypopomus brevirostris (Steindachner, 1868) Fr native  Tuvira (Portuguese), Itui (Portuguese)   34.70 cm TL male/unsexed  Captured in the Oyapock River which forms the border between French Guiana and Brazil (Ref. 12225). - 
Hypopomidae Brachyhypopomus bullocki Sullivan & Hopkins, 2009 Fr native    22.10 cm TL male/unsexed  Known from the rio Branco drainage (Ref. 81045). - 
Hypopomidae Brachyhypopomus cunia Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Sarapó (Portuguese)  17.60 cm TL male/unsexed ;14.10 cm TL female  Occurs only in rio Madeira; from its lower reaches below its major series of falls and rapids as far downstream as a site near the town of Calamã, Rondônia (near the mouth of the rio Machado), and from sites above the major series of falls, along most of the length of the rio Guaporé (Ref. 116763). - 
Hypopomidae Brachyhypopomus degy Dutra, Peixoto, Ochoa, Ohara, de Santana, Menezes & Datovo, 2021 Fr native   10.47 cm OT male/unsexed   - 
Hypopomidae Brachyhypopomus draco Giora, Malabarba & Crampton, 2008 Fr native    15.19 cm OT male/unsexed  Found in central, southern and coastal regions of Rio Grande do Sul (Ref. 76853). Known from Laguna dos Patos, Rio Tramandaí, and Rio Uruguay drainages (Ref. 76853). Collected 6 km east from the city of Mostardas in the Lagoa do Peixe National Park (Ref. 85215). + 
Hypopomidae Brachyhypopomus flavipomus Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Sarapó (Portuguese)  11.70 cm TL female  Known from the Amazon River basin (Ref. 116763). - 
Hypopomidae Brachyhypopomus gauderio Giora & Malabarba, 2009 Fr native    14.90 cm SL male/unsexed    + 
Hypopomidae Brachyhypopomus hamiltoni Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Sarapó (Portuguese)  12.50 cm TL male/unsexed ;9.70 cm TL female  Known from the Amazon River and Rio Negro (Ref. 116763). - 
Hypopomidae Brachyhypopomus hendersoni Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Sarapó (Portuguese)  19.50 cm TL male/unsexed ;20.30 cm TL female  Known from central Amazon from blackwater ria lakes near Tefé and the lower Negro (Ref. 116763) - 
Hypopomidae Brachyhypopomus janeiroensis (Costa & Campos-da-Paz, 1992) Fr native   18.60 cm TL male/unsexed   - 
Hypopomidae Brachyhypopomus jureiae Triques & Khamis, 2003 Fr native  Tuvira (Portuguese), Sarapó (Portuguese)   Known from a tributary of Rio Una do Prelado, which flows into the Atlantic Ocean, State of São Paulo in southeastern Brazil (Ref. 55506). - 
Hypopomidae Brachyhypopomus menezesi Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Tuvira (Portuguese)  11.90 cm TL male/unsexed ;11.20 cm TL female  Occurs in the middle and upper rio São Francisco drainage in Bahia and Minas Gerais (Ref. 116763). - 
Hypopomidae Brachyhypopomus pinnicaudatus (Hopkins, 1991) Fr, Fi native  Itui (Portuguese), Tuvira (Portuguese)   18.60 cm TL male/unsexed  Present in the Amazon basin (Ref. 12225). Found in Piracicaba river (Ref. 50076). + 
Hypopomidae Brachyhypopomus regani Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native  Sarapó (Portuguese)  15.60 cm TL male/unsexed ;14.10 cm TL female   - 
Hypopomidae Brachyhypopomus sullivani Crampton, de Santana, Waddell & Lovejoy, 2017 Fr native   15.20 cm TL male/unsexed ;12.70 cm TL female   - 
Hypopomidae Brachyhypopomus walteri Sullivan, Zuanon & Cox Fernandes, 2013 Fr native   17.50 cm TL male/unsexed  Known from the Amazon basin (Ref. 94132). + 
Pimelodidae Brachyplatystoma capapretum Lundberg & Akama, 2005 Fr native    58.10 cm SL male/unsexed    + 
Pimelodidae Brachyplatystoma filamentosum (Lichtenstein, 1819) Fr, Br, Fi native  Piriaba (Portuguese), Bagre amarelo (Portuguese), Bagre branco (Portuguese), Bandeirinha (Portuguese), Cadete (Portuguese), Chumbadinha (Portuguese), Dourada (Portuguese), Dourado (Portuguese), Filhote (Portuguese), Guirí (Portuguese), Jandiauva (Portuguese), Jandiáuva (Portuguese), Jundiáuva (Portuguese), Pirá-aíba (Portuguese), Pirahiba (Portuguese), Pirahiba pinimi (Portuguese), Piraiba (Portuguese), Piraíba (Portuguese), Piraíba aiua (Portuguese), Piraíba aiúa (Portuguese), Piraíba de pele (Portuguese), Piraíba grande (Portuguese), Piraíba ruim (Portuguese), Piramutaba (Portuguese), Piranambu (Portuguese), Piratinga (Portuguese), Urubarana (Portuguese)   360 cm TL male/unsexed    + 
Pimelodidae Brachyplatystoma juruense (Boulenger, 1898) Fr, Fi native  Dourada zebra (Portuguese), Jundiá (Portuguese), Sorubim (Portuguese), Sorubim flamengo (Portuguese)   60.00 cm TL male/unsexed    + 
Pimelodidae Brachyplatystoma platynema Boulenger, 1898 Fr, Fi native  Barbado (Portuguese), Babão (Portuguese), Bagre (Portuguese), Barba chata (Portuguese), Dourada-bandeira (Portuguese), Pintado (Portuguese), Surubim chicote (Portuguese)   100.00 cm SL male/unsexed    + 
Pimelodidae Brachyplatystoma rousseauxii (Castelnau, 1855) Fr native  Dourada (Portuguese)   192 cm TL male/unsexed    + 
Pimelodidae Brachyplatystoma tigrinum (Britski, 1981) Fr, Fi native  Sorubim (Portuguese), Zebra (Portuguese)   60.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36506). + 
Pimelodidae Brachyplatystoma vaillantii (Valenciennes, 1840) Fr, Br, Fi native  Piramutaba (Portuguese), Barba chata (Portuguese), Branquinho (Portuguese), Madi (Portuguese), Mota (Portuguese), Mulher ingrata (Portuguese), Normalista (Portuguese), Piramuta (Portuguese), Piramutá (Portuguese), Piramutana (Portuguese), Piramutata (Portuguese), Piramutatá (Portuguese), Piramutaua (Portuguese), Piramutáua (Portuguese), Piramutuba (Portuguese), Sorubim (Portuguese)   150 cm TL male/unsexed  An important commercial fish in the Rio Madeira (Ref. 6868). Also Ref. 5217. + 
Heptapteridae Brachyrhamdia heteropleura (Eigenmann, 1912) Fr native   4.30 cm SL male/unsexed  Occurs in the Negro River (Ref. 36914). + 
Heptapteridae Brachyrhamdia marthae Sands & Black, 1985 Fr native    7.60 cm SL male/unsexed    - 
Heptapteridae Brachyrhamdia meesi Sands & Black, 1985 Fr endemic   6.10 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36914). Type locality: near Belem, Brazil (Ref. 26282, 6868). + 
Heptapteridae Brachyrhamdia rambarrani (Axelrod & Burgess, 1987) Fr endemic   5.50 cm SL male/unsexed  Known from the Unini River basin in the upper Negro River drainage (Ref. 36914). Type locality: Rio Unini, trib. of Rio Negro, Amazonas, Brazil (Ref. 26282, 6868). + 
Heptapteridae Brachyrhamdia thayeria Slobodian & Bockmann, 2013 Fr native   5.42 cm SL male/unsexed  Type locality of the holotype of Brachyrhamdia thayeria: Rio Japura basin, Lago Amana, Maraa, Amazonas (Ref. 094149). - 
Characidae Brittanichthys axelrodi Géry, 1965 Fr native    2.81 cm SL male/unsexed  Type locality: Bulufu Beach on the Rio Itu, ca. 80 km upstream from the meeting with Rio Negro, Brazil, ca. 0°30'S, 63°30'W. + 
Characidae Brittanichthys myersi Géry, 1965 Fr native    3.17 cm SL male/unsexed  Type locality: Rio Negro, unnamed inlet on shore, ca. 13 km west of junction with Amazon, ca. 3°10'S, 59°55'W. - 
Loricariidae Brochiloricaria macrodon (Kner, 1853) Fr native  Cascudo espada (Portuguese), Cascudo viola (Portuguese)   26.80 cm SL male/unsexed  Found in the Paraguay River basin (Ref. 36389). Known from Rio Ciuabá (Ref. 6868). - 
Bryconidae Brycon amazonicus (Spix & Agassiz, 1829) Fr native  Jatuarana (Portuguese), Matrinchã (Portuguese), Piabanha (Portuguese), Pirabinha (Portuguese)   46.22 cm SL male/unsexed  Known from the Amazon River and its main tributaries (Ref. 38504). + 
Bryconidae Brycon cephalus (Günther, 1869) Fr, Fi misidentification  Sábalo (Portuguese), Jatuarana (Portuguese), Matrinxa (Portuguese), Matrinxã (Portuguese)   45.00 cm TL male/unsexed  Reported from Santarém. Also Ref. 9131. Probably a misidentification (occurrence in this country not confirmed by F.C.T. Lima). + 
Bryconidae Brycon devillei (Castelnau, 1855) Fr native  Piabanha (Portuguese) scarce (very unlikely) 14.30 cm SL male/unsexed  Regarded as threatened in the state of Minas Gerais (Ref. 26603). Type locality, Bahia (Ref. 30296). Also Ref. 38504. + 
Bryconidae Brycon falcatus Müller & Troschel, 1844 Fr native  Matrinchã (Portuguese), Jatuarana miri (Portuguese), Ladina (Portuguese), Mata gato (Portuguese), Matrichan (Portuguese), Matrinchão (Portuguese), Piabanha (Portuguese)   48.90 cm SL male/unsexed ;49.50 cm SL female    + 
Bryconidae Brycon ferox Steindachner, 1877 Fr endemic  Piabanha (Portuguese)   31.00 cm SL male/unsexed  Known from Mucuri River basin (Ref. 38504). - 
Bryconidae Brycon gouldingi Lima, 2004 Fr native  Matrinchã (Portuguese), Piabanha (Portuguese)   47.79 cm SL male/unsexed  Known only from the rio Tocantins basin, where it is widespread in the main river systems: the rio Tocantins itself, rio Araguaia, rio Parana and rio Itacaiunas (Ref. 55407). - 
Bryconidae Brycon hilarii (Valenciennes, 1850) Fr native  Piraputanga (Portuguese), Camapuã (Portuguese), Matrinchã (Portuguese), Matrinchão (Portuguese)   56.00 cm TL male/unsexed  Known from the Paraguay River basin (Ref. 38504). Reported to have a feeding association with the brown capuchin monkey Cebus apella in western Brazil. Monkeys during feeding on fruits from vegetation along river banks break and drop twigs, leaves, and fruits in the water below, thus, attracting the fish to feed on the fruits (Ref. 40097). + 
Bryconidae Brycon insignis Steindachner, 1877 Fr, Thr native  Piabanha (Portuguese)   36.90 cm SL male/unsexed  Known from Paraíba do Sul River basin (Ref. 38504). Recorded from the Tiete River, Sao Paulo. Regarded as threatened in the state of Minas Gerais (Ref. 26603). Endangered and possibly extinct (Ref. 3881). Also Ref. 30296. + 
Bryconidae Brycon melanopterus (Cope, 1872) Fr native  Jatuarana (Portuguese), Matrinchão (Portuguese)   38.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38504). + 
Bryconidae Brycon nattereri Günther, 1864 Fr native  Pirapitinga (Portuguese), Matrinchã (Portuguese), Peripetinga (Portuguese)   51.00 cm SL male/unsexed ;41.90 cm SL female  Found in the upper Paraná and São Francisco River basins (Ref. 38504). Regarded as threatened in the state of Minas Gerais (Ref. 26603). + 
Bryconidae Brycon opalinus (Cuvier, 1819) Fr native  Pirapitinga (Portuguese), Piabanha (Portuguese), Pirapetinga (Portuguese), Pirapitinga do sul (Portuguese)   26.30 cm SL male/unsexed  Known from Paraíba do Sul basin (Ref. 38504). Also Ref. 598. - 
Bryconidae Brycon orbignyanus (Valenciennes, 1850) Fr, Fi native  Bracanjuva (Portuguese), Matrinchã (Portuguese), Matrinchão (Portuguese), P'racanjuba (Portuguese), Piracanjuba (Portuguese), Piracanjuva (Portuguese), Pirapitonga (Portuguese), Piraputanga (Portuguese), Pracanjuva (Portuguese), Salmão-crioulo (Portuguese)   79.50 cm TL male/unsexed 24 TL Found in the Uruguay River (Ref. 79585). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 38504. + 
Bryconidae Brycon orthotaenia Günther, 1864 Fr, Fi native  Matrinchã (Portuguese), Matrinchão (Portuguese), Piracanjuba (Portuguese)   33.00 cm SL male/unsexed  Known from São Francisco River basin (Ref. 38504). Also Ref. 26333. + 
Bryconidae Brycon pesu Müller & Troschel, 1845 Fr native  Piabano (Portuguese), Arauiri (Portuguese), Pira miri (Portuguese)   18.90 cm SL male/unsexed  Also Ref. 12225. + 
Bryconidae Brycon vermelha Lima & Castro, 2000 Fr native  Vermelha (Portuguese)  39.50 cm SL male/unsexed  Known from the middle Rio Mucuri basin (Ref. 38873). - 
Characidae Bryconadenos tanaothoros Weitzman, Menezes, Evers & Burns, 2005 Fr native    Known from the tributaries of the upper rio Xingu and upper rio Tapajós basins in Mato Grosso (Ref. 56937). - 
Characidae Bryconadenos weitzmani Menezes, Netto-Ferreira & Ferreira, 2009 Fr native   4.13 cm SL male/unsexed  Found in the rio Curuá, a tributary of rio Iriri, rio Xingu basin in Altamira, Pará State (Ref. 81197). - 
Characidae Bryconamericus coeruleus Jerep & Shibatta, 2017 Fr native   6.54 cm SL male/unsexed   - 
Characidae Bryconamericus ecai da Silva, 2004 Fr native   7.51 cm SL male/unsexed  Known from a creek tributary of the lower portion of rio Taquari of laguna dos Patos drainage in Rio Grande do Sul (Ref. 54750). - 
Characidae Bryconamericus exodon Eigenmann, 1907 Fr native    5.70 cm SL male/unsexed  Recorded from Paraguay River (Ref. 38376). - 
Characidae Bryconamericus iheringii (Boulenger, 1887) Fr native  Lambari (Portuguese)   11.40 cm TL male/unsexed  Known from laguna dos Patos tributares, Rio Grande do Sul (Ref. 33287). Also found in the Uruguay River, southern Brazil (Ref. 79585). Also Ref. 598. + 
Characidae Bryconamericus ikaa Casciotta, Almirón & Azpelicueta, 2004 Fr native    6.80 cm SL male/unsexed    - 
Characidae Bryconamericus lambari Malabarba & Kindel, 1995 Fr native  Lambari (Portuguese)   5.60 cm SL male/unsexed  Found only in the type basin: the arroio Feitoria and tributaries, rio Cai drainage, laguna dos Patos drainage, Rio Grande do Sul. - 
Characidae Bryconamericus megalepis Fowler, 1941 Fr native  Matrinchã (Portuguese)  4.50 cm SL male/unsexed  Recorded from Ceara. - 
Characidae Bryconamericus microcephalus (Miranda Ribeiro, 1908) Fr native    7.70 cm SL male/unsexed  Found in the Ribeira de Iguape River basin (Ref. 38376). - 
Characidae Bryconamericus novae Eigenmann & Henn, 1914 Fr native   5.70 cm TL male/unsexed  Recorded from the Tocantins River basin (Ref. 38376). - 
Characidae Bryconamericus ornaticeps Bizerril & Perez-Neto, 1995 Fr native    6.50 cm SL male/unsexed  Found in the Macacu River basin in Rio de Janeiro (Ref. 38376 ). - 
Characidae Bryconamericus patriciae da Silva, 2004 Fr native   6.15 cm SL male/unsexed  Known from the headwaters of rio Pelotas in rio Uruguay drainage and rio das Antas in laguna dos Patos drainage (Ref. 54750). - 
Characidae Bryconamericus pinnavittatus Dagosta & Netto-Ferreira, 2015 Fr native   2.74 cm SL male/unsexed  Found only in the lower rio Teles Pires, rio Tapajós basin in Pará State (Ref. 99308). - 
Characidae Bryconamericus pyahu Azpelicueta, Casciotta & Almirón, 2003 Fr native       - 
Characidae Bryconamericus stramineus Eigenmann, 1908 Fr native  Lambari (Portuguese), Lambarizinho (Portuguese), Piaba (Portuguese), Piquira (Portuguese)   11.40 cm TL male/unsexed 3 TL Recorded from the Paraguay and Sao Francisco rivers (Ref. 598). Also found in the Uruguay River (Ref. 79585). Also Ref. 81048. + 
Characidae Bryconamericus tenuis Bizerril & Auraujo, 1992 Fr native    3.80 cm SL male/unsexed  Found in the São João River basin in Rio de Janeiro (Ref. 38376). - 
Characidae Bryconamericus ternetzi Myers, 1928 Fr native   5.90 cm TL male/unsexed  Reported from the upper Rio Negro. - 
Characidae Bryconamericus turiuba Langeani, Lucena, Pedrini & Tarelho-Pereira, 2005 Fr native   6.11 cm SL male/unsexed  Known from the upper Rio Parana system in Tiete, Parana, and Paranaiba rivers. - 
Characidae Bryconamericus uporas Casciotta, Azpelicueta & Almirón, 2002 Fr native   5.34 cm SL male/unsexed  Found in the Uruguay River basin (Ref. 38376). - 
Characidae Bryconella pallidifrons (Fowler, 1946) Fr native    2.32 cm SL male/unsexed  Found in the Amazon (Ref. 38376) and Machado River basin (Ref. 97589). + 
Characidae Bryconexodon juruenae Géry, 1980 Fr native   12.50 cm SL male/unsexed  Museum: Upper Rio Juruena, tributary of Rio Tapajoz, Mato Grosso, MZUSP 14638 (holotype of B. juruenae, 11.8 cm SL) (Ref. 27925). + 
Characidae Bryconexodon trombetasi Jégu, Santos & Ferreira, 1991 Fr native   11.70 cm SL male/unsexed  Museum: Rio Trombetas, Rio Cachorro, Parà, MZUSP 41301 (Ref. 27925). - 
Iguanodectidae Bryconops affinis (Günther, 1864) Fr native  Piaba (Portuguese)   12.00 cm TL male/unsexed    + 
Iguanodectidae Bryconops alburnoides Kner, 1858 Fr native    15.00 cm SL male/unsexed  Found in the Amazon River (Ref. 38376). + 
Iguanodectidae Bryconops caudomaculatus (Günther, 1864) Fr native  Pira miri (Portuguese)   12.40 cm TL male/unsexed  Present in the Amazon (Ref. 12225). Reported from Machado River basin (Ref. 97589). + 
Iguanodectidae Bryconops cyrtogaster (Norman, 1926) Fr native   12.00 cm TL male/unsexed  Endemic to the Oyapock River (Ref. 12225). + 
Iguanodectidae Bryconops disruptus Machado-Allison & Chernoff, 1997 Fr native   6.41 cm SL male/unsexed  Found in the Negro River (Ref. 38376). - 
Iguanodectidae Bryconops durbinae (Eigenmann, 1908) Fr native   3.06 cm SL male/unsexed  Known from Tapajós River basin (Ref. 38376). - 
Iguanodectidae Bryconops gracilis (Eigenmann, 1908) Fr endemic  scarce (very unlikely)  Type locality, Rio Tapajós (Ref. 598). - 
Iguanodectidae Bryconops inpai Knöppel, Junk & Géry, 1968 Fr native    10.00 cm TL male/unsexed  Found in the Negro River basin (Ref. 38376). - 
Iguanodectidae Bryconops melanurus (Bloch, 1794) Fr native    13.20 cm TL male/unsexed  Present in the Amazon basin (Ref. 12225). + 
Iguanodectidae Bryconops munduruku Silva-Oliveira, Canto & Ribeiro, 2015 Fr endemic    9.64 cm male/unsexed   - 
Iguanodectidae Bryconops piracolina Wingert & Malabarba, 2011 Fr native    7.13 cm SL male/unsexed  Reported from Machado river basin (Ref. 97589). - 
Iguanodectidae Bryconops tocantinensis Guedes, Oliveira & Lucinda, 2016 Fr native   6.50 cm SL male/unsexed  Known from rio Conceição, a tributary to the rio Palma, upper rio Tocantins drainage, Tocantins. Status of threat: could be classified as Least Concern (LC) based on IUCN categories and criteria since no relevant threats were detected within its distributional range (Ref. 109891). - 
Iguanodectidae Bryconops transitoria (Steindachner, 1915) Fr native   6.98 cm SL male/unsexed  Found in the Tapajós River basin (Ref. 38376). - 
Cichlidae Bujurquina cordemadi Kullander, 1986 Fr native    6.20 cm SL male/unsexed   - 
Cichlidae Bujurquina peregrinabunda Kullander, 1986 Fr native   10.70 cm SL male/unsexed  Found in Codajás (Ref. 36377). + 
Cichlidae Bujurquina vittata (Heckel, 1840) Fr native  Acará-pirambocaia (Portuguese), Acará (Portuguese), Cará (Portuguese)   9.00 cm SL male/unsexed  Known from the Paraná River basin (Ref. 36377). Type locality: Cuiabá, Mato Grosso, Brazil (Ref. 12965). Also Ref. 12251. + 
Aspredinidae Bunocephalus aleuropsis Cope, 1870 Fr native    9.10 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36695). - 
Aspredinidae Bunocephalus amaurus Eigenmann, 1912 Fr native   12.00 cm SL male/unsexed   - 
Aspredinidae Bunocephalus coracoideus (Cope, 1874) Fr native  Guitarrero (Portuguese), Guitarrinha (Portuguese), Rabeca (Portuguese)   11.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36695). + 
Aspredinidae Bunocephalus doriae Boulenger, 1902 Fr native    8.30 cm SL male/unsexed  Found in the Uruguay River (Ref. 79585). Also Ref. 6868. + 
Aspredinidae Bunocephalus erondinae Cardoso, 2010 Fr native   8.29 cm SL male/unsexed  Known from several tributaries to the laguna dos Patos system, Rio Grande do Sul (Ref. 85180). - 
Aspredinidae Bunocephalus hartti Carvalho, Cardoso, Friel & Reis, 2015 Fr native   5.77 cm SL male/unsexed  Found in several tributaries of the upper and middle rio São Francisco basins including the das Velhas, Paraopeba and Formoso rivers in Minas Gerais State (Ref. 104710). Status of threat: Least Concern (LC) as no specific threats to the species were detected (Ref. 104710). - 
Aspredinidae Bunocephalus knerii Steindachner, 1882 Fr native    13.00 cm SL male/unsexed    - 
Aspredinidae Bunocephalus larai Ihering, 1930 Fr native   5.56 cm SL male/unsexed  Known from the Paraná River basin (Ref. 36695). - 
Aspredinidae Bunocephalus minerim Carvalho, Cardoso, Friel & Reis, 2015 Fr native   4.88 cm SL male/unsexed  Found in several tributaries of the upper and middle rio São Francisco basins including the das Velhas, Formoso, Paraopeba and Paracatu rivers in Minas Gerais State (Ref. 104710). Status of threat: Least Concern (LC) as no threats to the species were detected (Ref. 104710). - 
Aspredinidae Bunocephalus verrucosus (Walbaum, 1792) Fr native    9.84 cm SL male/unsexed  Known from the Amazon (Ref. 36695) and Acre River basins (Ref. 97592). + 
Chilodontidae Caenotropus labyrinthicus (Kner, 1858) Fr, Fi native  Cabeça dura (Portuguese), Branquinha cascuda (Portuguese), Braquinha cascuda (Portuguese), Cabeça de fero (Portuguese), Cabeça de ferro (Portuguese), Casca grossa (Portuguese), Tariana (Portuguese), Tucano (Portuguese), Uchtuaué (Portuguese), Uhnéh (Portuguese)   14.80 cm SL male/unsexed ;25.30 cm SL female  Occurs in the Rio Paranaíba and the Amazonas basin (Ref. 27703). Also Ref. 598, 37477. + 
Chilodontidae Caenotropus mestomorgmatos Vari, Castro & Raredon, 1995 Fr native   19.20 cm TL male/unsexed  Occurs in the upper Rio Negro downstream to below the mouth of the Rio Daraá (Ref. 27703). Also Ref. 37477. - 
Chilodontidae Caenotropus schizodon Scharcansky & Lucena, 2007 Fr native   9.05 cm SL male/unsexed   + 
Characidae Caiapobrycon tucurui Malabarba & Vari, 2000 Fr native   4.53 cm SL male/unsexed  Found in the Tocantins River basin (Ref. 38376). - 
Callichthyidae Callichthys callichthys (Linnaeus, 1758) Fr native  Tamuatá (Portuguese), Caboje (Portuguese), Camboatá (Portuguese), Do mato (Portuguese), Soldado (Portuguese), Tamatá (Portuguese), Tamboatá (Portuguese), Tambuatá (Portuguese), Tamoatá (Portuguese), Tamuata (Portuguese)   21.00 cm TL male/unsexed  Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076) and Uruguay River (Ref. 79585). Found in Córrego Barreiro (Ref. 53011). + 
Pimelodidae Calophysus macropterus (Lichtenstein, 1819) Fr, Fi, Aq native  Piracatinga (Portuguese), Fidalgo (Portuguese), Piarcatinga (Portuguese), Pintadinha (Portuguese), Pintadinho (Portuguese), Piranambu (Portuguese), Piranambú (Portuguese), Piranambu amarelo (Portuguese), Piraquaruga (Portuguese), Urubu d'água (Portuguese)   40.00 cm TL male/unsexed    + 
Trichomycteridae Cambeva diffusa Costa, Feltrin & Katz, 2021 Fr native   1.12 cm SL male/unsexed  Type locality of Cambeva diffusa, Santa Catarina state: Urubici Muni.: Rio Urubici, Rio Canoas drainage, Rio Uruguai basin. Known from the western open plateau, in three localities in the upper Rio Canoas drainage, Rio Uruguai basin, in altitudes about 910-940 m asl (Ref. 129458). - 
Trichomycteridae Cambeva pascuali (Ochoa, Silva, Costa e Silva, Oliveira & Datovo, 2017) Fr native   4.94 cm SL male/unsexed  Type locality of Trichomycterus pascuali: Tamanduá R., Paranapanema Basin, São Paulo (Ref. 116172). - 
Rivulidae Campellolebias brucei Vaz-Ferreira & Sierra de Soriano, 1974 Fr, Fi, Or endemic  scarce (very unlikely) 4.50 cm TL male/unsexed  Known from ponds between Craciuma and Tubarao in Santa Catarina. Possibly extinct (Ref. 4537). Also Ref. 3881, 36579. + 
Rivulidae Campellolebias chrysolineatus Costa, Lacerda & Brasil, 1989 Fr endemic    5.00 cm TL male/unsexed  Also Ref. 27139. + 
Rivulidae Campellolebias dorsimaculatus Costa, Lacerda & Brasil, 1989 Fr endemic    4.00 cm TL male/unsexed  Known from the Ribeira de Iguape River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Campellolebias intermedius Costa & De Luca, 2006 Fr endemic    Known from the rio Ribeira de Iguape basin, São Paulo (Ref. 57633). + 
Cichlidae Caquetaia spectabilis (Steindachner, 1875) Fr, Fi native  Acará rosada (Portuguese), Acará rosado (Portuguese)   19.00 cm SL male/unsexed  Found in the Amazon River basin, from the Madeira and Uatumã River drainages to Gurupá and also in the Araguari River in Amapá; in the Branco River drainage (Ref. 36377). Also Ref. 12251. + 
Cyprinidae Carassius auratus (Linnaeus, 1758) Fr introduced  Dourado (Portuguese), Peixe dourado (Portuguese), Peixe japonês (Portuguese), Peixe vermelho (Portuguese)  48.00 cm TL male/unsexed   + 
Carcharhinidae Carcharhinus leucas (Valenciennes, 1839) Fr, Br native  Cabeça chata (Portuguese), Cação (Portuguese), Cação-fidalgo (Portuguese), Cação-flamengo (Portuguese), Sicuri-branco (Portuguese)  360 cm TL male/unsexed ;400 cm TL female  Known from the Amazon River (Ref. 79732). Although sometimes found in fish markets of Santarém, they are not utilized as food, but possibly kept there as tourist attractions (Ref. 12202). Also Ref. 103985. + 
Gasteropelecidae Carnegiella marthae Myers, 1927 Fr native  Borboleta de asas pretas (Portuguese)   2.81 cm SL male/unsexed  Recorded from the Rio Negro. + 
Gasteropelecidae Carnegiella myersi Fernández-Yépez, 1950 Fr native    2.15 cm SL male/unsexed  Found in the Acre River basin (Ref. 97592). + 
Gasteropelecidae Carnegiella schereri Fernández-Yépez, 1950 Fr native   2.60 cm SL male/unsexed  Known from the Amazon River (Ref. 39056). + 
Gasteropelecidae Carnegiella strigata (Günther, 1864) Fr native  Borboleta listrada (Portuguese), Borboleta pintada (Portuguese), Peixe borboleta (Portuguese), Peixe machado (Portuguese)   3.49 cm SL male/unsexed  Known from the Amazon (Ref. 39056), Machado (Ref. 97589) and Acre River basins (Ref. 97592). Also Ref. 12225. + 
Achiridae Catathyridium garmani (Jordan, 1889) Fr, Br, M native  Linguado (Portuguese), Linguado-lixa (Portuguese)   17.00 cm male/unsexed  Ranges from Rio de Janeiro southward (Ref. 36453). Occurs in the Lagoa dos Patos system, including freshwater portions (Ref. 36798). + 
Achiridae Catathyridium grandirivi (Chabanaud, 1928) Fr native   11.50 cm SL male/unsexed  Type locality: Rio Grande Do Sul (Ref. 46206). + 
Achiridae Catathyridium jenynsii (Günther, 1862) Fr native  Linguado (Portuguese), Arraia-sem-ferrão (Portuguese), Solha (Portuguese)   23.70 cm male/unsexed 10.8 TL   + 
Achiridae Catathyridium lorentzii (Weyenbergh, 1877) Fr native  Linguado (Portuguese)   5.40 cm male/unsexed    - 
Ariidae Cathorops agassizii (Eigenmann & Eigenmann, 1888) Fr native  Bagre gaivota (Portuguese)   22.50 cm TL male/unsexed  Known from Rio Grande do Sul. + 
Ariidae Cathorops arenatus (Valenciennes, 1840) Fr native   25.00 cm SL male/unsexed   + 
Serrasalmidae Catoprion mento (Cuvier, 1819) Fr, Fi native  Catirina (Portuguese), Mucura piranha (Portuguese), Pacu-piranha (Portuguese), Piranha (Portuguese), Piranha pacu (Portuguese)   15.00 cm SL male/unsexed  Recorded from Mato Grosso. Also Ref. 39031. + 
Doradidae Centrodoras brachiatus (Cope, 1872) Fr native    41.00 cm TL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Doradidae Centrodoras hasemani (Steindachner, 1915) Fr native   21.00 cm SL male/unsexed  Known from Negro River basin (Ref. 37054). + 
Auchenipteridae Centromochlus akwe Coelho, Chamon & Sarmento-Soares, 2021 Fr native   7.38 cm SL male/unsexed  Type locality of Centromochlus akwe, Tocantins, Pium, Pedral da Sambaíba, Ilha do Bananal, Javaés River. Known from Tocantins-Araguaia River basin and reported from the upper and middle stretches of the Tocantins River; and in median and lower portions of the Araguaia River basin, at Javaés River (Ilha do Bananal) and at Araguaia River near the confluence to the Tocantins River (Ref. 123897). - 
Auchenipteridae Centromochlus existimatus Mees, 1974 Fr native   9.02 cm SL male/unsexed  Found in the Amazon River (Ref. 37098). Known from the Amazonas: paraná of Marchantaria I.; Manaus harbor; Turuté and in Pará, Santarém (Ref. 39641). Also Ref. 37098. + 
Auchenipteridae Centromochlus heckelii (De Filippi, 1853) Fr native    13.90 cm SL male/unsexed    + 
Auchenipteridae Centromochlus macracanthus Soares-Porto, 2000 Fr native   12.97 cm SL male/unsexed  Known only from the rio Negro drainage, in the Amazon (Ref. 39641). - 
Auchenipteridae Centromochlus melanoleucus (Vari & Calegari, 2014) Fr native   3.24 cm SL male/unsexed  Known from the rio Teles Pires in the rio Tapajós catchment in the southern portion of the Amazon basin (Ref. 97857). + 
Auchenipteridae Centromochlus orca Sarmento-Soares, Lazzarotto, Rapp Py-Daniel & Leitão, 2017 Fr native   5.68 cm SL male/unsexed  Type locality of Centromochlus orca, Pará, Terra Santa, mouth of Igarapé Jamari with lago de Terra Santa, rio Nhamundá basin. Reported from the mouth of igarapé Jamari, a tributary of the lower rio Nhamundá (western Pará), and from two close localities in lagoa Sete Ilhas upstream from Nhamundá, on boundary between Amazonas and Pará, in a region along the transition between the Amazonas floodplain and the Guiana Shield (Ref. 118068). + 
Auchenipteridae Centromochlus schultzi Rössel, 1962 Fr native   10.89 cm SL male/unsexed  Known from the upper Xingu and Tocantins River basins (Ref. 37098). Also Ref. 6868. + 
Centropomidae Centropomus ensiferus Poey, 1860 Fr, Br, M native  Robalo-galhudo (Portuguese), Camorim-cabo-de-machado (Portuguese), Camorim-peba (Portuguese), Camorim-sovela (Portuguese), Camuri (Portuguese), Camurim (Portuguese), Camurim-branco (Portuguese), Camurim-sovela (Portuguese), Camuripeba (Portuguese), Robalete (Portuguese), Robalo (Portuguese), Robalo-corcunda (Portuguese)  36.20 cm TL male/unsexed  Also Ref. 26340. + 
Centropomidae Centropomus irae Carvalho-Filho, Oliveira, Soares & Araripe, 2019 Fr, Br, M native  Ira’s snook (English), Camorim Irá (Portuguese)  53.55 cm SL male/unsexed  Type locality of <><>, Amapá, Oiapoque, Baía do Oiapoque. Known from Oiapoque Bay, between Brazil and French Guyana, and the Lago Piratuba Biological Reserve, both of which are in Amapá state (Ref. 121036). + 
Centropomidae Centropomus parallelus Poey, 1860 Fr, Br, M native  Robalo peba (Portuguese), Cambriaçu (Portuguese), Camburiapeva (Portuguese), Camorim-corcunda (Portuguese), Camorim-peba (Portuguese), Camorim-pena (Portuguese), Camorim-tapa (Portuguese), Camuri (Portuguese), Camurim (Portuguese), Camurim branco (Portuguese), Camurim peva (Portuguese), Camurim-amarelo (Portuguese), Camurim-apuá (Portuguese), Camurim-corcunda (Portuguese), Camuripeba (Portuguese), Camurupeba (Portuguese), Cangoropeba (Portuguese), Cangurupeba (Portuguese), Robalo (Portuguese), Robalo peva (Portuguese), Robalo-peba (Portuguese)   72.00 cm TL male/unsexed  Ranges south to Florianopolis (Ref. 36507). Also Ref. 7251, 26340. + 
Centropomidae Centropomus pectinatus Poey, 1860 Fr, Br, M native  Robalo-constantino (Portuguese), Camorim-corcunda (Portuguese), Camorim-sovela (Portuguese), Camorim-sovela (Portuguese), Camorim-ticopá (Portuguese), Camorim-ticopá (Portuguese), Camuri (Portuguese), Camurim (Portuguese), Robalo (Portuguese), Robalo-constantino (Portuguese)   56.00 cm TL male/unsexed  Also Ref. 26340 and 36880. + 
Centropomidae Centropomus undecimalis (Bloch, 1792) Fr, Br, M native  Robalo-de-galha (Portuguese), Bicudo (Portuguese), Cambriaçu (Portuguese), Camburiaçu (Portuguese), Camorim (Portuguese), Camorim-açu (Portuguese), Camuri (Portuguese), Camurim (Portuguese), Camurim branco (Portuguese), Camurim-açu (Portuguese), Camurim-cabo-de-machado (Portuguese), Camurim-preto (Portuguese), Camurimpema (Portuguese), Camuripeba (Portuguese), Camuripema (Portuguese), Cangoropeba (Portuguese), Canjurupeba (Portuguese), Escalho (Portuguese), Robalão (Portuguese), Robalo (Portuguese), Robalo-bicudo (Portuguese), Robalo-branco (Portuguese), Robalo-camurim (Portuguese), Robalo-estoque (Portuguese), Robalo-flecha (Portuguese), Robalo-flexa (Portuguese), Rolão (Portuguese)   140 cm TL male/unsexed  Also Ref. 26340. + 
Pseudopimelodidae Cephalosilurus fowleri Haseman, 1911 Fr endemic  Peixe-sapo (Portuguese), Pacamon (Portuguese)  40.50 cm TL male/unsexed  Known from São Francisco River basin (Ref. 39418). Also Ref. 6868. + 
Cetopsidae Cetopsidium ferreirai Vari, Ferraris & de Pinna, 2005 Fr native   3.70 cm SL male/unsexed  Known only from rio Trombetas, a left bank tributary of the lower rio Amazonas (Ref. 56045). - 
Cetopsidae Cetopsidium minutum (Eigenmann, 1912) Fr native   4.90 cm SL male/unsexed   + 
Cetopsidae Cetopsidium orientale (Vari, Ferraris & Keith, 2003) Fr native    5.80 cm SL male/unsexed    - 
Cetopsidae Cetopsidium pemon Vari, Ferraris & de Pinna, 2005 Fr native   4.26 cm SL male/unsexed  Known from the upper portions of the rio Branco in northern Brazil (Ref. 56045). + 
Cetopsidae Cetopsis arcana Vari, Ferraris & de Pinna, 2005 Fr native   9.00 cm SL male/unsexed  Known from Rio Tocantins basins (Ref. 56045). - 
Cetopsidae Cetopsis caiapo Vari, Ferraris & de Pinna, 2005 Fr native   6.90 cm SL male/unsexed  Known from Rio Tocantins basin (Ref. 56045). - 
Cetopsidae Cetopsis candiru Spix & Agassiz, 1829 Fr native  Candiru (Portuguese), Candiru açu (Portuguese), Candiru caçu (Portuguese), Candiru piranga (Portuguese), Candiru vermelho (Portuguese)   26.30 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36486). Type locality, equatorial rivers (Ref. 26282). + 
Cetopsidae Cetopsis coecutiens (Lichtenstein, 1819) Fr native  Candiru (Creole, Portuguese), Candiru-açú (Creole, Portuguese), Piracatinga (Creole, Portuguese), Canderú (Portuguese)   27.30 cm TL male/unsexed  Known from Amazon and Tocantins River basins (Ref. 36486). Type locality: Rivers of equatorial Brazil (Ref. 26282). + 
Cetopsidae Cetopsis gobioides Kner, 1858 Fr native  Candiru-açú (Creole, Portuguese), Candiru (Portuguese)   10.90 cm SL male/unsexed  Type locality, Irisanga (Ref. 26282, 6868). Also Ref. 36486. + 
Cetopsidae Cetopsis oliveirai (Lundberg & Rapp Py-Daniel, 1994) Fr native    3.60 cm SL male/unsexed  Known from Solimoes and Amazon rivers (Ref. 33290). Also Ref. 36486. + 
Cetopsidae Cetopsis parma Oliveira, Vari & Ferraris, 2001 Fr native    17.00 cm SL male/unsexed   + 
Cetopsidae Cetopsis plumbea Steindachner, 1882 Fr native    11.80 cm SL male/unsexed    + 
Cetopsidae Cetopsis sandrae Vari, Ferraris & de Pinna, 2005 Fr native   7.50 cm SL male/unsexed  Known from Rio Tapajos system, Amazon basin (Ref. 56045). - 
Cetopsidae Cetopsis sarcodes Vari, Ferraris & de Pinna, 2005 Fr native   6.90 cm SL male/unsexed  Known from Rio Tocantins (Ref. 56045). - 
Heptapteridae Cetopsorhamdia iheringi Schubart & Gomes, 1959 Fr endemic  Bagrinho (Portuguese), Lobó (Portuguese), Mandi (Portuguese)   11.10 cm SL male/unsexed  Occurs in the upper Paraná and upper São Francisco River basins (Ref. 36914) and Mogi Guaçu River, São Paulo (Ref. 127242), + 
Heptapteridae Cetopsorhamdia insidiosa (Steindachner, 1915) Fr endemic   7.70 cm SL male/unsexed  Known from the Rio Branco and Rio Surumu (Ref. 6868). Also Ref. 36914. + 
Heptapteridae Cetopsorhamdia molinae Miles, 1943 Fr native   3.60 cm SL male/unsexed  Occurs in the Tocantins River basin (Ref. 36914). - 
Cichlidae Chaetobranchopsis australis Eigenmann & Ward, 1907 Fr native  Acara prata (Portuguese), Cará (Portuguese)   12.00 cm SL male/unsexed  Known from the Paraná River basin in the Paraguay River (Ref. 36377). + 
Cichlidae Chaetobranchopsis orbicularis (Steindachner, 1875) Fr, Fi native  Acará cascudo (Portuguese), Acará tucuma (Portuguese), Acará tucumã (Portuguese) common (usually seen) 12.00 cm SL male/unsexed  Known from the Amazon River basin, along the Amazon River from the mouth or the Negro River to Marajó Island, and in Amapá (Ref. 36377). Type locality: Amazon R. at Para, Santarim, Gurupa, Rio Xingu at Porto do Noz; Rio Negro, and Rio Hyuvari. Also Ref. 12251. + 
Cichlidae Chaetobranchus flavescens Heckel, 1840 Fr, Fi native  Acará prata (Portuguese), Cará oião (Portuguese), Cará preto (Portuguese)   21.00 cm SL male/unsexed ;26.00 cm TL female 22 TL Known from the Amazon River basin and rivers in Amapá (Ref. 36377). Type locality: Rio Guaporé, trib. of Rio Negro, Mato Grosso. Found in fish markets in Santarém (Ref. 12202). Also Ref. 12251. + 
Cichlidae Chaetobranchus semifasciatus Steindachner, 1875 Fr endemic   23.00 cm SL male/unsexed  Known from Amazon River basin, along the Amazon-Solimões River from Tabatinga to Óbidos (Ref. 36377). Type locality: Amazon R. at Obidos, Codajas, Teffe, Rio Ica, Lake Hyanuary, Saraca at Silva, Brazil (Ref. 12965). + 
Loricariidae Chaetostoma jegui Rapp Py-Daniel, 1991 Fr endemic   16.80 cm SL male/unsexed  Known from the Uraricoera and Tacutu River basins in the Branco River drainage (Ref. 36713). Type locality: Rio Uraricoera, Federal Territory of Roraima (Ref. 26719). - 
Chalceidae Chalceus epakros Zanata & Toledo-Piza, 2004 Fr native    17.40 cm TL male/unsexed    + 
Chalceidae Chalceus erythrurus (Cope, 1870) Fr native   24.50 cm SL male/unsexed  Found in the Amazon River (Ref. 38376). + 
Chalceidae Chalceus guaporensis Zanata & Toledo-Piza, 2004 Fr native    17.40 cm SL male/unsexed  Known from the upper Rio Madeira (Ref. 55827). + 
Chalceidae Chalceus latus Jardine, 1841 Fr native     - 
Chalceidae Chalceus macrolepidotus Cuvier, 1818 Fr native  Arari-pirá (Portuguese), Arari (Portuguese), Araripira (Portuguese), Araripirá (Portuguese), São Pedro (Portuguese), Saragui (Portuguese)   25.00 cm SL male/unsexed    + 
Chalceidae Chalceus spilogyros Zanata & Toledo-Piza, 2004 Fr native    Known from the lower Rio Tapajós and rio Trombetas (Ref. 55827). - 
Crenuchidae Characidium alipioi Travassos, 1955 Fr native    6.35 cm SL male/unsexed  Occurs in Paraíba do Sul River basin (Ref. 37059). Type locality, Ilha dos Pombos, Rio Paraiba, Estado do Rio (Ref. 26282). - 
Crenuchidae Characidium bahiense Almeida, 1971 Fr native    2.60 cm SL male/unsexed  Museum: Arembepe, Bahia, MZUSP 8940 (holotype of C. bahiensis, 1.6 cm SL, female) (Ref. 27925). Also Ref. 37059. - 
Crenuchidae Characidium bimaculatum Fowler, 1941 Fr native    6.70 cm SL male/unsexed  Found in coastal streams of northeastern Brazil (Ref. 37059). Type locality, Fortaleza, Ceará (Ref. 26282). + 
Crenuchidae Characidium boavistae Steindachner, 1915 Fr native   5.27 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37059). Type locality: Río Branco, n. Brazil (Ref. 26282). + 
Crenuchidae Characidium brevirostre Pellegrin, 1909 Fr native   3.27 cm SL male/unsexed  Found in coastal streams in Amapá (Ref. 37059). Type locality: Carsevenne R., n. Brazil. + 
Crenuchidae Characidium crandellii Steindachner, 1915 Fr native   6.44 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37059). Type locality: Rio Miang, trib. Cotingo, Tacutu; Boa Vista, Rio Branco, Brazi (Ref. 26282). - 
Crenuchidae Characidium declivirostre Steindachner, 1915 Fr native  Caruru piramiri (Portuguese)  7.97 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37059). - 
Crenuchidae Characidium deludens Zanata & Camelier, 2015 Fr native   4.83 cm SL male/unsexed  Occurs in rio Cochó and rio Santo Antônio, tributaries of upper rio Paraguaçu basin, Bahia State (Ref. 116766). - 
Crenuchidae Characidium etheostoma Cope, 1872 Fr native   4.15 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37059). - 
Crenuchidae Characidium fasciatum Reinhardt, 1867 Fr, Thr native  Canivete (Portuguese), Lambari (Portuguese)   6.74 cm SL male/unsexed  Known from Das Velhas River in São Francisco River drainage and Paranaíba, Grande and Tietê rivers in the upper Paraná River drainage (Ref. 37059). Type locality, near Near Lagoa Santa (Ref. 30296). Regarded as threatened in the state of Minas Gerais (Ref. 26603). + 
Crenuchidae Characidium gomesi Travassos, 1956 Fr native  Canivete (Portuguese)   6.49 cm SL male/unsexed  Occurs in Grande, Tietê and Paranapanema rivers of the upper Paraná River drainage (Ref. 37059). Type locality: Córrego da Lazica, Ouro Fino, Minas Gerais, Bacia de Mogi-Guaçu, Pirassununga, Brazil (Ref. 26282). + 
Crenuchidae Characidium grajahuense Travassos, 1944 Fr native  Canivetinho (Portuguese), Mocinha (Portuguese)   8.81 cm male/unsexed  Occurs in coastal streams between Guanabara Bay and Mangaratiba, Rio de Janeiro (Ref. 37059). Type locality, Grajaú, Rio de Janeiro (Ref. 30296). - 
Crenuchidae Characidium hasemani Steindachner, 1915 Fr native   6.76 cm SL male/unsexed  Known from northern tributaries of the Amazon River basin (Ref. 37059). Type locality: Rio Surumi at Serra do Melho and Rio Rupununi, Brazil (Ref. 26282). - 
Crenuchidae Characidium heirmostigmata da Graça & Pavanelli, 2008 Fr native  Canivete (Spanish), Mocinha (Spanish)  5.40 cm SL male/unsexed  Found only in rio Abelha, rio Barra Grande and rio Nestor, tributaries to rio Ivaí, upper rio Paraná basin in Paraná State (Ref. 74998). - 
Crenuchidae Characidium helmeri Zanata, Sarmento-Soares & Martins-Pinheiro, 2015 Fr native   4.04 cm SL male/unsexed  Found in various small coastal rivers in Southern Bahia, in the vicinity of Canavieiras, Porto Seguro, and Prado (Ref. 104900). - 
Crenuchidae Characidium interruptum Pellegrin, 1909 Fr native   5.28 cm SL male/unsexed  Occurs in coastal lowland streams of southeastern Brazil (Ref. 37059). Type locality: Serra d'Estrello(Ref. 26282). + 
Crenuchidae Characidium japuhybense Travassos, 1949 Fr native    5.54 cm SL male/unsexed  Occurs in coastal streams of southeastern Brazil from Ilha Grande Bay to Ribeira de Iguape River basin (Ref. 37059). Type locality: Japuhyba [Japuíba], Angra dos Reis, Estado do Rio de Janeiro, Brazil (Ref. 26282). - 
Crenuchidae Characidium kalunga Melo, Bouquerel, Masumoto, França & Netto-Ferreira, 2021 Fr native   4.87 cm SL male/unsexed  Type locality of Characidium kalunga, Alto Paraíso de Goiás (Ref. 124633). - 
Crenuchidae Characidium kamakan Zanata & Camelier, 2015 Fr native   5.53 cm SL male/unsexed  Known from rio Água Preta and rio Panelão, tributaries of the lower portion of rio Pardo basin, Bahia State. In the absence of imminent threats, this species could be placed under Least Concern (LC) category based on the IUCN classification (Ref. 116766). - 
Crenuchidae Characidium lagosantense Travassos, 1947 Fr, Thr native  Canivete (Portuguese)   4.13 cm SL male/unsexed  Known from Das Velhas River basin in São Francisco River drainage (Ref. 37059). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Museum: Lagoa Santa, Minas Gerais, MNRJ 4582 (Holotype) (Ref. 26282). Also Ref. 30296. + 
Crenuchidae Characidium lanei Travassos, 1967 Fr native    6.52 cm SL male/unsexed  Found in coastal basins of southeastern Brazil in Paraná State and Ribeira de Iguape River basin. (Ref. 37059). Type locality: Fazenda Poço Grande, Juquiá, Sao Paulo, Brazil (Ref. 26282). + 
Crenuchidae Characidium laterale (Boulenger, 1895) Fr native    3.50 cm SL male/unsexed  Found in Pantanal (Ref. 81048). + 
Crenuchidae Characidium lauroi Travassos, 1949 Fr native    7.12 cm SL male/unsexed  Occurs in the middle and upper Paraíba do Sul River basin (Ref. 37059). Type locality: Rio das Pedras, Fazenda Pendo, Agulhas Negras, Estado do Rio de Janeiro, Brazil (Ref. 26282). - 
Crenuchidae Characidium litorale Leitão & Buckup, 2014 Fr native   4.52 cm SL male/unsexed  Known from the Rio São João, Rio Macaé, and Rio Imbé drainages in located in the extreme northeastern slopes of Serra do Mar, northeast of Rio de Janeiro state (Ref. 96085). - 
Crenuchidae Characidium macrolepidotum (Peters, 1868) Fr native  occasional (usually not seen) 6.10 cm SL male/unsexed   - 
Crenuchidae Characidium mirim Netto-Ferraira, Birindelli & Buckup, 2013 Fr native   2.34 cm SL male/unsexed   - 
Crenuchidae Characidium nana Mendonça & Netto-Ferreira, 2015 Fr native   2.53 cm SL male/unsexed  Known from the Rio 13 de Maio, in the Rio Curuá, at Serra do Cachimbo, and the Rio Parazinho, both in the Rio Xingu drainage, and from Igarapé Negro, in the Rio Tapajós drainage in Pará (Ref. 104905) - 
Crenuchidae Characidium nupelia da Graça, Pavanelli & Buckup, 2008 Fr native  Mocinha (Spanish)  3.19 cm SL male/unsexed  Known from the tributary streams of Rio Cuiabá located in the highlands upstream from the Pantanal Matogrossense, upper Rio Paraguay basin in the State of Mato Grosso (Ref. 75787). - 
Crenuchidae Characidium occidentale Buckup & Reis, 1997 Fr native   4.83 cm SL male/unsexed  Known from the left bank tributaries of the middle Rio Uruguay drainage in the state of Rio Grande do Sul, Brazil (Ref. 27672). Also Ref. 37059. - 
Crenuchidae Characidium oiticicai Travassos, 1967 Fr native   6.75 cm SL male/unsexed  Known from the upper Tietê and Ribeira de Iguape River basins (Ref. 37059). Type locality: Paranapiacaba, Sao Paulo, Brazil (Ref. 26282). + 
Crenuchidae Characidium onca Melo, Brito Ribeiro & Lima, 2021 Fr native   4.41 cm SL male/unsexed  Type locality of Characidium onca, córrego Taquara at Reserva Ecológica do IBGE, Brasilia, Distrito Federal (Ref. 123789). - 
Crenuchidae Characidium orientale Buckup & Reis, 1997 Fr native   5.70 cm SL male/unsexed  Known from western tributaries of the laguna dos Patos drainage, in Rio Grande do Sul state, Brazil (Ref. 27672). Also Ref. 37059. - 
Crenuchidae Characidium papachibe Peixoto & Wosiacki, 2013 Fr native   2.66 cm SL male/unsexed  Occurs in an unnamed stream, left tributary to Rio Aruã, and from the Lago São Francisco do Alto Aruã, at the Rio Aruã, left tributary to Rio Arapiuns, left tributary to Rio Tapajós, tributary to the Rio Amazonas, Município de Juruti in Pará (Ref. 93226). - 
Crenuchidae Characidium pterostictum Gomes, 1947 Fr native    8.70 cm SL male/unsexed 57 TL Known from the Uruguay River basin (Ref. 37059). + 
Crenuchidae Characidium rachovii Regan, 1913 Fr native  Canivete (Portuguese)  4.50 cm SL male/unsexed   + 
Crenuchidae Characidium roesseli Géry, 1965 Fr native   3.06 cm SL male/unsexed  Occurs in the upper Amazon River basin (Ref. 37059). Type locality: Igarapé Préto, along Upper Amazon, near Belem, about 60 km below Leticia, Brazil (Ref. 26282). - 
Crenuchidae Characidium samurai Zanata & Camelier, 2014 Fr native   4.66 cm SL male/unsexed  Found in the rio das Almas and rio Vermelho basins in Bahia State, eastern Brazil (Ref. 96872). - 
Crenuchidae Characidium satoi Melo & Oyakawa, 2015 Fr native   4.43 cm SL male/unsexed  Known only from a single locality, the Córrego Curral das Éguas, a small tributary of the right margin of Rio Abaeté, in the Rio São Francisco basin (Ref. 104008). - 
Crenuchidae Characidium schubarti Travassos, 1955 Fr native    51.30 cm SL male/unsexed  Found in Paranapanema basin in upper Paraná River drainage and Ribeira de Iguape River basin (Ref. 37059). Type locality: Córrego entre Murtinhos e Jaguariaíva, Paraná, Brazil (Ref. 26282). - 
Crenuchidae Characidium serrano Buckup & Reis, 1997 Fr native  Piquira (Portuguese)  5.40 cm SL male/unsexed  Known from the upper reaches of the Rio Uruguay drainage (Ref. 27672). Also Ref. 37059, 79585. - 
Crenuchidae Characidium steindachneri Cope, 1878 Fr native   4.12 cm SL male/unsexed  Known from the Amazon River (Ref. 37059). + 
Crenuchidae Characidium stigmosum Melo & Buckup, 2002 Fr native   4.25 cm SL male/unsexed  Type locality, Goiás State, mun. Cavalcante, Goiás, small stream tributary of córrego, Ave Maria, near Santo Antônio farm headquarters, 14 km north of Cavalcante, MZUSP 40804 (holotype of Characidium stigmosum, 3.37 cm SL, male) (Ref. 46824). Also Ref. 37059. from the tributaries of rio das Almas, a left bank tributary of rio Paranã in Goiás State (Ref. 46824). Also Ref. 37059. - 
Crenuchidae Characidium summum Zanata & Ohara, 2015 Fr endemic    4.23 cm SL male/unsexed  Only known from upper rio Pacaás Novos, a tributary of rio Mamoré, rio Madeira basin, Rondônia State, Brazil (Ref. 104900). - 
Crenuchidae Characidium tenue (Cope, 1894) Fr native  Canivete (Portuguese)  5.60 cm SL male/unsexed  Found in the Uruguay River and Laguna dos Patos basins (Ref. 37059). Type locality, upper Rio Jacuhy, Rio Grande do Sul, Brazil (Ref. 26282). - 
Crenuchidae Characidium timbuiense Travassos, 1946 Fr native   5.69 cm SL male/unsexed  Known from Timbuí River basin in Espírito Santo (Ref. 37059). Type locality: Córrego Valsungana, trib. Of Rio Timbui, near Santa Tereza, Estado do Espíritu Santo, Brazil, elev. 785 m (Ref. 26282). - 
Crenuchidae Characidium travassosi Melo, Buckup & Oyakawa, 2016 Fr native   5.63 cm SL male/unsexed  Type locality of the holotype Characidium travassosi: rio Iguacu basin, a small tributary of rio Jordao, rio das Torres (Ref. 128858). - 
Crenuchidae Characidium vestigipinne Buckup & Hahn, 2000 Fr endemic    5.10 cm SL male/unsexed  Known only from the type locality in the headwaters of Caraguatá River, upper Uruguay River drainage (Ref. 37059). Type locality: headwaters of Rio Caraguatá, state of Rio Grande do Sul (Ref. 36884). - 
Crenuchidae Characidium vidali Travassos, 1967 Fr native   6.40 cm SL male/unsexed  Known from northeastern tributaries of Guanabara Bay in Rio de Janeiro (Ref. 37059). Type locality: Rio Soberbo, Barreira (Parque Nacional da Serra dos Orgaos), Rio de Janeiro, Brazil, elev. 400 m (Ref. 26282). - 
Crenuchidae Characidium xanthopterum Silveira, Langeani, da Graça, Pavanelli & Buckup, 2008 Fr native   4.73 cm SL male/unsexed  Found in the tributaries of the rio Paranaíba drainage, upper rio Paraná basin, and tributaries to the upper rio Tocantins basin in Goiás (Ref. 76854). - 
Crenuchidae Characidium xavante da Graça, Pavanelli & Buckup, 2008 Fr native   2.82 cm SL male/unsexed  Found in Rio Culuene watershed in the upper Rio Xingu drainage, Mato Grosso (Ref. 75787). - 
Crenuchidae Characidium zebra Eigenmann, 1909 Fr native  Piquira (Portuguese)   7.40 cm SL male/unsexed  Occurs in the Pardo River, upper Paraná River basin, southeastern Brazil (Ref. 27745). Recorded from Córrego Barreiro (Ref. 53011). + 
Characidae Charax awa Guimarães, Brito, Ferreira & Ottoni, 2018 Fr native   12.00 cm SL male/unsexed  Found in the Rio Mearim, Rio Munim and Rio Turiaçu basins, Maranhão state, northeastern Brazil (Ref. 117313). - 
Characidae Charax caudimaculatus Lucena, 1987 Fr native  Saicanga (Portuguese)   9.70 cm SL male/unsexed  Known from the Madeira (Ref. 36811) and Acre River basins (Ref. 97592). - 
Characidae Charax condei (Géry & Knöppel, 1976) Fr native   5.38 cm SL male/unsexed  Known from Negro River basin (Ref. 36811). Type locality, Rio Negro (Ref. 33021). Also Ref. 1672. - 
Characidae Charax delimai Menezes & Lucena, 2014 Fr native   10.20 cm SL male/unsexed ;12.10 cm SL female  Known from the Rio Tiquié, rio Negro basin (Ref. 96861) - 
Characidae Charax gibbosus (Linnaeus, 1758) Fr native  Giboso (Portuguese), Saicanga (Portuguese)   14.40 cm TL male/unsexed    + 
Characidae Charax hemigrammus (Eigenmann, 1912) Fr native   3.30 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36811). - 
Characidae Charax leticiae Lucena, 1987 Fr native  Saicanga (Portuguese)   10.00 cm SL male/unsexed  Found in the Uruguay River (Ref. 79585). Museum: near Posto de Trocará, igarapé Urubu, Rio Tocantins, Pará, MZUSP 28660 (holotype of C. leticiae, 7.6 cm SL) (Ref. 27925). Also Ref. 36811. + 
Characidae Charax macrolepis (Kner, 1858) Fr native   9.50 cm SL male/unsexed  Known from Guaporé River basin, upper Madeira River drainage (Ref. 36811). - 
Characidae Charax michaeli Lucena, 1989 Fr native   18.50 cm SL male/unsexed  Known from the Branco River basin (Ref. 36811). Museum: Rio Branco (in front of ilha de Maraca), Igarapé do Cujobim, Roraima, MZUSP 37276 (holotype, 11.3 cm SL) (Ref. 27925). - 
Characidae Charax niger Lucena, 1989 Fr native   12.80 cm SL male/unsexed  Found in coastal rivers of Amapá State (Ref. 36811). Museum: Rio Amapá (canal do rio), Cachoeira Grande, Amapá, MZUSP 33422 (holotype, 12.4 cm SL) (Ref. 27925). - 
Characidae Charax pauciradiatus (Günther, 1864) Fr native  Cacunda (Portuguese)  10.10 cm SL male/unsexed  Known from the lower Amazon River basin (Ref. 36811). Present in the Oyapock River which forms the border between French Guiana and Brazil (Ref. 12225). + 
Characidae Charax rupununi Eigenmann, 1912 Fr native   4.50 cm SL male/unsexed   - 
Characidae Charax stenopterus (Cope, 1894) Fr native  Corcunda (Portuguese), Lambari-vidro (Portuguese)  9.40 cm SL male/unsexed  Also Ref. 36811. + 
Characidae Charax tectifer (Cope, 1870) Fr native    14.40 cm SL male/unsexed  Found in Purus and Acre River basins (Ref. 97592). - 
Characidae Charax unimaculatus Lucena, 1989 Fr native   8.60 cm SL male/unsexed  Known from the middle Amazon River basin (Ref. 36811). Museum: Lago Manacapuru, Amazonia, MZUSP 6634 (holotype, 6.5 cm SL) (Ref. 27925). - 
Heptapteridae Chasmocranus bleekeri (Boeseman, 1953) Fr native   15.50 cm SL male/unsexed  Occurs in the State of Amapá (Ref. 36914). + 
Heptapteridae Chasmocranus brachynemus Gomes & Schubart, 1958 Fr endemic  Bagrinho (Portuguese)   13.10 cm SL male/unsexed  Known from Mogi Guaçu River basin in upper Paraná River drainage (Ref. 36914). - 
Heptapteridae Chasmocranus brevior Eigenmann, 1912 Fr native    7.90 cm SL male/unsexed    + 
Heptapteridae Chasmocranus longior Eigenmann, 1912 Fr native   17.00 cm SL male/unsexed  Occurs in the Negro and Xingu River basins (Ref. 36914). + 
Heptapteridae Chasmocranus lopezae Miranda Ribeiro, 1968 Fr endemic   5.40 cm TL male/unsexed  Known from undetermined stream in São Paulo (Ref. 36914). - 
Heptapteridae Chasmocranus truncatorostris Borodin, 1927 Fr endemic  Bagre do banhado (Portuguese), Jundiá pintado (Portuguese)  11.00 cm SL male/unsexed  Known from Colonia Hansa Joinvile (=Joinville), Santa Catarina Province (Ref. 6868, 36914). - 
Loricariidae Chauliocheilos saxatilis Martins, Andrade, Rosa & Langeani, 2014 Fr native   4.88 cm SL male/unsexed  Found only in the headwaters of rio Itamarandiba, upper rio Jequitinhonha drainage in southeastern Brazil (Ref. 98819). - 
Pimelodidae Cheirocerus eques Eigenmann, 1917 Fr native  Mandi de raso (Portuguese), Mandi do olhão (Portuguese), Mandi manteiga (Portuguese)    Known from the Amazon River basin (Ref. 36506). - 
Pimelodidae Cheirocerus goeldii (Steindachner, 1908) Fr native  Mandi (Portuguese)   15.20 cm SL male/unsexed  Known from Purus River basin (Ref. 36506). Type locality: Rio Purus, Brazil (Ref. 26282, 6868). - 
Characidae Cheirodon ibicuhiensis Eigenmann, 1915 Fr native  Lambari (Creole, Portuguese)  4.19 cm SL male/unsexed  Type locality: Cacequy [Cacequi], Rio Ibicuí, Rio Grande do Sul, Brazil (Ref. 26282). + 
Characidae Cheirodon interruptus (Jenyns, 1842) Fr native  Lambari (Creole, Portuguese)   5.78 cm SL male/unsexed ;6.00 cm TL female  Recorded from the Patos lagoon (Ref. 58359). + 
Characidae Cheirodon jaguaribensis Fowler, 1941 Fr native  Piabinha (Portuguese)  3.80 cm SL male/unsexed  Known from the Jaguaribe River basin in northeastern Brazil (Ref. 48602). - 
Characidae Cheirodon parahybae Eigenmann, 1915 Fr native  Lambari (Creole, Portuguese)  3.90 cm TL male/unsexed  Known from Paraíba do Sul River basin (Ref. 37055). - 
Chilodontidae Chilodus gracilis Isbrücker & Nijssen, 1988 Fr native   6.40 cm SL male/unsexed  Occurs in central portions of the Amazon River basin (Ref. 37477). + 
Chilodontidae Chilodus punctatus Müller & Troschel, 1844 Fr native  Cabeça para baixo (Portuguese), Quilodos (Portuguese)   18.00 cm TL male/unsexed  Found in the Acre river basin (Ref. 97592). + 
Chilodontidae Chilodus zunevei Puyo, 1946 Fr native   7.70 cm SL male/unsexed   + 
Characidae Chrysobrycon eliasi Vanegas-Ríos, Azpelicueta & Ortega, 2011 Fr native    3.99 cm SL male/unsexed ;4.35 cm female  Found in the Purus and Acre River basins (Ref. 97592). - 
Cichlidae Cichla jariina Kullander & Ferreira, 2006 Fr native    34.00 cm SL male/unsexed  Type locality, Rio Jari downstream of Cachoeira Santo Antonio, State of Pará, INPA 3504 (holotype of Cichla jariina, 34 cm SL, adult male ). Known only from the Rio Jari, in the region of Cachoeira Itacari and Cachoeira Santo Antonio (Ref. 57716). + 
Cichlidae Cichla kelberi Kullander & Ferreira, 2006 Fr native  Tucunaré amarela (Portuguese), Tucunaré comum (Portuguese)   58.50 cm SL male/unsexed 21.5 TL Type locality, Pará: Tucurui, MZUSP 92397 (holoype of Cichla kelberi, 27.6 cm SL). Known from the Rio Araguaia drainage and the lower Rio Tocantins drainage. Introduced in reservoirs in Rio Grande do Norte, Minas Gerais and Ceará (as C. monoculus, cited in Chellappa et al., 2003; as C. ocellaris cited in Fontenele, 1948, ); in the Rio Paraíba do Sul (State of Rio de Janeiro); and, the Rio Paraná. Tucunaré amarela was listed from the Itaipu, Porto Primavera, Jupiá, Três Irmãos, Ilha Solteira, São Simão, Porto Colômbia, Volta Grande, Jaguara, Estreito, Promissão, Igaratá and Paraibuna dams in the Brazilian Paraná basin, the Funil and Ribeirão das Lajes dams in the Rio Paraíba do Sul drainage, the Xingó dam in the Rio São Francisco drainage, the Pacoti-Riachão dam near Fortaleza in Ceará, the Serra da Mesa dam in the Rio Tocantins drainage (Ref. 57716). + 
Cichlidae Cichla melaniae Kullander & Ferreira, 2006 Fr native    36.00 cm TL male/unsexed  Restricted to the Lower Rio Xingu drainage: Balneário do Pedral on the Rio Xingu, Gorotire, at the lower course of Rio Fresco; and Cachoeira do Espelho. Type locality, Cachoeira do Espelho, MZUSP 92400 (holotype of Cichla melaniae, 23 cm SL, adult female) (Ref. 57716). + 
Cichlidae Cichla mirianae Kullander & Ferreira, 2006 Fr native    52.00 cm SL male/unsexed  Type locality, forest pool in Rio Arinos, Município Porto dos Gauchos, Mato Grosso, MZUSP 92399 (holotype of Cichla mirianae, 23.6 cm SL, adult female). Known from the upper Rio Tapajós drainage, in the Juruena and Teles Pires rivers, and from the middle and upper Rio Xingu drainage, in the Fresco, Batovi, Culuene and Suiá-Missu rivers (Ref. 57716). + 
Cichlidae Cichla monoculus Agassiz, 1831 Fr, Fi native  Tucunaré açu (Portuguese), Tucunaré (Portuguese)   70.00 cm SL male/unsexed 18 TL Known from Tabatinga to the Marajó island, including lower parts of the Tefé, Trombetas and Tapajós rivers (Ref. 57716). Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). + 
Cichlidae Cichla nigromaculata Jardine & Schomburgk, 1843 Fr native   26.25 cm SL male/unsexed  Type locality, Rio Negro and Padauiri (Ref. 57716). + 
Cichlidae Cichla ocellaris Bloch & Schneider, 1801 Fr, Br questionable  Tucunaré açu (Portuguese), Furiba (Portuguese), Peixe moeda (Portuguese), Peixe zebra (Portuguese), Pitanga (Portuguese), Tucunaré (Portuguese), Tucunaré comum (Portuguese)   74.00 cm TL male/unsexed  Outside distributional range, occurrence needs confirmation. + 
Cichlidae Cichla orinocensis Humboldt, 1821 Fr native  Tucunaré (Portuguese), Tucunaré miri (Portuguese)   61.70 cm SL male/unsexed  Known from the Amazon River basin in the Negro River asin (Ref. 36377). + 
Cichlidae Cichla pinima Kullander & Ferreira, 2006 Fr native  Tucunaré pinima (Portuguese)   52.00 cm SL male/unsexed  Type locality, Km 30, Rio Curuá-Una, Pará, INPA 691 (holotype of Cichla pinima, 30 cm SL, adult male). Known from Lower Rio Tapajós, Rio Curuá-Una, lower Rio Xingu, lower Rio Tocantins, and Rio Capim (Fig. 75); uncertain localities in southern Amapá and Rio Arapiuns, introduced in Rio Paraguaçu in eastern Brazil, and probably elsewhere in northeastern Brazil (Ref. 57716). + 
Cichlidae Cichla piquiti Kullander & Ferreira, 2006 Fr native  Tucunaré (Portuguese), Tucunaré azul (Portuguese)   48.00 cm TL male/unsexed ;38.50 cm TL female  Type locality, Rio Itacaiúnas at Caldeirão, Pará, MZUSP 40296 (holotype of Cichla piquiti, 21.9 cm SL, young male). Natural occurrences are recorded from the lower (Rio Itacaiunas, Marabá, Itupiranga), and upper Rio Tocantins (Rio Paranã), as well as in the Araguaia drainage (Cocalinho and Rio das Mortes). + 
Cichlidae Cichla pleiozona Kullander & Ferreira, 2006 Fr native    44.20 cm SL male/unsexed    + 
Cichlidae Cichla temensis Humboldt, 1821 Fr, Fi native  Tucunaré (Portuguese), Tucunaré açú (Portuguese), Tucunaré comum (Portuguese), Tucunaré paca (Portuguese), Tucunaré pinima (Portuguese), Tucunaré tinga (Portuguese)   99.00 cm TL male/unsexed  Restricted to blackwater rivers and their tributaries of many localities along the Rio Negro. Specimens from Rio Jamari (INPA 3493) and a small specimen from Lago Genipapo (INPA uncat.) on the Rio Aripuanã are questionably referred to C. temensis (Ref. 57716). + 
Cichlidae Cichla thyrorus Kullander & Ferreira, 2006 Fr native    43.00 cm SL male/unsexed  Type locality, Igarapé Caxipacoré, Pará, INPA 3503 (holotype of Cichla thyrorus, 35.5 cm SL) (Ref. 57716). Known from the upstream of the falls, Rio Trombetas near Cachoeira Porteira (Ref. 57716). + 
Cichlidae Cichla vazzoleri Kullander & Ferreira, 2006 Fr native    41.00 cm SL male/unsexed  Type locality, Area Shell-Alcoa, lower Rio Trombetas, Rio Trombetas drainage, Pará, INPA 3501(holotype of Cichla vazzoleri, 29.5 cm SL, adult male). Known from the middle Rio Uatumã and lower Rio Trombetas including but not above the Cachoeira Porteira, to the Oriximiná region at the mouth of the Rio Cuminá (Ref. 57716). + 
Cichlidae Cichlasoma amazonarum Kullander, 1983 Fr, Fi native  Acará (Portuguese)  13.50 cm SL male/unsexed  Recorded from Machado river basin (Ref. 97589). Found in fish markets in Santarám (Ref. 12202). Also Ref. 12251, 36377. + 
Cichlidae Cichlasoma araguaiense Kullander, 1983 Fr endemic    15.50 cm SL male/unsexed ;13.30 cm SL female  Known from the Amazon River basin in Tocantins and upper Xingu River basins (Ref. 36377). Found in the Araguaia and Ilha do Bananal (Ref. 12251). + 
Cichlidae Cichlasoma bimaculatum (Linnaeus, 1758) Fr native  Acará (Portuguese), Acará-cascudo (Portuguese) common (usually seen) 12.30 cm SL male/unsexed ;30.00 cm TL female  Known from the Branco River system (Ref. 26372). + 
Cichlidae Cichlasoma boliviense Kullander, 1983 Fr native    10.70 cm SL male/unsexed   + 
Cichlidae Cichlasoma dimerus (Heckel, 1840) Fr native  Acará (Portuguese), Cará (Portuguese)   11.70 cm SL male/unsexed  Known from the Paraná River basin, in the Paraguay River drainage (Ref. 36377). Type locality: Rio Cuiabá, Mato Grosso, Brazil (Ref. 12251, 12965). + 
Cichlidae Cichlasoma orientale Kullander, 1983 Fr endemic  Acará (Portuguese), Acará comum (Portuguese)   13.60 cm SL male/unsexed 10 TL Occurs in Ceará, Pernambuco, Rio Grande do Norte and Paraíba (Ref. 36377). Found in large quantities in Juazeiro do Norte, Ceara and along the road from Juazeiro to Recife and Fortaleza (Ref. 12251). Type locality: Pentecoste, Rio Curu system, Ceará, Brazil (Ref. 12965). + 
Cichlidae Cichlasoma paranaense Kullander, 1983 Fr endemic    9.50 cm SL male/unsexed 4.7 TL Known from the upper Paraná River drainage above Guaira (Ref. 36377). Type locality: Tres Lagoas, on left bank of Rio Sucuriú, Mato Grosso do Sul, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Cichlasoma portalegrense (Hensel, 1870) Fr endemic  Acará verde (Portuguese), Cará (Portuguese)   12.90 cm TL male/unsexed  Known from Laguna dos Patos basin and Tramandaí River basin in Rio Grande do Sul (Ref. 36377). Also Ref. 12251. + 
Cichlidae Cichlasoma sanctifranciscense Kullander, 1983 Fr endemic  Acará (Portuguese), Cará (Portuguese)   8.79 cm SL male/unsexed  Known from São Francisco, Parnaíba and Capivara River basins (Ref. 36377 ). Common from Brasilia to the western side of the Chapada Diamantina (Ref. 12251). Type locality: Lagoa Viana, Rio Sao Franciso system, Bahia, Brazil (Ref. 12965). + 
Cichlidae Cichlasoma zarskei Ottoni, 2011 Fr native   9.96 cm SL male/unsexed   - 
Cyclopsettidae Citharichthys uhleri Jordan, 1889 Fr native   14.00 cm SL male/unsexed   + 
Clariidae Clarias gariepinus (Burchell, 1822) Fr introduced  Bagre-africano (Portuguese) fairly common (chances are about 50%) 170 cm TL male/unsexed  Introduced in the Guaraguaçu River basin (Ref. 57722, 94815) and Urugay River (Ref. 79585). The species has become widespread in Guaraguaçu as per sampling done November 2002 and May-September 2004 using gill nests, longlines, cast nets, beach seines and fish traps. Twenty-three specimens, lengths ranging from 33.4-78.5 cm including 3 mature females were caught (Ref. 57722). Also ref. 13686. + 
Triportheidae Clupeacharax anchoveoides Pearson, 1924 Fr native    6.55 cm SL male/unsexed  Found in Pantanal (Ref. 81048). Also Ref. 38378. - 
Poeciliidae Cnesterodon brevirostratus Rosa & Costa, 1993 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  4.39 cm SL male/unsexed  Known from Rio Grande do Sul (Ref. 30833). Found in the upper Pelotas and Canoas River basins in Uruguay River drainage; Jacuí River as well as the headwaters of the Maquiné River in the Tramandaí River basins and the headwaters of Itajaí-Açu River basin (Ref. 50894). - 
Poeciliidae Cnesterodon carnegiei Haseman, 1911 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  2.97 cm SL male/unsexed ;3.50 cm female  Known from the upper Iguaçu River and its upper tributaries (Ref. 50894). Also Ref. 26130. + 
Poeciliidae Cnesterodon decemmaculatus (Jenyns, 1842) Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)   3.55 cm SL male/unsexed ;4.50 cm TL female  Recorded from the Patos lagoon (Ref. 58359). + 
Poeciliidae Cnesterodon hypselurus Lucinda & Garavello, 2001 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  3.05 cm SL male/unsexed  Known from Paranapanema River basin (Ref. 50894). + 
Poeciliidae Cnesterodon iguape Lucinda, 2005 Fr native   2.24 cm SL male/unsexed ;2.49 cm SL female  Known from Apiaí, creek on headwaters of rio Iporanga in São Paulo (Ref. 57154). + 
Poeciliidae Cnesterodon omorgmatos Lucinda & Garavello, 2001 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  3.05 cm SL male/unsexed  Known from the Iguacu River basin (Ref. 50894). - 
Poeciliidae Cnesterodon septentrionalis Rosa & Costa, 1993 Fr native   3.00 cm SL male/unsexed  Known from a swamp near the Córrego do Rancho fountainhead, Mato Grosso (Ref. 30833). Found in the upper Araguaia River basin (Ref. 50894). + 
Tetraodontidae Colomesus asellus (Müller & Troschel, 1849) Fr native    12.80 cm SL male/unsexed  Known from the Amazon River including tributaries Araguaia and Guaporé Rivers (Ref. 79673). + 
Tetraodontidae Colomesus tocantinensis Amaral, Brito, Silva & Carvalho, 2013 Fr native   3.49 cm SL male/unsexed  Type locality of Colomesus tocantinensis, Tocantins River near Porto Nacional, State of Tocantins (Ref. 122317). - 
Serrasalmidae Colossoma macropomum (Cuvier, 1816) Fr, Fi, Aq, Rstr native  Ruelo (Portuguese), Bocó (Portuguese), Pirapitinga (Portuguese), Tambaqui (Portuguese), Tambaqui branco (Portuguese) common (usually seen) 108 cm TL male/unsexed  Aquaculture: also experimental. Also Ref. 9987. + 
Apteronotidae Compsaraia compsa (Mago-Leccia, 1994) Fr native   33.90 cm TL male/unsexed  Found in the Negro River basin (Ref. 36886). - 
Apteronotidae Compsaraia iara Bernt & Albert, 2017 Fr native   23.50 cm TL male/unsexed  Known from the Amazon River and near the mouths of its larger tributaries (Ref. 115978). - 
Apteronotidae Compsaraia samueli Albert & Crampton, 2009 Fr native   22.60 cm SL male/unsexed   + 
Characidae Compsura heterura Eigenmann, 1915 Fr native  Piabinha (Creole, Portuguese)  3.80 cm TL male/unsexed  Known from São Francisco and Parnaíba River basins, and Atlantic versant rivers of Ceará, Rio Grande do Norte, Paraíba and Pernambuco (Ref. 37055). + 
Pimelodidae Conorhynchos conirostris (Valenciennes, 1840) Fr native  Pirá (Portuguese), Pirá-tamanduá (Portuguese)   53.50 cm SL male/unsexed  Occurs in Rio São Fransisco (Ref. 6868). Regarded as threatened in the state of Minas Gerais (Ref. 26603). + 
Lebiasinidae Copeina guttata (Steindachner, 1876) Fr native  Copeína rubi (Portuguese)  7.60 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Lebiasinidae Copella arnoldi (Regan, 1912) Fr native  Piratanta (Portuguese), Pirá tantan (Portuguese), Splashing tetra (English)   3.36 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Lebiasinidae Copella carsevennensis (Regan, 1912) Fr native   5.70 cm TL male/unsexed   + 
Lebiasinidae Copella compta (Myers, 1927) Fr native   5.06 cm SL male/unsexed  Recorded from the Rio Negro. Also Ref. 37104. + 
Lebiasinidae Copella eigenmanni (Regan, 1912) Fr native   3.60 cm SL male/unsexed  Museum: Marapanin, MZUSP uncat. Known from Para. + 
Lebiasinidae Copella meinkeni Zarske & Géry, 2006 Fr native   4.54 cm SL male/unsexed  Known from the rio Negro (Ref. 77043). + 
Lebiasinidae Copella metae (Eigenmann, 1914) Fr native   3.40 cm SL male/unsexed   + 
Lebiasinidae Copella nattereri (Steindachner, 1876) Fr, Fi native    4.50 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Lebiasinidae Copella nigrofasciata (Meinken, 1952) Fr native    4.50 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Lebiasinidae Copella vilmae Géry, 1963 Fr, Fi native   4.50 cm SL male/unsexed  Recorded from the Upper Amazon (Ref. 598, 37104). + 
Trichomycteridae Copionodon elysium de Pinna, Burger & Zanata, 2018 Fr native   7.15 cm SL male/unsexed  Type locality of the holotype of Copionodon elysium: Rio Santo Antonio drainage, upper Rio Paraguaçu basin, Bahia (Ref. 118359). - 
Trichomycteridae Copionodon lianae Campanario & de Pinna, 2000 Fr native   6.38 cm SL male/unsexed  Type locality, Rio Grisante (Rio Mucujê basin), Bahia (Ref. 45131). Also Ref. 39970. - 
Trichomycteridae Copionodon orthiocarinatus de Pinna, 1992 Fr native   7.50 cm SL male/unsexed  Known from Mucujê River, tributary of the Paraguaçu River (Ref. 39970). - 
Trichomycteridae Copionodon pecten de Pinna, 1992 Fr native   6.22 cm SL male/unsexed  Known from Mucujê River, tributary of the Paraguaçu River (Ref. 39970). - 
Characidae Coptobrycon bilineatus (Ellis, 1911) Fr native    4.10 cm TL male/unsexed  Found in the upper Tietê River basin (Ref. 38376). + 
Cichlidae Coptodon rendalli (Boulenger, 1897) Fr, Br, Fi introduced  Tilápia (Portuguese), Acará tilápia (Portuguese), Tilápia do congo (Portuguese), Tilápia-rendali (Portuguese)   45.00 cm TL male/unsexed  Recorded in Piracicaba river (Ref. 50076) and Machado River (Ref. 97589). + 
Loricariidae Cordylancistrus platyrhynchus (Fowler, 1943) Fr native    9.50 cm TL male/unsexed   - 
Loricariidae Corumbataia britskii Ferreira & Ribeiro, 2007 Fr native   2.70 cm SL male/unsexed  Found in two streams, Córrego Pedra Azul and Córrego Fazendinha. These steams are both tributaries of Rio Sucuriú, a right tributary of the upper Rio Paraná basin in Mato Grosso do Sul (Ref. 57842). - 
Loricariidae Corumbataia cuestae Britski, 1997 Fr native   3.30 cm SL male/unsexed  Known from the Tietê River basin (Ref. 36885). + 
Loricariidae Corumbataia liliai Silva, Roxo, Souza & Oliveira, 2018 Fr native   2.47 cm SL female  Type locality of the holotype of Corumbataia liliai: Rio Corrente drainage, upper Rio Paraná basin, Córrego da Cachoeira, Goiás (Ref. 118639). - 
Loricariidae Corumbataia lucianoi Silva, Roxo, Souza & Oliveira, 2018 Fr native   2.40 cm SL male/unsexed  Type locality of the holotype of Corumbataia lucianoi: Rio Corrente, upper Rio Paraná basin, Goiás (Ref. 118639). - 
Loricariidae Corumbataia tocantinensis Britski, 1997 Fr native   3.80 cm SL male/unsexed  Known from the Araguaia and Tocantins River basins (Ref. 36885). - 
Loricariidae Corumbataia veadeiros Carvalho, 2008 Fr native   3.68 cm SL male/unsexed  Known from the Rio das Almas and the Ribeirão dos Bois, both of which are tributaries of the Rio Paranã, in the headwaters of the Rio Tocantins basin in Goiás (Ref. 78746). - 
Callichthyidae Corydoras acrensis Nijssen, 1972 Fr endemic    3.00 cm SL male/unsexed  Recorded from Furo do lago Sao Francisco, a tributary at the left bank of the Rio Jurua, upstream of the confuence with the Mao at Cruzeiro do Sul, Estado Acre (Ref. 26041). Found in the Acre and Purus River basins (Ref. 97592). + 
Callichthyidae Corydoras acutus Cope, 1872 Fr native   5.48 cm SL male/unsexed  Recorded from Machado River basin (Ref. 97589). + 
Callichthyidae Corydoras adolfoi Burgess, 1982 Fr native   5.70 cm SL male/unsexed  Known from the Negro River basin (Ref. 37395). Recorded from Sao Gabriel da Cachoeira, a small tributary of the upper Rio Negro (Ref. 26041). + 
Callichthyidae Corydoras aeneus (Gill, 1858) Fr native  Dunda (Portuguese), Camboatazinho (Portuguese), Coridora (Portuguese), Corídora (Portuguese), Enéus (Portuguese), Limpa planta (Portuguese), Sarro (Portuguese), Tamuata (Portuguese)   7.50 cm SL male/unsexed  Found in Córrego Barreiro (Ref. 53011) and Acre River basin (Ref. 97592). + 
Callichthyidae Corydoras agassizii Steindachner, 1876 Fr native  Agassízi (Portuguese)  5.20 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). + 
Callichthyidae Corydoras amandajanea Sands, 1995 Fr native   5.88 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras amapaensis Nijssen, 1972 Fr native   7.00 cm SL male/unsexed  Found in Amapa (Ref. 26041). + 
Callichthyidae Corydoras ambiacus Cope, 1872 Fr, Or native   4.90 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras apiaka Espíndola, Spencer, Rocha & Britto, 2014 Fr native   3.88 cm SL male/unsexed  Found only in the tributaries of the rio Arinos, rio Teles Pires and rio Preto, all clearwater tributaries of the upper rio Tapajós in Mato Grosso State (Ref. 102660). - 
Callichthyidae Corydoras araguaiaensis Sands, 1990 Fr native   3.50 cm SL male/unsexed  Known from the Rio Araguaia (Ref. 26041). + 
Callichthyidae Corydoras arcuatus Elwin, 1938 Fr native  Tabatinga (Portuguese), São Pedro (Portuguese), Sarro (Portuguese)  4.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). + 
Callichthyidae Corydoras areio Knaack, 2000 Fr native  Camboatazinho (Portuguese)  5.00 cm SL male/unsexed  Known from the upper Paraguay River basin (Ref. 37395). - 
Callichthyidae Corydoras armatus (Günther, 1868) Fr native    5.00 cm SL male/unsexed    + 
Callichthyidae Corydoras aurofrenatus Eigenmann & Kennedy, 1903 Fr native      + 
Callichthyidae Corydoras baderi Geisler, 1969 Fr native   4.70 cm SL male/unsexed  Known from the Rio Paru do Oeste, Para (Ref. 26041). + 
Callichthyidae Corydoras benattii Espíndola, Tencatt, Pupo, Villa‐Verde & Britto, 2018 Fr native   3.09 cm SL male/unsexed  Type locality of Corydoras benattii, Mato Grosso, between Canarana and Gaúcha do Norte, Rio Culuene, a tributary to the Rio Xingu. It is known from Rio Xingu and Rio Tapajós basins, Brazilian Amazon. In the Rio Xingu basin, it is also known in Pará State from the Rio Fresco sub drainage (Rio Trairão and Igarapé Manguari), middle Rio Xingu and from the lower Rio Xingu basin near Altamira. In the Rio Tapajós basin, it occurs in the Rio Peixoto de Azevedo, a tributary to the Rio Teles Pires, Mato Grosso and from Rio Cururu, a tributary to the Rio São Manuel, Pará (Ref. 122129). + 
Callichthyidae Corydoras bifasciatus Nijssen, 1972 Fr native   5.15 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). - 
Callichthyidae Corydoras blochi Nijssen, 1971 Fr native   4.90 cm SL male/unsexed  Known from Amazonas and Branco drainages (Ref. 26041). + 
Callichthyidae Corydoras bondi Gosline, 1940 Fr native   4.70 cm SL male/unsexed  Found in Machado River basin (Ref. 97589). + 
Callichthyidae Corydoras britskii (Nijssen & Isbrücker, 1983) Fr native   8.80 cm SL male/unsexed  Known from the upper Paraguay River basin (Ref. 37395). Also Ref. 26041. + 
Callichthyidae Corydoras brittoi Tencatt & Ohara, 2016 Fr native   3.90 cm SL male/unsexed  Type locality of the holotype of Corydoras brittoi: rio Madeira basin, rio Aripuanã drainage, Mato Grosso (Ref. 128862). - 
Callichthyidae Corydoras burgessi Axelrod, 1987 Fr native   4.80 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras carlae Nijssen & Isbrücker, 1983 Fr native    5.35 cm SL male/unsexed    + 
Callichthyidae Corydoras caudimaculatus Rössel, 1961 Fr, Or native   4.15 cm SL male/unsexed  Known from the upper Rio Guapore (Ref. 26041). + 
Callichthyidae Corydoras cervinus Rössel, 1962 Fr, Or native    4.90 cm SL male/unsexed  Found in the main stream of the upper Rio Guapore, Rondonia (Ref. 26041). Not common in the aquarium trade (Ref. 26041). + 
Callichthyidae Corydoras cochui Myers & Weitzman, 1954 Fr native   2.50 cm SL male/unsexed  Recorded from the Rio Araguaya (Goiaz Province), Santa Maria, Novo (Ref. 26041). + 
Callichthyidae Corydoras condiscipulus Nijssen & Isbrücker, 1980 Fr native   5.10 cm SL male/unsexed   + 
Callichthyidae Corydoras crimmeni Grant, 1997 Fr native   4.00 cm SL male/unsexed  Known from the Negro River basin (Ref. 37395). Type locality, aquarium specimen, said to be from Brazil, Roraima State, near the city of Boa Vista, possibly from the Rio Branco (Ref. 34116). - 
Callichthyidae Corydoras crypticus Sands, 1995 Fr native   4.50 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras davidsandsi Black, 1987 Fr native   4.40 cm SL male/unsexed  Known from the Negro River basin (Ref. 37395). Type locality, Rio Unini (Ref. 34117). + 
Callichthyidae Corydoras difluviatilis Britto & Castro, 2002 Fr native  Coridora (Portuguese)  4.73 cm SL male/unsexed  Recorded from the upper rio Paranaíba and upper rio Grande basins, rio Paraná system, and rio Jequitaí, rio Preto, and headwaters of rio da Prata, São Francisco system, in the states of Goiás, Minas Gerais and São Paulo (Ref. 46825). Also Ref. 37395. + 
Callichthyidae Corydoras duplicareus Sands, 1995 Fr native   4.00 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras ehrhardti Steindachner, 1910 Fr native    4.68 cm SL male/unsexed  Found in coastal rivers in Santa Catarina and Paraná and the Iguaçu River basin (Ref. 37395). Recorded from mountain streams near Joinville in Estado Parana and Jaragua in Estado Sao Paulo (Ref. 26041). + 
Callichthyidae Corydoras elegans Steindachner, 1876 Fr native    5.10 cm SL male/unsexed  Found in the central Amazon region near Tefe and the Rio Ampiyacu (Ref. 26041). Recorded from the Acre, Purus (Ref. 97592) and Machado River basins (Ref. 97589). + 
Callichthyidae Corydoras ellisae Gosline, 1940 Fr native  Camboatazinho (Portuguese)  5.00 cm SL male/unsexed  Found in Pantanal (Ref. 81048). + 
Callichthyidae Corydoras ephippifer Nijssen, 1972 Fr, Or native   4.95 cm SL male/unsexed  Found in creeks of Rio Amapari, Amapa (Ref. 26041). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras eques Steindachner, 1876 Fr native  Corídora (Portuguese)  4.80 cm SL male/unsexed  Found in the Amazon River near Tefe and Cudajas (Ref. 26041). + 
Callichthyidae Corydoras evelynae Rössel, 1963 Fr native   4.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). Found in the upper Rio Solimoes, Amazonas (Ref. 26041). - 
Callichthyidae Corydoras eversi Tencatt & Britto, 2016 Fr native   4.53 cm SL male/unsexed  Known from its type locality, an unnamed stream tributary to the rio Araguaia in Montes Claros de Goiás, Goiás (Ref. 109933). - 
Callichthyidae Corydoras flaveolus Ihering, 1911 Fr native  Rouquinho (Portuguese)  3.82 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 37395). Recorded from the tributaries to Rio Piracicaba above Salto, Sao Paulo (Ref. 26041). + 
Callichthyidae Corydoras froehlichi Tencatt, Britto & Pavanelli, 2016 Fr native   5.15 cm SL male/unsexed  Type locality of Corydoras froehlichi, Rio Grande do Sul, Esmeralda, rio Pelotas. Known from the upper rio Uruguai basin, from the rivers Canoas, do Peixe and Pelotas. It may be widespread in other tributaries to the rio Pelotas (Ref. 129023). Status of threat: Least Concern. - 
Callichthyidae Corydoras garbei Ihering, 1911 Fr native  Coridora (Portuguese), Tamoatá (Portuguese)  3.88 cm SL male/unsexed  Known from the Rio Sao Francisco, Bahia (Ref. 26041). Also Ref, 37395. - 
Callichthyidae Corydoras gossei Nijssen, 1972 Fr, Or native   5.50 cm SL male/unsexed  Known from the Rio Mamore system in Rondonia (Ref. 26041). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras gracilis Nijssen & Isbrücker, 1976 Fr native   2.32 cm SL male/unsexed  Recorded from the Rio Madeira within 100 miles of Porto Velho and from a tributary of Rio Tapajos, 66.5 km west of Itaituba, Estado Para (Ref. 26041). + 
Callichthyidae Corydoras griseus Holly, 1940 Fr, Or native   4.20 cm SL male/unsexed  Recorded from small side streams in the vicinity of the Amazon River (Ref. 26041). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras gryphus Tencatt, Britto & Pavanelli, 2014 Fr native   3.50 cm SL male/unsexed  Found in the lower rio Paraná, near Itaipu dam (Ref. 95506). - 
Callichthyidae Corydoras guapore Knaack, 1961 Fr, Or native   4.10 cm SL male/unsexed  Occurs in the Guaporé River (Ref. 26041). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras haraldschultzi Knaack, 1962 Fr, Or native   5.90 cm SL male/unsexed  Occurs in the Rio Tocantins, Rio Araguaia and the upper Rio Guapore, a border river between Brazil and Bolivia (Ref. 26041). Exported to North America as an aquarium fish (Ref 4537). + 
Callichthyidae Corydoras hastatus Eigenmann & Eigenmann, 1888 Fr native  Camboatazinho (Portuguese), Corídora anã (Portuguese)   2.40 cm SL male/unsexed    + 
Callichthyidae Corydoras hephaestus Ohara, Tencatt & Britto, 2016 Fr native   3.34 cm SL male/unsexed  Type locality of holotype Corydoras hephaestus, Tributary of Igarapé Piracolina, near road BR-364, upper Rio Machado, Rio Madeira basin, Vilhena, Rondônia State, Brazil. - 
Callichthyidae Corydoras imitator Nijssen & Isbrücker, 1983 Fr native   5.56 cm SL male/unsexed  Known from the upper Rio Negro (Sao Gabriel da Cachoeira) (Ref. 26041). + 
Callichthyidae Corydoras incolicana Burgess, 1993 Fr native   5.21 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras julii Steindachner, 1906 Fr native  Coridora (Portuguese), Corídora leopardo (Portuguese), Leopardo (Portuguese)   5.20 cm SL male/unsexed  Known from the lower Amazon River and coastal rivers in northeastern Brazil (Ref. 37395). + 
Callichthyidae Corydoras kanei Grant, 1998 Fr native   3.80 cm SL male/unsexed  Known from the Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras lacerdai Hieronimus, 1995 Fr native   3.36 cm SL male/unsexed  Type locality, Rio Ribeira da Terra Firme, between Canavieiras and Ilheus, se. Bahia (Ref. 27251). - 
Callichthyidae Corydoras lacrimostigmata Tencatt, Britto & Pavanelli, 2014 Fr native   3.80 cm SL male/unsexed  Found in the rio Ivaí basin, a tributary of the rio Paraná, in the State of Paraná (Ref. 95501). - 
Callichthyidae Corydoras latus Pearson, 1924 Fr misidentification   5.20 cm SL male/unsexed  Occurrence in this country not supported by R. Reis; probably a misidentification. - 
Callichthyidae Corydoras leopardus Myers, 1933 Fr native   6.10 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). Occurs in coastal waters around Maracana (north from Belem), Para (Ref. 26041). + 
Callichthyidae Corydoras longipinnis Knaack, 2007 Fr questionable   6.11 cm SL male/unsexed  As Corydoras cf. longipinnis from río dos Sinos. Salto Santiago reservoir and río Tibagi (Ref. 129023). + 
Callichthyidae Corydoras lymnades Tencatt, Vera-Alcaraz, Britto & Pavanelli, 2013 Fr native   2.97 cm SL male/unsexed  Found in the upper and middle rio São Francisco basin, from headwater streams in the Minas Gerais State to the main channel of the river in the Bahia State, northeastern Brazil (Ref. 93812). - 
Callichthyidae Corydoras maculifer Nijssen & Isbrücker, 1971 Fr, Or native   5.90 cm SL male/unsexed  Known from the upper Araguaia River basin (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). - 
Callichthyidae Corydoras melanistius Regan, 1912 Fr native    5.10 cm SL male/unsexed   + 
Callichthyidae Corydoras melini Lönnberg & Rendahl, 1930 Fr, Or native   5.00 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras multimaculatus Steindachner, 1907 Fr native  Coridora (Portuguese), Maria da serra (Portuguese), Sarro (Portuguese)  5.10 cm SL male/unsexed  Known from a tributary to the Rio Preto near Santa Rita de Cassia (Ref. 26041). Also Ref. 37395. + 
Callichthyidae Corydoras narcissus Nijssen & Isbrücker, 1980 Fr native   6.50 cm SL male/unsexed  Found in a creek flowing into the Rio Ipixuna, Rio Purus system, Amazonas (Ref. 26041). + 
Callichthyidae Corydoras nattereri Steindachner, 1876 Fr, Or native  Coridoras (Portuguese), São Pedro (Portuguese), Sarro (Portuguese)   5.40 cm SL male/unsexed  Found in coastal rivers in southeastern Brazil from Espírito Santo to Paraná (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras nijsseni Sands, 1989 Fr native   3.00 cm SL male/unsexed  Known from the Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras oiapoquensis Nijssen, 1972 Fr native   4.50 cm SL male/unsexed   + 
Callichthyidae Corydoras ornatus Nijssen & Isbrücker, 1976 Fr native   4.90 cm SL male/unsexed  Found in the tributaries to the Rio Tapajos (Ref. 26041). + 
Callichthyidae Corydoras ourastigma Nijssen, 1972 Fr native   6.00 cm SL male/unsexed  Collected from the Iquiri about 47 km form Rio Branco village, Rio Purus system, Estado Acre (Ref. 26041). + 
Callichthyidae Corydoras paleatus (Jenyns, 1842) Fr native  Limpa-fundo (Portuguese), Cascudinho (Portuguese), Coridora (Portuguese), Corídora (Portuguese), Limpa planta (Portuguese), Limpa vidro (Portuguese), Paleatus (Portuguese), Sarro (Portuguese)   6.60 cm SL male/unsexed ;7.10 cm SL female  Known from the coastal rivers of southern Brazil, Rio Grande do Sul State (Ref. 129023) and found in the Uruguay River (Ref. 79585). + 
Callichthyidae Corydoras parallelus Burgess, 1993 Fr native   5.15 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras pavanelliae Tencatt & Ohara, 2016 Fr native   4.51 cm SL male/unsexed   - 
Callichthyidae Corydoras pinheiroi Dinkelmeyer, 1995 Fr native   5.70 cm SL male/unsexed  Known from western Amazon River basin in Rondônia (Ref. 37395). + 
Callichthyidae Corydoras polystictus Regan, 1912 Fr native  Camboatazinho (Portuguese), Coridora (Portuguese)   3.50 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 37395). Recorded from the tributaries of the eastern Rio Guapore in Mato Grosso (Ref. 26041). + 
Callichthyidae Corydoras pulcher Isbrücker & Nijssen, 1973 Fr, Or native   5.00 cm SL male/unsexed  Known from Purus River basin (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras pygmaeus Knaack, 1966 Fr, Or native   2.10 cm SL male/unsexed  Known from the Madeira River basin (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras rabauti La Monte, 1941 Fr native  Corídora (Portuguese)  5.00 cm SL male/unsexed   + 
Callichthyidae Corydoras reticulatus Fraser-Brunner, 1938 Fr native  São Pedro (Portuguese), Sarro (Portuguese)  6.10 cm SL male/unsexed  Known from the lower Amazon River basin (Ref. 37395). + 
Callichthyidae Corydoras robineae Burgess, 1983 Fr native   4.39 cm SL male/unsexed  Found in Rio Aiuana of the upper Rio Negro (Ref. 26041). + 
Callichthyidae Corydoras robustus Nijssen & Isbrücker, 1980 Fr native   7.12 cm SL male/unsexed  Known from Purus River basin in middle Amazon (Ref. 37395). Found in a creek that runs into the Rio Ipixuna of the Purus system, Estado Amazonas (Ref. 26041). + 
Callichthyidae Corydoras sarareensis Dinkelmeyer, 1995 Fr native   4.40 cm SL male/unsexed  Known from Guaporé River basin (Ref. 37395). - 
Callichthyidae Corydoras schwartzi Rössel, 1963 Fr native  São Pedro (Portuguese), Sarro (Portuguese)  3.90 cm SL male/unsexed  Found near the mouth of the Rio Purus (Ref. 26041). + 
Callichthyidae Corydoras semiaquilus Weitzman, 1964 Fr native   6.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). Collected at Igarape Preto, a small jungle rivulet at the headwaters of the black water creeks that empty into the Rio Solimoes, Amazonas (Ref. 26041). + 
Callichthyidae Corydoras serratus Sands, 1995 Fr native   4.88 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 37395). + 
Callichthyidae Corydoras seussi Dinkelmeyer, 1996 Fr native    6.00 cm SL male/unsexed  Known from the Mamoré River basin (Ref. 37395). + 
Callichthyidae Corydoras similis Hieronimus, 1991 Fr native    3.80 cm SL male/unsexed  Known from Madeira River basin (Ref. 37395). Type locality, Trib. of Rio Madeira, vicinity of Ariqumes, Rondonia (Ref. 27250). + 
Callichthyidae Corydoras sodalis Nijssen & Isbrücker, 1986 Fr native   4.86 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). Recorded from the Rio Solimoes at Benjamin Constant (Ref. 26041). + 
Callichthyidae Corydoras solox Nijssen & Isbrücker, 1983 Fr native   6.25 cm SL male/unsexed  Found in the Rio Oyapok basin in Amapa territory (Ref. 26041). + 
Callichthyidae Corydoras spectabilis Knaack, 1999 Fr native   4.90 cm SL male/unsexed  Known from Guaporé River basin (Ref. 37395). + 
Callichthyidae Corydoras splendens (Castelnau, 1855) Fr native   9.90 cm SL male/unsexed  Found in the Amazon basin (Ref. 26041). + 
Callichthyidae Corydoras steindachneri Isbrücker & Nijssen, 1973 Fr, Or native   5.00 cm SL male/unsexed  Found in coastal rivers in Paraná (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). - 
Callichthyidae Corydoras stenocephalus Eigenmann & Allen, 1942 Fr native   6.35 cm SL male/unsexed  Recorded from Machado river basin (Ref. 97589). + 
Callichthyidae Corydoras sterbai Knaack, 1962 Fr native   6.80 cm SL male/unsexed  Known from the upper Rio Guapore (Ref. 26041). + 
Callichthyidae Corydoras treitlii Steindachner, 1906 Fr, Or native   5.90 cm SL male/unsexed  Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras trilineatus Cope, 1872 Fr native    6.10 cm SL male/unsexed  Known from the Amazon (Ref. 37395) and Machado River basins (Ref. 97589). + 
Callichthyidae Corydoras tukano Britto & Lima, 2003 Fr native   4.14 cm SL male/unsexed  Known only from rio Tiquié and its tributaries in the upper rio Negro basin, Amazonas (Ref. 51470). + 
Callichthyidae Corydoras undulatus Regan, 1912 Fr native  Coridora (Portuguese), Limpa fundo (Portuguese)   4.40 cm SL male/unsexed    + 
Callichthyidae Corydoras urucu Britto, Wosiacki & Montag, 2009 Fr native   2.75 cm SL male/unsexed  Known from the Rio Urucu basin, a tributary of Lago Coari, Rio Solimões system in Coari, Amazonas (Ref. 83456). - 
Callichthyidae Corydoras vittatus Nijssen, 1971 Fr native   3.60 cm SL male/unsexed  Known from the Rio Itapicuru drainage (Ref. 26041). + 
Callichthyidae Corydoras xinguensis Nijssen, 1972 Fr, Or native   3.70 cm SL male/unsexed  Known from the upper Xingu River basin (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Corydoras zawadzkii Tencatt & Ohara, 2016 Fr native   5.00 cm SL male/unsexed  Type locality of the holotype of Corydoras zawadzkii: rio Madeira basin, rio Aripuanã drainage, a tributary to the rio Juma, Mato Grosso State (Ref. 110223). - 
Callichthyidae Corydoras zygatus Eigenmann & Allen, 1942 Fr native    5.60 cm SL male/unsexed  Found in the Purus and Acre River basins (Ref. 97592). + 
Characidae Creagrutus anary Fowler, 1913 Fr native  Anari (Portuguese)   4.50 cm SL male/unsexed  Recorded from the Madeira river. - 
Characidae Creagrutus atrisignum Myers, 1927 Fr native   5.50 cm SL male/unsexed  Known from the Maranhão River basin in Tocantins River drainage (Ref. 38376). - 
Characidae Creagrutus barrigai Vari & Harold, 2001 Fr native   5.33 cm SL male/unsexed  Found in the Amazon River (Ref. 38376). - 
Characidae Creagrutus beni Eigenmann, 1911 Fr native    7.30 cm SL male/unsexed   + 
Characidae Creagrutus britskii Vari & Harold, 2001 Fr native   5.25 cm SL male/unsexed  Found in the upper Tocantins River basin (Ref. 38376). - 
Characidae Creagrutus cochui Géry, 1964 Fr native   11.30 cm TL male/unsexed  Found in the Amazon River (Ref. 38376). - 
Characidae Creagrutus cracentis Vari & Harold, 2001 Fr native   6.00 cm TL male/unsexed  Found in the lower portions of Tapajós River basin (Ref. 38376). - 
Characidae Creagrutus figueiredoi Vari & Harold, 2001 Fr native   6.33 cm SL male/unsexed  Found in the Tocantins River drainage in both upper Tocantins and Araguaia River basins (Ref. 38376). - 
Characidae Creagrutus ignotus Vari & Harold, 2001 Fr native   6.23 cm SL male/unsexed  Found in the upper Tapajós River basin (Ref. 38376). - 
Characidae Creagrutus maxillaris (Myers, 1927) Fr native    7.20 cm SL male/unsexed  Recorded from the upper Rio Negro. - 
Characidae Creagrutus menezesi Vari & Harold, 2001 Fr native   7.52 cm SL male/unsexed  Found in the Tocantins River basin and tentatively the Branco and Negro rivers near mouth of Branco (Ref. 38376). - 
Characidae Creagrutus meridionalis Vari & Harold, 2001 Fr native   11.00 cm SL male/unsexed  Found in the upper Paraguay River basin in Mato Grosso (Ref. 38376). + 
Characidae Creagrutus molinus Vari & Harold, 2001 Fr native   5.58 cm SL male/unsexed  Found in the upper Araguaia River basin (Ref. 38376). - 
Characidae Creagrutus mucipu Vari & Harold, 2001 Fr native   5.61 cm SL male/unsexed  Found in the upper Tocantins River basin (Ref. 38376). - 
Characidae Creagrutus nigrotaeniatus Dagosta & Pastana, 2014 Fr native   4.31 cm SL male/unsexed  Known from the upper rio Juruena, rio Tapajós basin, Mato Grosso State (Ref. 94995). - 
Characidae Creagrutus occidaneus Vari & Harold, 2001 Fr native    6.59 cm SL male/unsexed    - 
Characidae Creagrutus petilus Vari & Harold, 2001 Fr native    4.88 cm SL male/unsexed  Found in the upper Machado River, right bank tributary of Madeira River (Ref. 38376). Also Ref. 97589. - 
Characidae Creagrutus phasma Myers, 1927 Fr native   6.60 cm SL male/unsexed   - 
Characidae Creagrutus runa Vari & Harold, 2001 Fr native   6.27 cm SL male/unsexed  Found in the Negro River (Ref. 38376). - 
Characidae Creagrutus saxatilis Vari & Harold, 2001 Fr native   8.17 cm SL male/unsexed  Found in the upper Tocantins River basin in Goiás and Distrito Federal (Ref. 38376). - 
Characidae Creagrutus seductus Vari & Harold, 2001 Fr native   7.03 cm SL male/unsexed  Found in the upper Araguaia River basin (Ref. 38376). - 
Characidae Creagrutus tuyuka Vari & Lima, 2003 Fr native   6.83 cm SL male/unsexed  Known only from Rio Tiquié, a tributary of the Rio Uaupés, in the Rio Negro basin of northwestern Brazil (Ref. 52414). - 
Characidae Creagrutus varii Ribeiro, Benine & Figueiredo, 2004 Fr native   4.20 cm SL male/unsexed  Known from two localities in the upper Rio Paranaiba basin (Ref. 52412). - 
Characidae Creagrutus vexillapinnus Vari & Harold, 2001 Fr native   5.04 cm SL male/unsexed   - 
Characidae Creagrutus yudja Netto-Ferreira & Moreira, 2018 Fr native   3.00 cm SL male/unsexed  Type locality of Creagrutus yudja Pará, Altamira, Praia do Levi, rio Iriri, Rio Xingu basin (Ref. 122128). + 
Characidae Creagrutus zephyrus Vari & Harold, 2001 Fr native   3.98 cm SL male/unsexed  Found in the Negro River (Ref. 38376). - 
Cichlidae Crenicara latruncularium Kullander & Staeck, 1990 Fr native    8.90 cm SL male/unsexed  Known from the Amazon River basin in the Guaporé drainage (Ref. 36377). + 
Cichlidae Crenicara punctulata (Günther, 1863) Fr native    10.00 cm SL male/unsexed  Occurs in the Amazon Basin and Amapá Grande River in Amapá State (Ref. 36377). + 
Cichlidae Crenicichla acutirostris Günther, 1862 Fr endemic    23.00 cm TL male/unsexed  Known from the Amazon River basin, in the Tapajós and Aripuanã River basins (Ref. 36377). Type locality: Rio Cupai, Amazonas, Brazil, 800 mi. from the sea (Ref. 12965, 12251). + 
Cichlidae Crenicichla adspersa Heckel, 1840 Fr endemic  Guensa branca (Portuguese)   29.00 cm SL male/unsexed  Known from the Amazon River basin, in the Guaporé River basin (Ref. 36377). Type locality: Rio Guaporé, Mato Grosso, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Crenicichla alta Eigenmann, 1912 Fr native  Jacundá (Portuguese)  16.00 cm SL male/unsexed  Known from the Amazon River basin, in the Branco River basin (Ref. 36377). + 
Cichlidae Crenicichla anamiri Ito & Rapp Py-Daniel, 2015 Fr native   4.78 cm SL male/unsexed  Known from the middle rio Xingu and in rio Bacajá, upstream of Volta Grande do Xingu (Ref. 104708). Status of threat: NT (nearly threatened) based on IUCN categories and criteria (Ref. 104708). - 
Cichlidae Crenicichla brasiliensis (Bloch, 1792) Fr endemic  Jacundá (Portuguese)  7.80 cm SL male/unsexed  Found in Ceará, Paraíba, Rio Grande do Norte and Pernambuco (Ref. 36377). Also Ref. 12251. - 
Cichlidae Crenicichla britskii Kullander, 1982 Fr native    14.50 cm SL male/unsexed 7 TL Known from the Paraná River basin, in the Paraná River drainage upstream from Guaira (Ref. 36377). Type locality: Estado de São Paulo, mun. Promissão, R. Tietê system, km 143 on BR-153, above road in small brook (Ref. 33021). Also Ref. 12251. + 
Cichlidae Crenicichla cametana Steindachner, 1911 Fr endemic   18.30 cm SL male/unsexed  Known from the Amazon River basin, in the Tocantins River basin (Ref. 36377). Type locality: Tocantins bei Cametá (Ref. 33021). Also Ref. 12251. - 
Cichlidae Crenicichla celidochilus Casciotta, 1987 Fr native  Joaninha (Portuguese)  26.80 cm TL male/unsexed  Found in the Uruguay River (Ref. 79585). Also Ref. 12251, 36377. + 
Cichlidae Crenicichla chicha Varella, Kullander & Lima, 2012 Fr native   13.77 cm SL male/unsexed  Known from the rio Papagaio and tributaries, itself a tributary of the rio Juruena, a major headwater of the rio Tapajós in the state of Mato Grosso. Collected above and below the Cachoeira do Utiariti, a major (about 90 meters high) waterfall in the rio Papagaio (Ref. 91069). - 
Cichlidae Crenicichla cincta Regan, 1905 Fr native    19.50 cm SL male/unsexed  Known from Manaus, near Belem, Ilha Marajo (Ref. 9088). Found in the Amazon River basin (Ref. 36377). + 
Cichlidae Crenicichla compressiceps Ploeg, 1986 Fr endemic   5.73 cm SL male/unsexed  Known from the Amazon River basin, in the lower Tocantins River basin (Ref. 36377). Type locality: rapids downstream of Jatobal (Ref. 33021). Also Ref. 12251. + 
Cichlidae Crenicichla cyanonotus Cope, 1870 Fr native    14.80 cm SL male/unsexed  Known from the Amazon River basin in western Brazil (Ref. 36377). - 
Cichlidae Crenicichla cyclostoma Ploeg, 1986 Fr endemic  Jacundá (Portuguese)   9.60 cm SL male/unsexed  Known from the Amazon River basin, in the lower Tocantins River basin (Ref. 36377). Type locality: Tucurui, residual pools downstream of stowage, after closing the stowage (Ref. 33021). Maybe threatened by extinction due to its restricted distribution in the rapids of Rio Tocantins, a biotope currently destroyed by hydroelectric power plants (Ref. 85327). Also Ref. 12251. - 
Cichlidae Crenicichla empheres Lucena, 2007 Fr native   14.07 cm SL male/unsexed  Type locality, rio Chapecó, on the road Abelardo Luz-Coronel Firmino Martins, Abelardo Luz, state of Santa Catarina, MCP 40960.(holotype of Crenicichla empheres, 10.44 cm SL, male). Known from Rio Chapecó, upper rio Uruguay drainage (Ref. 75870). - 
Cichlidae Crenicichla gaucho Lucena & Kullander, 1992 Fr native    12.70 cm SL male/unsexed  Found in the Uruguay River drainage, in the tributaries of the middle Uruguay River (Comandaí, Ijuí and Piratinim rivers) (Ref. 36377). Type locality: Brazil, State of Rio Grando do Sul, arroio Passo do Alto, near Mineral, município of São Nicolau (Ref. 26688). - 
Cichlidae Crenicichla geayi Pellegrin, 1903 Fr misidentification   18.40 cm SL male/unsexed  Known from the country (Ref. 4537). Occurrence of this species in this country is not confirmed (Ref. 36377). - 
Cichlidae Crenicichla hadrostigma Lucena, 2007 Fr native   11.35 cm SL male/unsexed  Type locality, rio Chapecó, on the old road Coronel de Freitas-Quilombo, Vila São Miguel, Coronel de Freitas, state of Santa Catarina, MCP 40959 (holotype of Crenicichla hadrostigma, 10.01cm SL, male). Known from Upper rio Uruguay drainage, rio Uruguay and rio Chapecó (Ref. 75870). + 
Cichlidae Crenicichla haroldoi Luengo & Britski, 1974 Fr endemic    9.80 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 36377). + 
Cichlidae Crenicichla heckeli Ploeg, 1989 Fr endemic    5.22 cm SL male/unsexed  Known from the Amazon River basin, in the Trombetas River close to Cachoeira Porteira (Ref. 36377). Type locality: Brasilìen, Staat Pará, Trombetas-System, Cachoeira Porteira (Ref. 33021). Also Ref. 12251. - 
Cichlidae Crenicichla hemera Kullander, 1990 Fr endemic    9.70 cm SL male/unsexed  Known from the Amazon River basin, in the upper Aripuanã River in the Madeira River drainage (Ref. 36377). Type locality: Brazil, State of Mato Grosso, Rio Aripuanã drainage, headwater stream tributary to the Rio Cinta Larga where crossed by the road BR-174, 41 km from Juína (Ref. 26677). - 
Cichlidae Crenicichla hummelincki Ploeg, 1991 Fr endemic    10.80 cm SL male/unsexed  Known from the upper Trombetas River basin of the Amazon River basin (Ref. 36377). - 
Cichlidae Crenicichla igara Lucena & Kullander, 1992 Fr endemic  Joaninha (Portuguese)   31.20 cm TL male/unsexed  Known from the Uruguay River drainage, in tributaries of the upper Uruguay River (Ref. 36377). Type locality: Brazil, State of Santa Catarina, município Campos Novos, rio Canoas at Passo do Canoas, (road SC-458), on the road Tupitinga-Celso Ramos (Ref. 26688). - 
Cichlidae Crenicichla iguapina Kullander & Lucena, 2006 Fr endemic    17.63 cm SL male/unsexed  Found only in the rio Ribeira de Iguaoe drainage in São Paulo (Ref. 57632). Also Ref. 84540. - 
Cichlidae Crenicichla iguassuensis Haseman, 1911 Fr native  Joaninha (Portuguese)   33.00 cm SL male/unsexed 9.64 SL Known from the Paraná River basin, in the Iguaçu River basin (Ref. 36377). Type locality: Porto União da Victoria, Rio Iguassú (Ref. 36377). - 
Cichlidae Crenicichla inpa Ploeg, 1991 Fr endemic    18.40 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36377). Type locality: State of Amazonas, Río Amazonas system, Ilha do Careiro (Ref. 36377). - 
Cichlidae Crenicichla isbrueckeri Ploeg, 1991 Fr endemic    9.50 cm SL male/unsexed  Known from the Amazon River basin, in the Aripuanã River basin (Ref. 36377). Type locality: State of Mato Grosso, Madiera River system, Río Aripuanã, 3 km from Cachoeira de Dardanelos Humboldt (59°27'W, 10°10'S) (Ref. 36377). - 
Cichlidae Crenicichla jaguarensis Haseman, 1911 Fr endemic    14.80 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 36377). + 
Cichlidae Crenicichla jegui Ploeg, 1986 Fr endemic  Jacundá (Portuguese)   20.00 cm SL male/unsexed  Known from the Amazon River basin, in the lower Tocantins River basin (Ref. 36377). Type locality: Itupiranga, Brazil (Ref. 12251). Maybe threatened by extinction due to its restricted distribution in the rapids of Rio Tocantins, a biotope currently destroyed by hydroelectric power plants (Ref. 85327). - 
Cichlidae Crenicichla johanna Heckel, 1840 Fr native  Jacundà (Portuguese), Jacunda (Portuguese), Jacundá (Portuguese), Jacunda piranga (Portuguese), Joana guensa (Portuguese), Johanna guensa (Portuguese), Mariana (Portuguese), Nhacundá (Portuguese), Sabão (Portuguese)   28.30 cm SL male/unsexed  Found in the Amazon River basin and in Amapá State (Ref. 36377). Recorded from Machado river basin (Ref. 97589). + 
Cichlidae Crenicichla jupiaensis Britski & Luengo, 1968 Fr native  Joaninha (Portuguese)   9.30 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 36377). Type locality: Rio Paraná, no Salto de Urubupungá, entre os Estados de Mato Grosso e São Paulo, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Crenicichla jurubi Lucena & Kullander, 1992 Fr endemic  Joaninha (Portuguese)   30.30 cm TL male/unsexed  Known from the Uruguay River (Ref. 79585, 36377). Type locality: Brazil, State of Rio Grande do Sul, rio Marombas at bridge Irìneu Bornhausen. Also Ref. 12251. + 
Cichlidae Crenicichla labrina (Spix & Agassiz, 1831) Fr endemic    16.00 cm SL male/unsexed  Known from the Amazon River basin, in the lower Tocantins River basin (Ref. 36377). + 
Cichlidae Crenicichla lacustris (Castelnau, 1855) Fr native  Jacundá (Portuguese), Joaninha (Portuguese), Maria guensa (Portuguese), Maria guenza (Portuguese), Michola (Portuguese), Mixorne (Portuguese), Nhacundá (Portuguese), Truta brasileira (Portuguese)   35.20 cm TL male/unsexed  Found in coastal drainages of southeastern and eastern Brazil (Ref. 36377). + 
Cichlidae Crenicichla lenticulata Heckel, 1840 Fr endemic  Jacunda (Portuguese), Jacundá (Portuguese), Jacundá açu (Portuguese), Jacundá branco (Portuguese), Jacundá pinima (Portuguese), Jacundá piranga (Portuguese), Jacundá touro (Portuguese), Peixe sabão (Portuguese)   30.00 cm SL male/unsexed  Known from Negro River basin of the Amazon River basin (Ref. 36377). Type locality: Rio-negro, bei Marabitanas, Brazil (Ref. 33021). + 
Cichlidae Crenicichla lepidota Heckel, 1840 Fr native  Guensa-verde (Portuguese), Guenza (Portuguese), Jacundá (Portuguese), Joana mixola (Portuguese), Joana-guensa (Portuguese), Joaninha (Portuguese), João bobo (Portuguese), Nhacundá (Portuguese), Ruballo (Portuguese)   20.90 cm TL male/unsexed  Found in the Paraguay River drainage, middle and lower Uruguay River, Guaporé River drainage in the Amazon River basin, and along the coast of Rio Grande do Sul State (Ref. 36377). Recorded from the Patos lagoon (Ref. 58359). + 
Cichlidae Crenicichla lucenai Mattos, Schindler, Ottoni & Cheffe, 2014 Fr native   14.59 cm SL male/unsexed  Known from the upper Rio das Antas basin, Jacuí river drainage, dos Patos lagoon system, southern Brazil (Ref. 95826). - 
Cichlidae Crenicichla lucius Cope, 1870 Fr native   16.80 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36377). + 
Cichlidae Crenicichla lugubris Heckel, 1840 Fr native  Jacunda (Portuguese), Jacundá (Portuguese), Mariana (Portuguese), Sabão (Portuguese)   32.90 cm TL male/unsexed  Known from the Amazon River basin, in the Branco, Negro and Uatumã rivers (Ref. 36377). Has been found in Manaus, Guapore River, Rio Capim, Rio Negro, etc. (Ref. 12251). + 
Cichlidae Crenicichla macrophthalma Heckel, 1840 Fr native  Jacunda (Portuguese), Jacundá (Portuguese), Nhacundá (Portuguese)   20.00 cm SL male/unsexed  Known from the Amazon River basin, in the Negro, Uatumã, Tapajós, Xingu and Trombetas River basins (Ref. 36377). Type locality: Manaus (Ref. 12965). + 
Cichlidae Crenicichla maculata Kullander & Lucena, 2006 Fr endemic    24.70 cm SL male/unsexed  Known from a limited area north of laguna dos Patos, namely, the lower rio Maquiné, lower rio Três Forquilhas, lagoa dos Quadros, lagoa do Palmital and lagoa Emboaba, State of Rio Grande do Sul; also found in the rio Tubarão drainage, ribeirão São Luis in the rio Itajai-Açu drainage and from rio Itapocu drainage in the State of Santa Catarina (Ref. 57632). Also Ref. 84540. + 
Cichlidae Crenicichla marmorata Pellegrin, 1904 Fr endemic    28.00 cm SL male/unsexed  Found in southern tributaries of the Amazon River from Madeira River to the Tocantins River (Ref. 36377). + 
Cichlidae Crenicichla menezesi Ploeg, 1991 Fr native    18.90 cm TL male/unsexed  Type locality: State of Maranhão, Caieira (Ref. 36377). + 
Cichlidae Crenicichla minuano Lucena & Kullander, 1992 Fr native  Joaninha (Portuguese)   26.00 cm TL male/unsexed  Known from the Uruguay River drainage, in tributaries of the middle an upper Uruguay River (Ref. 36377). Type locality: Brazil, State of Rio Grande do Sul, rio Comandaí, on the road Porto Xavier-Porto Lucena (Ref. 26688). + 
Cichlidae Crenicichla missioneira Lucena & Kullander, 1992 Fr native  Joaninha (Portuguese)   28.30 cm TL male/unsexed  Known from the Uruguay River drainage, in tributaries of the upper and middle Uruguay River basin (Ref. 36377). Type locality: Brazil, State of Rio Grande do Sul, rio Comandaí, on the road Porto Xavier-Porto Lucena (Ref. 26688) - 
Cichlidae Crenicichla monicae Kullander & Varella, 2015 Fr native   27.25 cm SL male/unsexed ;22.43 cm SL female  Known from the lower Rio Uaupés at the village of Taracuá, Trovão and the Uaupés near the mouth, Nossa Senhora da Guia on the Rio Içana, and the tributary Rio Cubaté (Ref. 104137). - 
Cichlidae Crenicichla mucuryna Ihering, 1914 Fr endemic    11.30 cm SL male/unsexed  Known from the Mucuri River basin (Ref. 36377). Type locality: Theophilo Otoni, rìo Todos os Santos, affl. Do Mucury, Est. de Minas Geraes (Ref. 33021). + 
Cichlidae Crenicichla niederleinii (Holmberg, 1891) Fr native  Joaninha (Portuguese)  23.50 cm SL male/unsexed  Known from the Paraná River basin (Ref. 36377). + 
Cichlidae Crenicichla notophthalmus Regan, 1913 Fr native  Jacunda (Portuguese)   7.60 cm SL male/unsexed  Known from the lower Negro River basin of the Amazon River basin (Ref. 36377). Type locality: Amazon R. at Manaus. + 
Cichlidae Crenicichla pellegrini Ploeg, 1991 Fr endemic    15.70 cm SL male/unsexed  Known from the Amazon River basin, in the Aripuanã River basin (Ref. 36377). Type locality: State of Mato Grosso, Madeira River system, Río Aripuanã, Igarapé do Porto (Ref. 36377). - 
Cichlidae Crenicichla percna Kullander, 1991 Fr endemic    22.00 cm SL male/unsexed  Known from the Amazon River basin, in the Xingu River at Cachoeira do Espelho and Altamira (Ref. 36377). Type locality: Brazil, State of Pará, Rio Xingu drainage, Cachoeira do Espelho (Ref. 36377). Also Ref. 12251. + 
Cichlidae Crenicichla phaiospilus Kullander, 1991 Fr endemic    24.00 cm SL male/unsexed  Known from the Amazon River basin, in the Xingu River drainage at Cachoeira von Martius and Goritire (Ref. 36377). Type locality: Brazil, State of Pará, Rio Xingu drainage, município de São Felix do Xingu, Rio Fresco, Aldeia Gorotire (Ref. 26750). Also Ref. 12251. - 
Cichlidae Crenicichla ploegi Varella, Loeb, Lima & Kullander, 2018 Fr endemic   19.00 cm SL male/unsexed ;11.59 cm SL female   - 
Cichlidae Crenicichla prenda Lucena & Kullander, 1992 Fr native    8.70 cm SL male/unsexed  Known from the upper Uruguay river basin (Ref. 36377). Type locality: Brazil, State of Santa Catarina, rio Jacutinga, on the road BR 283 Seara-Concórdia (Ref. 36377). Also Ref. 12251. - 
Cichlidae Crenicichla proteus Cope, 1872 Fr native   15.50 cm SL male/unsexed  Known from the upper Purus basin, Amazon River basin (Ref. 36377). + 
Cichlidae Crenicichla punctata Hensel, 1870 Fr native  Joana mixola (Portuguese)   23.10 cm SL male/unsexed  Known from the Laguna dos Patos and Lagoa Mirim basins in Rio Grande do Sul (Ref. 36377). Type locality: aus dem Guahyba bei Porto Alegre [originally also: Bächen des Urwaldes. Waldbächen von der deutschen Colonie Sta. Cruz in Rio Grande do Sul] (Ref. 36377). + 
Cichlidae Crenicichla pydanielae Ploeg, 1991 Fr endemic    17.80 cm SL male/unsexed  Known from Amazon River basin, in the Trombetas River drainage above Cachoeira Porteira (Ref. 36377). Type locality: State of Pará, Trombetes River system, Igarapé at km 10 of BR 163 at level of bridge (Ref. 36377). - 
Cichlidae Crenicichla regani Ploeg, 1989 Fr native    7.93 cm SL male/unsexed  Known from the Amazon River basin, in the Trombetas River at Cachoeira Porteira (Ref. 36377). Type locality: Left trib. to Cachoeira Porteira, Rio Trombetas system, Pará, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Crenicichla reticulata (Heckel, 1840) Fr, Fi native  Peixe sabão (Portuguese), Jacundá (Portuguese), Nhacundá (Portuguese), Peixe sabao (Portuguese)   29.50 cm SL male/unsexed ;23.00 cm SL female  Known from the Amazon River basin (Ref. 36377). Found in fish markets in Santarém (Ref. 12202). Also Ref. 12251. + 
Cichlidae Crenicichla rosemariae Kullander, 1997 Fr endemic  Rubanana (Portuguese)   24.40 cm SL male/unsexed  Known from the Suiá-Missu River, upper Xingu River drainage, Amazon River basin (Ref. 36377). Type locality: Brazil, State of Pará, Rio Xingu drainage, Córrego do Gato. Recorded from the Rio Suiá-Missu, Rio Xingu drainage (Ref. 26135). - 
Cichlidae Crenicichla santosi Ploeg, 1991 Fr endemic    12.00 cm SL male/unsexed  Known from the Amazon River basin, in the Machado River of Rondônia (Ref. 36377). Type locality: State of Rondônia, Rio Madeira system, Río Machado, Jiparaná: Río Urupa (Ref. 36377). - 
Cichlidae Crenicichla saxatilis (Linnaeus, 1758) Fr misidentification  Jacundà (Portuguese), Guensa verde (Portuguese), Guenza verde (Portuguese), Jacundá (Portuguese), Jacundá coroa (Portuguese), Nhacundá (Portuguese)   20.00 cm SL male/unsexed  Reported to occur in this country (Ref. 4537). Occurrence in the country not confirmed (Ref. 26372, 36377). + 
Cichlidae Crenicichla scottii (Eigenmann, 1907) Fr native  Joaninha (Portuguese)   24.00 cm SL male/unsexed  Known from the Uruguay River drainage (Ref. 36377). + 
Cichlidae Crenicichla semicincta Steindachner, 1892 Fr native    17.10 cm SL male/unsexed  Found in the Acre River basin (Ref. 97592). + 
Cichlidae Crenicichla semifasciata (Heckel, 1840) Fr native  Joana-guensa (Portuguese), Joaninha (Portuguese)   17.66 cm SL male/unsexed  Known from the Paraguay River, Paraná River basin in the (Ref. 36377). - 
Cichlidae Crenicichla stocki Ploeg, 1991 Fr endemic    25.00 cm TL male/unsexed  Known from the Amazon River basin, in the Tocantins River basin. Type locality: State of Pará, Río Tocantins system, Capuaraná (Ref. 36377). - 
Cichlidae Crenicichla strigata Günther, 1862 Fr native  Borboleta pintada (Portuguese), Jacundá (Portuguese), Mariana (Portuguese), Nhacundá (Portuguese), Sabão (Portuguese)   30.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36377). Type locality: River Capin; River Cupai (800 miles from the sea) (Ref. 36377) + 
Cichlidae Crenicichla tendybaguassu Lucena & Kullander, 1992 Fr native  Joaninha (Portuguese)   19.60 cm TL male/unsexed  Known from the Uruguay River drainage, in tributaries of the middle and upper Uruguay River basin (Ref. 36377). Type locality: Brazil, State of Rio Grande do Sul, município Santo Angelo, río Piratinim, Fazenda dos Hinz, Coímbra (Ref. 26688). Also Ref. 12251. + 
Cichlidae Crenicichla ternetzi Norman, 1926 Fr native  Jacunda (Portuguese)  24.50 cm SL male/unsexed   + 
Cichlidae Crenicichla tesay Casciotta & Almirón, 2009 Fr native    11.51 cm SL male/unsexed    - 
Cichlidae Crenicichla tigrina Ploeg, Jégu & Ferreira, 1991 Fr endemic    28.00 cm SL male/unsexed  Known from the Amazon River basin, in the Trombetas River near Cachoeira Porteira (Ref. 36377). Type locality: Brésil, Est. Pará, Rio Trombetas, au niveau de L'embouchure de L'Igarapé Caxipacoré (Ref. 33021). - 
Cichlidae Crenicichla tingui Kullander & Lucena, 2006 Fr endemic    19.50 cm SL male/unsexed  Found in the rio Itapocu drainage and in small coastal rivers draining to the baía de Babitonga (rio Cubatão drainage) and the baía de Paranaguá (rio Jacarei and rio Cachoeira drainages) (Ref. 57632). Also Ref. 84540. - 
Cichlidae Crenicichla urosema Kullander, 1990 Fr endemic    6.88 cm SL male/unsexed  Known from the Amazon River basin, in the Tapajós River at São Luiz (Ref. 36377). Type locality: Brazil, State of Pará, Rio Tapajós, rocky pool at São Luiz upstream of Itaituba (Ref. 36377). Also Ref. 12251. - 
Cichlidae Crenicichla virgatula Ploeg, 1991 Fr endemic    6.62 cm SL male/unsexed  Known from the Amazon River basin in the upper Branco River basin (Ref. 36377). Type locality: State of Roraìma, Río Negro, Río Branco, Río Uraricoera, Ilha de Maracá (Ref. 36377). - 
Cichlidae Crenicichla vittata Heckel, 1840 Fr native  Joaninha (Portuguese), Jacarenguena (Portuguese), Jacundá (Portuguese), Joana guenza (Portuguese), Joana-guensa (Portuguese), Nhacundá (Portuguese)   31.00 cm TL male/unsexed  Known from the lower and middle Rio Uruguai (Ref. 26688). Also found in the Paraguay River, Paraná River basin (Ref. 36377). Also Ref. 36377. + 
Cichlidae Crenicichla wallacii Regan, 1905 Fr native    8.50 cm SL male/unsexed   + 
Crenuchidae Crenuchus spilurus Günther, 1863 Fr native    5.70 cm TL male/unsexed  Known from the Amazon River basin (Ref. 37059). Also Ref. 12225. + 
Loricariidae Cryptancistrus similis Fisch-Muller, Mol & Covain, 2018 Fr native   6.17 cm SL male/unsexed  Found in the upper Parú de Oeste River based on a single specimen (Ref. 116863). - 
Characidae Ctenobrycon alleni (Eigenmann & McAtee, 1907) Fr native  Lambari (Portuguese)   9.00 cm SL male/unsexed  Known from the Paraguay River (Ref. 38376). - 
Characidae Ctenobrycon hauxwellianus (Cope, 1870) Fr native  Lambari (Portuguese), Marupiri (Portuguese), Matapiri (Portuguese), Sardinha (Portuguese) common (usually seen) 8.00 cm SL male/unsexed  Found in the Amazon (Ref. 38376) and Acre River basins (Ref. 97592). Locally abundant (Ref. 598). + 
Characidae Ctenobrycon multiradiatus (Steindachner, 1876) Fr native     - 
Characidae Ctenobrycon spilurus (Valenciennes, 1850) Fr native  Lambari (Portuguese)   8.00 cm SL male/unsexed   + 
Characidae Ctenocheirodon pristis Malabarba & Jerep, 2012 Fr native   3.28 cm SL male/unsexed ;3.36 cm SL female  Found in several locations in Rio Tocantins drainage (Ref. 91049) - 
Gobiidae Ctenogobius shufeldti (Jordan & Eigenmann, 1887) Fr, Br native    8.00 cm TL male/unsexed    + 
Gobiidae Ctenogobius thoropsis (Pezold & Gilbert, 1987) Fr, Br, M native   4.40 cm SL male/unsexed  Museum: USNM 264992 (Ref. 33570). - 
Xenocyprididae Ctenopharyngodon idella (Valenciennes, 1844) Fr introduced  Cara-capim (Portuguese), Carpa capim (Portuguese)   150 cm TL male/unsexed  Reported from the Uruguay River (Ref. 79585). + 
Loricariidae Curculionichthys coxipone Roxo, Silva, Ochoa & Oliveira, 2015 Fr native   2.80 cm SL male/unsexed ;3.00 cm SL female  Found in Rio Cuiaba drainage, Rio Paraguay basin, Mato Grosso State (Ref. 113800). - 
Loricariidae Curculionichthys insperatus (Britski & Garavello, 2003) Fr native   3.02 cm SL male/unsexed  Known from the Upper Rio Paraná drainage in São Paulo and Mato Grosso states (Ref. 53011). Type locality, Rio Capivara, Rio Tietê drainage, Botucatu, São Paulo State (Ref. 53011). + 
Loricariidae Curculionichthys itaim Roxo, Dias, Silva & Oliveira, 2017 Fr native   2.49 cm SL male/unsexed  Known from the following six small streams of the rio Tapajós basin: Igarapé Cipó, Igarapé Nambuaí (type locality), Igarapé Presidente, Igarapé São José, Igarapé Urubutu and rio Tracuá (Ref. 118146). - 
Loricariidae Curculionichthys karipuna Silva, Roxo, Melo & Oliveira, 2016 Fr native   2.39 cm SL male/unsexed  Known from a small stream of the rio Cassiporé, an Atlantic coastal river of northern Amapá and a small stream reaching the rio Jari (Ref. 112322). - 
Loricariidae Curculionichthys luteofrenatus (Britski & Garavello, 2007) Fr native   3.05 cm SL male/unsexed  Known from the upper Rio Tapajós basin in Mato Grosso State (Ref. 75061). - 
Loricariidae Curculionichthys oliveirai (Roxo, Zawadzki & Troy, 2014) Fr native   2.84 cm SL male/unsexed ;3.04 cm SL female  Found in four small to medium-sized streams, the ribeirão Salto Grande, ribeirão Keller, rio Mourão, and the ribeirão Cambira, all tributaries of the rio Ivaí in the upper rio Paraná basin (Ref. 95507). - 
Loricariidae Curculionichthys paresi (Roxo, Zawadzki & Troy, 2014) Fr native   2.62 cm SL male/unsexed  Found in three small tributaries (riacho Águas Claras, riacho Maracaña and riacho São Jorge) that drain to the rio Sepotuba, in the upper rio Paraguay basin (Ref. 95507). - 
Loricariidae Curculionichthys piracanjuba (Martins & Langeani, 2012) Fr native   2.71 cm SL male/unsexed   - 
Loricariidae Curculionichthys sabaji Roxo, Silva, Ochoa & Oliveira, 2015 Fr native   2.36 cm SL male/unsexed  Found in five localities in the Rio Xingu basin: two at Rio 13 de Maio, one at Rio Coronel Vanick, one at Rio Couto de Magalhães and one at Rio Curuá (Ref. 113800). - 
Loricariidae Curculionichthys sagarana Roxo, Silva, Ochoa & Oliveira, 2015 Fr native   2.30 cm SL male/unsexed ;2.44 cm SL female  Found along Rio das Velhas drainage in the following localities: one at Rio 13 de Maio, one at Pardo Grande, and one at Rio Curimataí, all in Rio São Francisco basin, Minas Gerais State (Ref. 113800). - 
Loricariidae Curculionichthys scaius Calegari, Gamarra & Reis, 2018 Fr native  abundant (always seen in some numbers) 2.40 cm SL male/unsexed  Type locality of Curculionichthys scaius, Brazil, Mato Grosso, Aripuanã, creek on road to Lontra, tributary to the Aripuanã River drainage, Madeira River basin (Ref. 119375).

Conservation status: The extinction risk of this species is assessed as low despite limited knowledge of its geographic distribution. It is so far known from a single locality in a creek tributary to the Aripuanã River, Madeira River basin, but additional collecting effort in the region will likely reveal a broader distribution. The species was naturally abundant and specific threats were not detected in the area, which is largely well preserved. Thus, it is tentatively categorized as Least Concern (LC) according to the International Union for Conservation of Nature (IUCN) categories and criteria (Ref. 119375). 

+ 
Loricariidae Curculionichthys tukana Roxo, Dias, Silva & Oliveira, 2017 Fr native   2.40 cm SL male/unsexed  Found in the following five small rivers of the rio Tocantins basin: ribeirão Bofe, córrego Bom Jardim, rio Parauapebas, rio Sossego and a small unnamed tributary of rio Caraíbas (Ref. 118146). - 
Curimatidae Curimata acutirostris Vari & Reis, 1995 Fr endemic    15.90 cm SL male/unsexed ;18.90 cm SL female  Known from the upper Araguaia River basin (Ref. 38013). - 
Curimatidae Curimata aspera Günther, 1868 Fr native   21.20 cm SL male/unsexed  Recorded from the western section of the Amazon basin (Ref. 34109). Also Ref. 38013. - 
Curimatidae Curimata cisandina (Allen, 1942) Fr native   12.20 cm SL male/unsexed  Known from Branco River and middle and upper portions of the Amazon River basin (Ref. 38013). Recoded from the middle and upper Rio Solimoes (Ref. 26629). Also Ref. 34109. - 
Curimatidae Curimata cyprinoides (Linnaeus, 1766) Fr native  Branquinha (Portuguese), Branquiha-baiao (Portuguese), Branquinha baião (Portuguese), Branquinha-baião (Portuguese), Durão (Portuguese), Solta baião (Portuguese)   23.00 cm SL male/unsexed  Known from the lower Amazon and from Rio Tocantins (Ref. 12225). Also Ref. 26629. + 
Curimatidae Curimata incompta Vari, 1984 Fr native    16.70 cm SL male/unsexed   - 
Curimatidae Curimata inornata Vari, 1989 Fr, Fi endemic  Branquinha (Portuguese)   21.00 cm SL male/unsexed  Known from the middle and southern portions of Amazon River basin, Tocantins River (Ref. 38013). Found in fish markets in Santarém (Ref. 12202). Museum: edge of river, Itaituba, Rio Tapajós, Pará, MZUSP 28648 (holotype of C. inornata, 12.7 cm SL) (Ref. 27925). Also Ref. 34109, 38013. + 
Curimatidae Curimata knerii Steindachner, 1876 Fr native    17.70 cm SL male/unsexed  Known from the Amazon River basin (Ref. 26629, 38013). Also Ref. 34109, 38013. - 
Curimatidae Curimata macrops Eigenmann & Eigenmann, 1889 Fr endemic    18.50 cm SL male/unsexed  Known from the Poti and Parnaíba rivers in northeastern Brazil (Ref. 26629, 38013). Also Ref. 34109. + 
Curimatidae Curimata ocellata Eigenmann & Eigenmann, 1889 Fr native    22.50 cm SL male/unsexed  Known from the Amazon and Negro River basins (Ref. 38013). Also Ref. 26629. - 
Curimatidae Curimata roseni Vari, 1989 Fr native    19.50 cm SL male/unsexed  Known from the Amazon River basin (Ref. 26629, 38013). Museum: cataract pool, Cachoeira do Bem Querer, Rio Branco, Roraima, MZUSP 28651 (holotype of C. roseni, 13.18 cm SL) (Ref. 27925). - 
Curimatidae Curimata vittata (Kner, 1858) Fr native    19.60 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38013). Also Ref. 12371. + 
Curimatidae Curimatella alburnus (Müller & Troschel, 1844) Fr native  Saguiru de rabo amarelo (Portuguese)   18.80 cm SL male/unsexed  Known from Pará in Rio Maicá and Lagoa along margin of Rio Tocantins, near Baiao; Roraima in Rio Branco, Maraá; Amazonas in Rio Negro, Paraná de Janauacá, Paraná do Janauari, Lago Janauari near Manaus, Lago Grande de Manacapuru, Rio Solimoes above Manacapuru, Rio Tefé in Mucura,Igarapé Chefe, Lago Beruri, Rio Purus, Lago Castro at the mouth of Rio Purus, Lago Urini at the mouth of Rio Japurá, Lago do Coarí, Rio Jutaí, Rio Javarí along Brazilian-Peruvian border ; Mato Grosso in Rio Guaporé and Rio Branco (Ref. 28798). Also Ref. 38013. - 
Curimatidae Curimatella dorsalis (Eigenmann & Eigenmann, 1889) Fr native  Curimbatazinho (Portuguese)   14.90 cm TL male/unsexed  Known from Rio Negro, Rio Paraguai and lagoons along Rio Tocantins (Ref. 28798). Also Ref. 38013. + 
Curimatidae Curimatella immaculata (Fernández-Yépez, 1948) Fr native  Piaba (Portuguese), Saburu reis (Portuguese)   18.80 cm TL male/unsexed  Known from Rio Tocantins and Rio Madeira. + 
Curimatidae Curimatella lepidura (Eigenmann & Eigenmann, 1889) Fr endemic  Manjuba (Portuguese), Aragu (Portuguese), Saguiru (Portuguese)   11.30 cm SL male/unsexed  Known from Rio São Francisco of eastern Brazil (Ref. 28798, 38013). + 
Curimatidae Curimatella meyeri (Steindachner, 1882) Fr native    18.40 cm SL male/unsexed  Found in Amazonas (Rio Madeira, Rio Purus, Lower Rio Negro, Lago Janauari, Paraná do Mocambo near Parantins, Lago Amaná at the mouth of Rio Japurá, Igarapé Manduaçu, Igarapé Xicanga, Humaita), Rondonia (Rio Madeira, Calama) and Acre (Rio Juruá, Cruzeiro do Sul). - 
Curimatidae Curimatopsis cryptica Vari, 1982 Fr native    6.50 cm TL male/unsexed  Known from the Brazilian Amazon (Ref. 12225). Museum: Igarapé Anapichi leading to Rio Negro, MZUSP 15975 (Ref. 27925). + 
Curimatidae Curimatopsis evelynae Géry, 1964 Fr, Fi native    4.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38013). Also Ref. 4537. + 
Curimatidae Curimatopsis macrolepis (Steindachner, 1876) Fr, Fi native    6.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38013). Found in the streams of the rio Machado Basin, Rondônia State (Ref. 97589). Also Ref. 4537. + 
Curimatidae Curimatopsis microlepis Eigenmann & Eigenmann, 1889 Fr native   8.90 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38013). Type locality: Jatuarana, Amazonas, Brazil (Ref. 26282). - 
Curimatidae Curimatopsis myersi Vari, 1982 Fr native    4.35 cm SL male/unsexed  Known from Paraguay River basin (Ref. 38013). - 
Chacidae Cyanogaster noctivaga Mattox, Britz, Toledo-Piza & Marinho, 2013 Fr native   1.74 cm SL male/unsexed  Type locality of Cyanogaster noctivaga, Amazonas: Santa Isabel do Rio Negro: rock plateau beach along Rio Negro, near mouth of Rio Urubaxi, The type locality is near the mouth of Rio Urubaxi, a right bank tributary of Rio Negro, in the vicinity of Santa Isabel do Rio Negro. It was also collected from the surroundings of Barcelos and from the middle Rio Tiquié (Ref. 93233). - 
Cynodontidae Cynodon gibbus (Agassiz, 1829) Fr, Fi native  Icanga (Portuguese), Cachorrinha (Portuguese), Cacudinha (Portuguese), Cacunda (Portuguese), Minguilista (Portuguese), Peixe-cachorro (Portuguese)   32.20 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38270). Found in fish markets in Santarém (Ref. 12202). Also Ref. 598. + 
Cynodontidae Cynodon septenarius Toledo-Piza, 2000 Fr native   31.20 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38270). - 
Rivulidae Cynolebias akroa Nielsen, Martins, Araujo, Lira & Faour, 2018 Fr native   7.50 cm SL male/unsexed ;6.13 cm SL female  Type locality of Cynolebias akroa, from a temporary pool at road BA-225, rio Preto basin (Rio São Francisco basin), Prazeres, Bahia (Ref. 127992). - 
Rivulidae Cynolebias altus Costa, 2001 Fr endemic   13.33 cm SL male/unsexed ;9.39 cm SL female  Known only from some localities along rio São Francisco floodplains, right bank, Boa Vista do Lagamar and Paratinga, Bahia (Ref. 40938). Also Ref. 36579. - 
Rivulidae Cynolebias attenuatus Costa, 2001 Fr endemic   10.53 cm SL male/unsexed ;7.08 cm SL female  Known from some localities along rio São Francisco floodplains, between Bom Jesus da Lapa and about 33 km to the south, Bahia, NE Brazil (Ref. 40938). Also Ref. 36579. - 
Rivulidae Cynolebias elegans Costa, 2017 Fr native   3.79 cm SL male/unsexed ;3.69 cm SL female  Known only from a temporary pool in the Verde Grande River drainage in Bahia (Ref. 118117). - 
Rivulidae Cynolebias gibbus Costa, 2001 Fr endemic   9.81 cm SL male/unsexed ;8.73 cm SL female  Known from the middle São Francisco River basin (Ref. 36579). Type locality, temporary pool 9.5 km N of Sítio do Mato, Bahia, Brazil (Ref. 40938). - 
Rivulidae Cynolebias gilbertoi Costa, 1998 Fr endemic   5.00 cm SL male/unsexed ;3.60 cm SL female  Bahia: temporary pond about 30 km South of Bom Jesus da Lapa, near rio São Francisco (type locality). All types from the same locality. Holotype: MZUSP 52304 (1 male, 46.2 mm SL); Paratypes: MZUSP (1 female 34.1), UFRJ 4470 (1 male 40.0, 2 females 34.3 & 37.1), UFRL 4471 (2 females 32.9 & 35.9, cleared and stained). Also Ref. 40938, 36579. - 
Rivulidae Cynolebias gorutuba Costa, 2017 Fr native   8.88 cm SL male/unsexed  Known only from pools in the floodplains of the Gorutuba River in Janaúba, Minas Gerais (Ref. 118117). - 
Rivulidae Cynolebias griseus Costa, Lacerda & Brasil, 1990 Fr endemic    8.34 cm SL male/unsexed ;5.52 cm SL female  Known only from its type locality, a temporary pool close to the rio Paranã, upper rio Tocantins basin, Goiás, central Brazil (Ref. 40938). Also Ref. 27139, 36579. + 
Rivulidae Cynolebias itapicuruensis Costa, 2001 Fr endemic  Peixe-sabão (Portuguese)  8.74 cm SL male/unsexed ;6.56 cm SL female  Known only from the temporary pool in Capim Grosso, rio Itapicururú basin, Bahia, Brazil (Ref. 40938). Also Ref. 36579. + 
Rivulidae Cynolebias leptocephalus Costa & Brasil, 1993 Fr endemic   12.53 cm SL male/unsexed ;8.94 cm SL female  Known from the middle São Francisco River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Cynolebias microphthalmus Costa & Brasil, 1995 Fr endemic  Peixe-de-nuvem (Portuguese)  12.00 cm TL male/unsexed ;5.02 cm SL female  Known from NE Brazil, in the Jaguaribe and Mossoró river basins, eastern Ceará and western Rio Grande do Norte states (Ref. 40938). Also Ref. 36579. - 
Rivulidae Cynolebias obscurus Costa, 2014 Fr, Thr native   4.93 cm SL male/unsexed ;3.86 cm SL female  Occurs in vestigial small pools in Paramirim river drainage, São Francisco River basin. Considered a critically endangered species due to the considerable agricultural pressure in the few remaining habitats and the reduced area of occupancy (Ref. 97357). - 
Rivulidae Cynolebias ochraceus Costa, 2014 Fr, Thr native  scarce (very unlikely) 5.73 cm SL male/unsexed ;5.21 cm SL female  Found only in the area of the type locality, close to the road BR-349, about 12 km W from the town of Bom Jesus da Lapa. Another specimen was caught in a pool near the village of Malhada, about 135 km S of the type locality, suggesting a wider geographical distribution in the middle São Franciso basin. This species should be classified as endangered due to its rarity and the highly deforested state of the area of the type locality (Ref. 97357). - 
Rivulidae Cynolebias oticus Costa, 2014 Fr native   8.23 cm SL male/unsexed ;7.07 cm SL female  Found only in the Verde river drainage, near the village of Pindaí, São Francisco River basin. The current reduced area of occupancy suggests that this species could be considered vulnerable (Ref. 97357). - 
Rivulidae Cynolebias paraguassuensis Costa, Suzart & Nielsen, 2007 Fr native    Known from the Paraguaçu River basin in northeastern Brazil (Ref. 58745). - 
Rivulidae Cynolebias parietalis Costa, 2014 Fr native   7.65 cm SL male/unsexed ;6.39 cm SL female  Found in temporary pools in the floodplains of both banks of the Verde Grande river, close to the village of Gado Bravo, São Francisco River basin (Ref. 97357) - 
Rivulidae Cynolebias parnaibensis Costa, Ramos, Alexandre & Ramos, 2010 Fr native   5.45 cm SL male/unsexed  Type locality, Estado do Piauí, Município de Jacobina do Piauí, seasonal lagoon at the right side of the road between Conceição do Canindé and Jacobina do Piauí. UFPB 6719 (holotype of Cynolebias parnaibensis, 5.45 cm SL, male) (Ref. 84460). + 
Rivulidae Cynolebias perforatus Costa & Brasil, 1991 Fr endemic   12.00 cm TL male/unsexed ;9.04 cm SL female  Known from the middle São Francisco River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Cynolebias porosus Steindachner, 1876 Fr endemic  Peixe de nuvem (Portuguese)  15.00 cm TL male/unsexed  Found in the Atlantic coastal plains (Ref. 36579). Known only from the São Francisco river floodplain between the city of Petrolina and village of Ibaré. Considered criticically endangered due to the sharp reduction of habitats (Ref. 97357). Also Ref. 27139, 40938. + 
Rivulidae Cynolebias rectiventer Costa, 2014 Fr native  abundant (always seen in some numbers) 10.18 cm SL male/unsexed ;8.12 cm SL female  Found only in two adjacent temporart lagoons situated in the floodplain of a seasonal tributary to the Verde river, about 3 km distant from that tributary and about 18 km W from the Verde river, which is a right-bank tributary of the lower-middle São Francisco River Basin in the Bahia state (Ref. 97357). - 
Rivulidae Cynolebias roseus Costa, 2014 Fr native   4.66 cm SL male/unsexed ;5.23 cm SL female  Recorded from a single locality near the town of Barra, in the left-bank floodplain of the São Francisco River. Found in a remnant temporary pool, in an area occupied by cattle farms and plantations (Ref. 97357). - 
Rivulidae Cynolebias vazabarrisensis Costa, 2001 Fr endemic  Peixe-sabão (Portuguese)  7.64 cm SL male/unsexed ;5.95 cm SL female  Known only from the type locality , 33 km S of Bendegó, Bahia, rio Vazabarris basin, NE Brazil. - 
Rivulidae Cynopoecilus fulgens Costa, 2002 Fr native   3.89 cm SL male/unsexed ;2.93 cm SL female  Found in the coastal plains adjacent to the outer edge of the lagoa dos Patos, southern Brazil. Type locality, temporary pool, road BR-101, 5 km N São José do Norte, Rio Grande do Sul (Ref. 42931). - 
Rivulidae Cynopoecilus intimus Costa, 2002 Fr native   2.66 cm SL male/unsexed ;2.16 cm SL female  Known from upper rio Jacuí, río Vacacaí drainage, southern Brazil. Type locality, temporary swamp close to a stream tributary to rio Vacacaí, rio Jacuí basin, road BR-392, 6 km NW of Vila Block, Rio Grande do Sul (Ref. 42931). - 
Rivulidae Cynopoecilus melanotaenia (Regan, 1912) Fr native  Gaúcho (Portuguese)  4.34 cm SL male/unsexed ;3.53 cm SL female  Known from the stream floodplains along inner edge of lagoa dos Patos and coastal floodplains on the outer edge of lagoa Mirim, southern Brazil and eastern Uruguay (Ref. 42931). Also Ref. 27139. + 
Rivulidae Cynopoecilus multipapillatus Costa, 2002 Fr native    3.80 cm SL male/unsexed ;2.70 cm SL female  Found in the coastal plains of northern Rio Grande do Sul state and southern Santa Catarina state, southern Brazil. Type locality, temporary pool between road RS-787 and lagoa da Fortaleza, Rio Grande do Sul (Ref. 42931). - 
Rivulidae Cynopoecilus nigrovittatus Costa, 2002 Fr native   4.43 cm SL male/unsexed ;3.20 cm SL female  Known from the lower Jacuí basin, southern Brazil. Type locality, rio Caí floodplains, Montenegro, Rio Grande do Sul (Ref. 42931). Also Ref. 98301. - 
Rivulidae Cynopoecilus notabilis Ferrer, Wingert & Malabarba, 2014 Fr native   4.05 cm SL male/unsexed ;3.15 cm SL female  Found only in the type locality, a temporary pool in upper portion of rio Gravataí basin, laguna dos Patos system (Ref. 98301). - 
Characidae Cynopotamus amazonum (Günther, 1868) Fr native  Cacunda (Portuguese), Crica (Portuguese)   18.00 cm SL male/unsexed ;23.10 cm female  Known from the Amazon River basin (Ref. 36811). - 
Characidae Cynopotamus argenteus (Valenciennes, 1836) Fr native  Saicanga (Portuguese)  29.50 cm SL male/unsexed   + 
Characidae Cynopotamus essequibensis Eigenmann, 1912 Fr native  Cacunda (Portuguese)  16.00 cm SL male/unsexed   - 
Characidae Cynopotamus gouldingi Menezes, 1987 Fr native    16.50 cm SL male/unsexed  Known from the Madeira River basin (Ref. 36811). Museum: Rio Madeira at Calama, Territory of Rondônia, MZUSP 35474 (holotype, 15.2 cm SL) (Ref. 27925). - 
Characidae Cynopotamus juruenae Menezes, 1987 Fr native   8.50 cm SL male/unsexed  Known from the Juruena River basin (Ref. 36811). Museum: upper Rio Juruena, Mato Grosso, MZUSP 35475 (holotype, 8.5 cm SL) (Ref. 27925). - 
Characidae Cynopotamus kincaidi (Schultz, 1950) Fr native  Saicanga (Portuguese), Peixe-cachorro (Portuguese)   31.50 cm TL male/unsexed  Known from the Paraguay River basin (Ref. 36811) and Uruguay River (Ref. 79585). - 
Characidae Cynopotamus tocantinensis Menezes, 1987 Fr native  Cacunda (Portuguese)  21.00 cm SL male/unsexed  Known from the Tocantins River basin (Ref. 36811). Museum: Igarapé Pojuca, Rio Itacaiunas, Serra dos Carajás, Pará, MZUSP (holotype, 15.4 cm SL) (Ref. 27925). + 
Characidae Cynopotamus xinguano Menezes, 2007 Fr native   15.20 cm TL male/unsexed  Known from the middle-upper tributaries of rio Xingu basin (Ref. 72392). - 
Sciaenidae Cynoscion acoupa (Lacepède, 1801) Fr, Br, M, Fi native  Tacupapirerna (Portuguese), Calafetão (Portuguese), Cambucu (Portuguese), Cambuçu (Portuguese), Cambugu (Portuguese), Cambussu (Portuguese), Cupá (Portuguese), Guatupucá (Portuguese), Pescada (Portuguese), Pescada Amarela (Portuguese), Pescada vermelha (Portuguese), Pescada-amarela (Portuguese), Pescada-cascuda (Portuguese), Pescada-de-escama (Portuguese), Pescada-dourada (Portuguese), Pescada-selvagem (Portuguese), Pescada-ticupá (Portuguese), Pescada-verdadeira (Portuguese), Pescadinha-de-alto-mar (Portuguese), Tacupapirema (Portuguese), Ticoá (Portuguese), Ticupá (Portuguese), Tipuca (Portuguese), Tucupapirema (Portuguese)  110 cm TL male/unsexed 39.9 TL Caught by shrimp trawl in Pirambu, Sergipe (Ref. 118626). + 
Sciaenidae Cynoscion steindachneri (Jordan, 1889) Fr, Br, M native  Pescada-verdadeira (Portuguese), Juruapara (Portuguese), Pescada (Portuguese), Pescada-branca (Portuguese), Pescada-comum (Portuguese), Pescada-jaguara (Portuguese)  110 cm TL male/unsexed  C: Refs. 5217, 65987, 94486; M: Ref. 65987; O: Ref. 65987. + 
Curimatidae Cyphocharax abramoides (Kner, 1858) Fr, Fi native  Branquinha (Portuguese), Piratipióca (Portuguese)  21.30 cm SL male/unsexed  Museum: mouth of Rio Negro, Amazon, NMW 67402 (holotype of C. abramoides, 13.3 cm SL) (Ref. 11334). Found in fish markets in Santarém (Ref. 12202). + 
Curimatidae Cyphocharax aninha Wosiacki & Miranda, 2014 Fr native   3.85 cm SL male/unsexed  Known only from the Rio Mopeco, a left bank tributary of the Rio Paru, left of the lower Rio Amazonas in Pará State (Ref. 94769). - 
Curimatidae Cyphocharax boiadeiro Melo, 2017 Fr native   6.07 cm SL male/unsexed  Found only in the headwaters of the rio Araguaia, Amazon basin in the municipality of Alto Araguaia, Goiás/Mato Grosso state boundary in central Brazil (Ref. 117339). - 
Curimatidae Cyphocharax corumbae (Pavanelli & Britski, 1999) Fr native  Saguiru (Portuguese)  11.70 cm SL male/unsexed  Type locality of Steindachnerina corumbae, Goiás State, Caldas Novas, Rio Pirapitinga, tributary of Rio Corumbá. Known from Rio Corumbá, Rio Paranaíba system, upstream of Itumbiara dam, upper Rio Paraná basin (Ref. 39251) - 
Curimatidae Cyphocharax festivus Vari, 1992 Fr native   16.70 cm TL male/unsexed  Known from Pará and Amazonas (Ref. 11334). Also Ref. 38013. + 
Curimatidae Cyphocharax gangamon Vari, 1992 Fr native   4.70 cm SL male/unsexed  Known from Tapajós River basin (Ref. 38013). Museum: Pará, Rio Tapajos, Monte Cristo, Lago da Santa Clara, MZUSP 022037 (holotype of C. gangamon); MZUSP 41752, USNM 309290 (paratypes). Mato Grosso, Rio Arinos, Porto dos Gauchos, USNM 267991, MZUSP 41754 (Ref. 11334). Also Ref. 27925. + 
Curimatidae Cyphocharax gilbert (Quoy & Gaimard, 1824) Fr native  Curimabatá (Portuguese), Papaterra (Portuguese), Saguiru (Portuguese)   24.20 cm TL male/unsexed  Specimens were collected from the rivers of Rio de Janeiro, Sao Paulo, Minas Gerais, Espirito Santo, and Bahia (Ref. 11334). Museum: Rio Doce, Espirito Santo, MZUSP 1958 (paratype of P. grandocule, 12.3 cm SL) (Ref. 27925). + 
Curimatidae Cyphocharax gillii (Eigenmann & Kennedy, 1903) Fr native  Curimbatazinho (Portuguese)   10.00 cm SL male/unsexed  Found in the rivers of Mato Grosso and Mato Grosso do Sul (Ref. 11334). Also Ref. 38013. + 
Curimatidae Cyphocharax gouldingi Vari, 1992 Fr native    15.80 cm TL male/unsexed  Known from the rivers of Amapá, and Capim, Tocantins, and lower Xingu River basins in Pará (Ref. 11334). Museum: Amapá, Rio Cupixi, along the road to Serra Navio, from the mouth of a rainforest stream, MZUSP 41762 (holotype, 8.67 cm SL); USNM 268010 and MZUSP 41763 (paratypes) (Ref. 11334). Also Ref. 27925, 38016. + 
Curimatidae Cyphocharax helleri (Steindachner, 1910) Fr native  Branquinha (Portuguese)  10.00 cm SL male/unsexed  Occurs in Cupixi River in Amapa (Ref. 38013). Museum: Rio Cupixi, road to Serra do Navio, USNM 267965 (Ref. 11334). Also Ref. 12225. + 
Curimatidae Cyphocharax leucostictus (Eigenmann & Eigenmann, 1889) Fr native    15.80 cm TL male/unsexed  Known from Amapá, Amazonas, , Roraima, Mato Grosso, and Rondônia (Ref. 11334). Also Ref. 38013. + 
Curimatidae Cyphocharax mestomyllon Vari, 1992 Fr native   4.20 cm SL male/unsexed  Known only from Cachoeira de Bicho-Açu along the Marauiá River, Rio Negro basin. Museum: Cachoeira de Bicho-Açu along the Rio Marauiá, Rio Negro Basin, Amazonas, MZUSP 41755 (holotype, 3.49 cm SL); MZUSP 41756 and USNM 309289 (paratypes) (Ref. 11334). Also Ref. 27925, 38013. + 
Curimatidae Cyphocharax modestus (Fernández-Yépez, 1948) Fr, Fi native  Saguiru (Portuguese), Saguirú (Portuguese) scarce (very unlikely) 16.20 cm SL male/unsexed 7.3 TL Known from the fresh waters of Sao Paulo, Distrito Federal, and Paraná. Found in Piracicaba river (Ref. 50076). Museum: Sao Paulo, Rio Batalha, tributary of Rio Tietê, near Bauru, CAS 20299 (holotype of Curimatorbis modestus, 8.65 cm SL); MZUSP 1350, 5250-1 (paratype) (Ref. 11334). Also Ref. 27925, 31923. + 
Curimatidae Cyphocharax multilineatus (Myers, 1927) Fr native   10.90 cm SL male/unsexed  Known from the upper Negro River (Ref. 38013). Museum: Amazonas: Rio Negro below Daraa, USNM 274102, 274103. Rio Negro at Bucuri, CAS 58605 (holotype of C. multilineatus, formerly IU 17672); CAS-SU 58986. Rio Paduari, MZUSP 21161 (Ref. 11334). Also Ref. 1672. + 
Curimatidae Cyphocharax muyrakytan Bortolo, Lima & Melo, 2018 Fr native   5.43 cm SL male/unsexed  Type locality of Cyphocharax muyrakytan: Rio Arapiuns, Santarem, Para (Ref. 119424). - 
Curimatidae Cyphocharax naegelii (Steindachner, 1881) Fr native  Saguiru (Portuguese)   19.00 cm TL male/unsexed ;19.00 cm TL female 7 TL Known from the upper Paraná River basin (Ref. 38013). Museum: vicinity of Rio Janeiro, NMW 68.808 (holotype of C. nagelii, 11 cm SL) (Ref. 11334). + 
Curimatidae Cyphocharax nigripinnis Vari, 1992 Fr native   6.50 cm SL male/unsexed  Found in central and eastern portions of the Amazon River basin (Ref. 38013). Known from Pará, Roraima, and Amazonas. Museum: Praia do Xeruini, Rio Branco, Roraima, MZUSP 42025 (holotype, 5.16 cm SL); MZUSP 42026, USNM 311109 (paratypes) (Ref. 11334). Also Ref. 27925. + 
Curimatidae Cyphocharax notatus (Steindachner, 1908) Fr native    14.70 cm SL male/unsexed  Known from Pará, Amazonas, and Mato Grosso (Ref. 11334). Found in Tocantins and Capim River basins (Ref. 38013). + 
Curimatidae Cyphocharax pinnilepis Vari, Zanata & Camelier, 2010 Fr native   10.12 cm SL male/unsexed  Found in the Rio Gongogi and Rio Gavião, tributaries of Rio de Contas, a relatively small coastal drainage in Bahia, northeastern Brazil. Possibly endemic to the Rio de Contas drainage as extensive ichthyological collecting efforts through all of the main coastal rivers across Bahia in recent years failed to yield samples of this species from outside the Rio de Contas drainage. Occurs in small rivers with relatively slow currents and somewhat turbid water and also in shallow areas of a reservoir along the Rio Gongogi. These areas have muddy substrates to some degree, with mud particularly prevalent along the Rio do Banco where large amounts of decomposing vegetation covered the river bottom (Ref. 85320). - 
Curimatidae Cyphocharax platanus (Günther, 1880) Fr native  Birú (Portuguese), Curimbatazinho (Portuguese)   13.40 cm SL male/unsexed  Museum: Rio Grande do Sul, Rio Ibicui, between Sao Rafael and Cacequi, MCP 9370. Rio Ibicui, near mouth, municipio de Itaqui, USNM 295976; MZUSP 39784. Rio Uruguai, Itaqui, USNM 295979; MZUSP 1735, 1431. Rio Uruguai, USNM 295977. Itaqui, MZUSP 1735 (Ref. 11334). + 
Curimatidae Cyphocharax plumbeus (Eigenmann & Eigenmann, 1889) Fr native  Sabaru (Portuguese), Pira miri (Portuguese)   17.80 cm SL male/unsexed  Known from the rivers of Pará, Amazonas, Roraima, Rondonia, and Mato Grosso (Ref. 11334). Found in the Amazon and Tocantin River basins (Ref. 38013), rio Machado Basin, Rondônia State (Ref. 97589). + 
Curimatidae Cyphocharax saladensis (Meinken, 1933) Fr, Fi native  Birú (Portuguese), Biru (Portuguese)   9.80 cm TL male/unsexed  Museum: Rio Grande do Sul: Rio Sanga Funda, Rodovia BR 101, Osorio, MCP 8532. Km 16 on BR 116, between Porto Alegre and Pelotas, USNM 220578. Along road between Porto Alegre and Pelotas, USNM 296374. Along highway BR 116, between Porto Alegre and Pelotas, MZUSP 21670. Arroio Don Marcos, along BR 290, MCP 8414 (Ref. 11334). Also Ref. 4537. + 
Curimatidae Cyphocharax sanctigabrielis Melo & Vari, 2014 Fr native   6.70 cm SL male/unsexed  Known from the upper rio Negro, Amazon basin (Ref. 96871). - 
Curimatidae Cyphocharax santacatarinae (Fernández-Yépez, 1948) Fr native  Saguairú (Portuguese), Peixe-Duro (Portuguese), Roncador (Portuguese), Saguaru (Portuguese)   20.10 cm SL male/unsexed  Known from the coastal rivers of the states of Paraná, Santa Catarina, and southern Sao Paulo (Ref. 11334). Museum: Santa Catarina, MZUSP 1806 (Ref. 27925). Also Ref. 38013. + 
Curimatidae Cyphocharax signatus Vari, 1992 Fr native   3.30 cm SL male/unsexed  Museum: Goiás, Rio Vermelho (a tributary of the Rio Araguaia of the Rio Tocantins system), MZUSP 41757 (holotype, 3.34 cm SL); MZUSP 41758 and USNM 308392 (paratypes) (Ref. 11334). Also Ref. 27925. + 
Curimatidae Cyphocharax spilotus (Vari, 1987) Fr native  Biru (Portuguese)  10.40 cm TL male/unsexed  Museum: Rio Grande do Sul, Rio Santa Maria, between Dom Pedrito and Livramento, MZUSP 37133 (holotype of C. spilota, 5.63 cm SL) (Ref. 11334). Also Ref. 27925. + 
Curimatidae Cyphocharax spiluropsis (Eigenmann & Eigenmann, 1889) Fr native    9.00 cm SL male/unsexed  Known from the fresh water of Amazonas, Mato Grosso, and Rondonia states (Ref. 11334). Found in rio Machado basin (Ref. 97589). + 
Curimatidae Cyphocharax spilurus (Günther, 1864) Fr native  Branquinha (Portuguese), Curimbatazinho (Portuguese)  10.40 cm SL male/unsexed  Known from the fresh water of Roraima and Amazonas (Ref. 11334). Occurs in the upper Branco River (Ref. 38013). + 
Curimatidae Cyphocharax stilbolepis Vari, 1992 Fr native   17.00 cm TL male/unsexed  Museum: Rio Xingu, Belo Monte, MZUSP 41759 (holotype, 1045 cm SL); MZUSP 41760 (paratype). Rio Tocantins, USNM 267985; MZUSP 21283. Rio Araguaia, MZUSP 4849 (Ref. 11334). Also Ref. 27925. + 
Curimatidae Cyphocharax vanderi (Britski, 1980) Fr native   6.80 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 38013). Specimens collected from Sao Paulo, Corumbatai (Ref. 11334). Museum: Corumbataí, Sao Paolo, MZUSP 4325 (holotype of C. vanderi, 4.5 cm SL) (Ref. 27925). + 
Curimatidae Cyphocharax vexillapinnus Vari, 1992 Fr native   6.30 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38013). Museum: Amazonas, Lago Terra Preta, januari, USNM 229173 - 229174. Rio Solimoes: Ilha Marchantaria, INPA uncat. Lake near Manaus, USNM 296232; Lago Marchantaria, USNM 268045, 313443. Mouth of Rio Negro, NMW 68815 (Ref. 11334). + 
Curimatidae Cyphocharax voga (Hensel, 1870) Fr native  Biru (Portuguese)  26.30 cm TL male/unsexed  Known from Santa Catarina and Rio Grande do Sul (Ref. 11334). Also recorded from the Patos lagoon (Ref. 58359). + 
Cyprinidae Cyprinus carpio Linnaeus, 1758 Fr, Fi introduced  Carpa (Portuguese), Carpa de escama (Portuguese), Carpa-comum (Portuguese) scarce (very unlikely) 120 cm TL male/unsexed  Recorded in the Piracicaba river (Ref. 50076) and the Uruguay River (Ref. 79585). Also Ref. 1739. + 
Loricariidae Dekeyseria amazonica Rapp Py-Daniel, 1985 Fr native    17.80 cm SL male/unsexed  Found mainly in Solimões River basin and also in the middle and lower Amazon River basin (Ref. 36713). Also Ref. 27116. + 
Loricariidae Dekeyseria brachyura (Kner, 1854) Fr endemic   16.00 cm TL male/unsexed  Known from the lower Negro River basin (Ref. 36713). Also Ref. 6868. + 
Loricariidae Dekeyseria picta (Kner, 1854) Fr endemic   14.00 cm TL male/unsexed  Known from the lower Negro River basin (Ref. 36713). - 
Loricariidae Dekeyseria pulchra (Steindachner, 1915) Fr native  Brazil-butterfly (English)  10.00 cm SL male/unsexed  Known from Negro River (Ref. 36713). Also Ref. 6868. + 
Loricariidae Dekeyseria scaphirhyncha (Kner, 1854) Fr endemic   21.00 cm SL male/unsexed  Known from Negro River basin (Ref. 36713). + 
Loricariidae Delturus angulicauda (Steindachner, 1877) Fr native   18.70 cm SL male/unsexed  Type locality: Rio Mucuri at Santa Clara; Rio Parahyba, se. Brazil (Ref. 26282, 6868). - 
Loricariidae Delturus brevis Reis & Pereira, 2006 Fr native   18.60 cm SL male/unsexed  Type locality, io Araçuaí upstream of its mouth on Rio Jequitinhonha, Araçuaí, Minas Gerais, Brazil, 4-12 Sept. 1989, MZUSP 69858 (holotype of Delturus brevis, 15.21 cm SL, male). Known from Rio Jequitinhonha basin in eastern Brazil (Ref. 57859). - 
Loricariidae Delturus carinotus (La Monte, 1933) Fr endemic    23.50 cm SL male/unsexed  Type locality: Rio Doce, Espirito Santo, e. Brazil (Ref. 26282, 6868). - 
Loricariidae Delturus parahybae Eigenmann & Eigenmann, 1889 Fr native  Cascudo laje (Portuguese)   21.00 cm SL male/unsexed  Type locality: Parahyba, Brazil (Ref. 26282, 6868). - 
Cetopsidae Denticetopsis epa Vari, Ferraris & de Pinna, 2005 Fr native   4.70 cm SL male/unsexed  Known from Rio Tocantins (Ref. 56045). - 
Cetopsidae Denticetopsis seducta Vari, Ferraris & de Pinna, 2005 Fr native    5.10 cm SL male/unsexed  Found in Machado River basin (Ref. 97589). + 
Characidae Deuterodon aphos (Zanata & Akama, 2004) Fr native   5.61 cm SL male/unsexed  Known from the rio Lençois, a tributary of rio Paraguaçu, which is a relatively small, eastern drainage in Bahia State (Ref. 54751). - 
Characidae Deuterodon burgerai (Zanata & Camelier, 2009) Fr native   5.44 cm SL male/unsexed  Found only in córrego Água Boa, a streamlet on the road between Floresta Azul and Almadina, tributary of riacho Pancadinha, itself a tributary of rio Almada, a coastal drainage on southern Bahia (Ref. 81202). + 
Characidae Deuterodon giton (Eigenmann, 1908) Fr native  Piaba do Rio Paraíba (Portuguese)   11.30 cm TL male/unsexed  Found in Paraíba do Sur River basin and coastal streams of Espírito Santo and Rio de Janeiro (Ref. 38376). - 
Characidae Deuterodon hamatilis (Camelier & Zanata, 2014) Fr native   4.37 cm SL male/unsexed  Known from the Rio Paraguaçu basin in Chapada Diamantina, Bahia State (Ref. 95041). - 
Characidae Deuterodon hastatus (Myers, 1928) Fr native     - 
Characidae Deuterodon heterostomus (Eigenmann, 1911) Fr native  Lambari (Portuguese), Mimic scale-eating tetra (English), Lambari-prata (Portuguese)   8.10 cm SL male/unsexed ;10.40 cm SL female  Type locality: Campos on Rio Parahyba, Brazil (Ref. 26282). Found in the coastal rivers of SE Brazil, from Espírito Santo to São Paulo. Caught by casting net, bow-net and hook (Ref. 40388). Also Ref. 598. + 
Characidae Deuterodon iguape Eigenmann, 1907 Fr native  Lambari (Portuguese)  9.84 cm SL male/unsexed  Known from São Paulo (Ref. 598). Found in the Ribeira de Iguape River Basin (Ref. 38376). - 
Characidae Deuterodon intermedius (Eigenmann, 1908) Fr native    7.27 cm SL male/unsexed    + 
Characidae Deuterodon janeiroensis (Eigenmann, 1908) Fr native  Lambari do rio (Portuguese)   11.40 cm SL male/unsexed ;10.60 cm SL female  Recorded from Betari River (Apiaí - SP) - Ribiera do Iguape, Costal Rivers (Ref. 85192). + 
Characidae Deuterodon langei Travassos, 1957 Fr native  Lambari (Portuguese)  12.60 cm TL male/unsexed 6.4 TL Recorded from coastal basins between Cubatão (northern) River, Santa Catarina and the Nhundiaquara River basin, Paraná (Ref. 38376). Museum: Rio Garuvá, Paraná, Garuvá, Santa Catarina, MZUSP 43765 (Ref. 27925). Also Ref. 598. + 
Characidae Deuterodon longirostris (Steindachner, 1907) Fr native   9.13 cm SL male/unsexed  Known from Cubatao (southern) river in Santa Catarina (Ref. 38376). - 
Characidae Deuterodon luetkenii (Boulenger, 1887) Fr native  Lambari (Portuguese)  9.60 cm TL male/unsexed  Found in coastal river drainages and Uruguay River basin in Rio Grande do Sul; Paraíba do Sul River in Rio de Janeiro (Ref. 38376). Also recorded from the Paraguay basin (Ref. 38376) and the Patos lagoon (Ref. 58359). Also Ref. 598. + 
Characidae Deuterodon oyakawai (Santos & Castro, 2014) Fr native   6.43 cm SL male/unsexed  Known from the rio Ribeira de Iguape basin (Ref. 96884). - 
Characidae Deuterodon parahybae Eigenmann, 1908 Fr native   3.90 cm SL male/unsexed  Known from the Itapemirim River basin (Ref. 48602). - 
Characidae Deuterodon pelecus (Bertaco & Lucena, 2006) Fr native   6.00 cm SL male/unsexed  Type locality, Bahia, Cândido Sales, rio Pardo on road BR116, MCP 37570 (holotype of Astyanax pelecus, 5.64 cm SL). Found in the upper rio Pardo drainage, at Cândido Sales, a coastal drainage in the state of Bahia, eastern Brazil (Ref. 57404). - 
Characidae Deuterodon ribeirae (Eigenmann, 1911) Fr native   8.00 cm TL male/unsexed   + 
Characidae Deuterodon rosae (Steindachner, 1908) Fr native  Lambari (Portuguese)  11.66 cm SL male/unsexed  Recorded from Sta. Catharina and Rio Grande do Sul. - 
Characidae Deuterodon sazimai (Santos & Castro, 2014) Fr native   5.67 cm SL male/unsexed  Known from the rio Itapemirim basin in Espírito Santo and rio Doce basin in Minas Gerais (Ref. 96884). - 
Characidae Deuterodon singularis Lucena & Lucena, 1992 Fr native  Lambari (Portuguese)  8.81 cm SL male/unsexed  Museum: Rio Sanga de Areia, Gravatal, Santa Catarina, MZUSP 43766 (Ref. 27925). + 
Characidae Deuterodon stigmaturus (Gomes, 1947) Fr native  Lambari (Portuguese)  10.70 cm SL male/unsexed  Known from Maquiné, Três Forquilhas and Mampituba Rivers basins in Rio Grande do Sul (Ref. 38376). + 
Characidae Deuterodon supparis Lucena & Lucena, 1992 Fr native  Lambari (Portuguese)  10.24 cm SL male/unsexed  Museum: tributary to Rio Itajaí-Açu, near Ibirama, Santa Catarina, MZUSP 43767 (Ref. 27925). - 
Characidae Deuterodon taeniatus (Jenyns, 1842) Fr native  Piaba-branca (Portuguese)   9.60 cm SL male/unsexed  Known from Macaé, São João, and Paraíba do Sul river basins in Rio de Janeiro State, and Benevente river basin in Espírito Santo State (Ref. 119398). Also Ref. 598. - 
Callichthyidae Dianema longibarbis Cope, 1872 Fr native    9.80 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). + 
Callichthyidae Dianema urostriatum (Miranda Ribeiro, 1912) Fr, Or native  Dianema (Portuguese), Rondon (Portuguese)   8.40 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37395). Exported to North America as an aquarium fish (Ref. 4537). + 
Characidae Diapoma alburnum (Hensel, 1870) Fr native    7.40 cm TL male/unsexed  Type locality of Diapoma alburnus Rio Cadea, Rio Grande do Sul (Ref. 26282). Recorded from the Patos lagoon (Ref. 58359); Porto Alegre, Praia das Pombas (Ref. 119400). + 
Characidae Diapoma alegretense (Malabarba & Weitzman, 2003) Fr native   4.20 cm SL male/unsexed  Type locality, Creek on road Santana do Livramento-Alegrete, Alegrete, Rio Grande do Sul (Ref. 50838). - 
Characidae Diapoma dicropotamicus (Malabarba & Weitzman, 2003) Fr native   4.32 cm SL male/unsexed  Type locality of Cyanocharax dicropotamicus Rio Forqueta, Marquês de Souza, Lageado, Rio Grande do Sul (Ref. 50838). Known from rio Jacui drainage (Ref. 55830). Also Ref. 119400. - 
Characidae Diapoma itaimbe (Malabarba & Weitzman, 2003) Fr native   4.46 cm SL male/unsexed  Type locality, Arroio Facão at Mãe dos Homens, trib. of Rio Canoas-rio Mampituba, Praia Grande, Santa Catarina (Ref. 50838). + 
Characidae Diapoma lepiclastum (Malabarba, Weitzman & Casciotta, 2003) Fr native   4.39 cm SL male/unsexed  Type locality, Frio Dourados, Linha Várzea, on road between Severiano de Almeida and Aratiba, Severiano de Almeida, Rio Grande do Sul (Ref. 50838). - 
Characidae Diapoma pyrrhopteryx Menezes & Weitzman, 2011 Fr native   5.60 cm SL male/unsexed  Known from the Rio Canoas basin or tributaries flowing into this basin that belongs to the rio Uruguay basin in Rio Grande do Sul (Ref. 86734). - 
Characidae Diapoma speculiferum Cope, 1894 Fr native  Lambari (Portuguese)  4.55 cm SL male/unsexed  Known from Rio Grande do Sul (Ref. 598). Also Ref. 119400. - 
Characidae Diapoma terofali (Géry, 1964) Fr native  Lambari (Portuguese)  6.00 cm SL male/unsexed   + 
Characidae Diapoma thauma Menezes & Weitzman, 2011 Fr native   4.50 cm SL male/unsexed  Found in the tributaries of the rio Jacuí basin, northwest of Porto Alegre in Rio Grande do Sul (Ref. 86734). - 
Characidae Diapoma tipiaia (Malabarba & Weitzman, 2003) Fr native   3.55 cm SL male/unsexed  Type locality of Diapoma tipiaia, Arroio Tipiáia, ca. 13 km north of Júlio de Castilhos, on road to Cruz Alta, Rio Grande do Sul (Ref. 50838). Known from rio Jacui drainage (Ref. 55830). - 
Characidae Diapoma uruguayense (Messner, 1962) Fr native    5.10 cm SL male/unsexed  Type locality, Arroio Pai-Passo, on road Santana do Livramento-Alegrete (RS 183), Quaraí, Rio Grande do Sul (Ref. 50838). + 
Cichlidae Dicrossus filamentosus (Ladiges, 1958) Fr, Or native  Patakera (Portuguese)  3.80 cm SL male/unsexed  Occurs in northwest Brazil (Rio Negro basin). Exported to North America as an aquarium fish (Ref. 4537). + 
Cichlidae Dicrossus foirni Römer, Hahn & Vergara, 2010 Fr native   7.09 cm SL male/unsexed ;4.50 cm SL female  Known from the northern Rio drainage (Ref. 85095). + 
Cichlidae Dicrossus maculatus Steindachner, 1875 Fr endemic  Xadrez (Portuguese)   5.30 cm SL male/unsexed ;6.00 cm female  Known from the Amazon River basin, in the Tapajós River drainage, Maués River, and near Parintins (Ref. 36377). Type locality: Amazon R. drainage at Lake Maximo, Lake Jose Assu, Rio Tonantins, R. Hyavary, R. Tajapuru, Brazil (Ref. 12965). Also Ref. 12251. + 
Cichlidae Dicrossus warzeli Römer, Hahn & Vergara, 2010 Fr native   6.00 cm SL male/unsexed ;3.50 cm SL female  Known only from Tapajos River, Amazon River system. Seems to be endemic to the middle to upper Rio Tapajos system (Ref. 85095). - 
Sternopygidae Distocyclus conirostris (Eigenmann & Allen, 1942) Fr native    50.00 cm TL male/unsexed  Found in the Amazon River (Ref. 39524). - 
Doradidae Doras carinatus (Linnaeus, 1766) Fr native  Botinho (Portuguese), Cuyú cuyú (Portuguese), Mandi-serra (Portuguese)  30.00 cm SL male/unsexed  Also Ref. 35381. + 
Doradidae Doras higuchii Sabaj Pérez & Birindelli, 2008 Fr native   32.50 cm TL male/unsexed  Type locality, Rio Curuám (Iriri-Xingu Drainage), near town of Castelo dos Sonhos, 8°19'07"S, 55°05'23"W, Altamira Municipality, Pará, Brazil. + 
Doradidae Doras phlyzakion Sabaj Pérez & Birindelli, 2008 Fr native     Type locality, Rio Tefé (Amazonas Drainage), beach, Vista Escura, 3°38'S, 64°59'W, Amazonas, Brazil (Ref. 81932). - 
Doradidae Doras zuanoni Sabaj Pérez & Birindelli, 2008 Fr native    Known from the rio Araguaia (Tocantins drainage). + 
Eleotridae Dormitator maculatus (Bloch, 1792) Fr, Br native  Barrigudo (Portuguese), Cundundé (Portuguese), Dorminhoco (Portuguese)   70.00 cm TL male/unsexed  Also Ref. 26340. + 
Pimelodidae Duopalatinus emarginatus (Valenciennes, 1840) Fr, Thr endemic  Mandi urutu (Portuguese), Mandi-açu (Portuguese), Mandiaçu (Portuguese), Urutu (Portuguese)   14.00 cm SL male/unsexed  Known from São Francisco River basin (Ref. 36506). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Type locality: Rio San Francisco (Ref. 6868, 26282). + 
Pimelodidae Duopalatinus peruanus Eigenmann & Allen, 1942 Fr native    15.00 cm SL male/unsexed    - 
Auchenipteridae Duringlanis altae (Fowler, 1945) Fr native    3.55 cm SL male/unsexed    - 
Auchenipteridae Duringlanis perugiae (Steindachner, 1882) Fr native    5.00 cm SL male/unsexed  Found in the Acre and Purus River basins (Ref. 97592). + 
Sternopygidae Eigenmannia antonioi Peixoto, Dutra & Wosiacki, 2015 Fr endemic    20.46 cm TL male/unsexed  Currently known only from Rio Anapu at Floresta Nacional de Caxiuanã, a tributary of the lower portion of Rio Amazonas, state of Pará, Brazil (Ref. 115689). - 
Sternopygidae Eigenmannia besouro Peixoto & Wosiacki, 2016 Fr native   14.76 cm TL male/unsexed  Occurs in the tributaries of the left margin of rio São Francisco in Bahia, northeastern Brazil (Ref. 115976). - 
Sternopygidae Eigenmannia desantanai Peixoto, Dutra & Wosiacki, 2015 Fr endemic    18.60 cm TL male/unsexed  Currently only known from Rio Cuiabá, Rio Paraguay basin, Mato Grosso (Ref. 115689). - 
Sternopygidae Eigenmannia guairaca Peixoto, Dutra & Wosiacki, 2015 Fr endemic    17.28 cm TL male/unsexed  Currently only known from Riacho Água do Ó, a tributary of the Rio Paranapanema, upper Rio Paraná basin, Paraná, Brazil (Ref. 115689). - 
Sternopygidae Eigenmannia humboldtii (Steindachner, 1878) Fr native    48.60 cm SL male/unsexed    + 
Sternopygidae Eigenmannia limbata (Schreiner & Miranda Ribeiro, 1903) Fr native    48.50 cm TL male/unsexed  Found in the Amazon River (Ref. 39524). - 
Sternopygidae Eigenmannia macrops (Boulenger, 1897) Fr native  Sarapó (Portuguese)   25.20 cm TL male/unsexed  Found in the Amazon River (Ref. 39524). + 
Sternopygidae Eigenmannia matintapereira Peixoto, Dutra & Wosiacki, 2015 Fr native   21.98 cm TL male/unsexed  Occurs in Rio Uneiuxi and Rio Urubaxi, tributaries of the Rio Negro in Amazonas (Ref. 115689). - 
Sternopygidae Eigenmannia microstomus (Reinhardt, 1852) Fr native  Sarapó (Portuguese)  18.70 cm TL male/unsexed  Found in the upper São Francisco River basin (Ref. 39524). - 
Sternopygidae Eigenmannia muirapinima Peixoto, Dutra & Wosiacki, 2015 Fr native   14.26 cm TL male/unsexed  Occurs in Igarapé Santo Antônio and Lago Jará, both tributaries of Rio Amazonas, Rio Amazonas basin in Pará (Ref. 115689). - 
Sternopygidae Eigenmannia nigra Mago-Leccia, 1994 Fr native   47.60 cm TL male/unsexed   - 
Sternopygidae Eigenmannia pavulagem Peixoto, Dutra & Wosiacki, 2015 Fr native   26.33 cm TL male/unsexed  Occurs in small tributaries of Rio Capim, Rio Guamá basin in north-eastern Pará (Ref. 115689). - 
Sternopygidae Eigenmannia trilineata López & Castello, 1966 Fr native  Tuvira (Portuguese)   25.00 cm TL male/unsexed  Recorded from Machado river basin (Ref. 97589). + 
Sternopygidae Eigenmannia vicentespelaea Triques, 1996 Fr native  Ituí (Portuguese)   20.79 cm TL male/unsexed  Found in caves in the São Vicente River, Tocantins River basin (Ref. 39524). - 
Sternopygidae Eigenmannia virescens (Valenciennes, 1836) Fr native  Tuvira (Portuguese), Peixe-espada (Portuguese), Pestana (Portuguese), Sarapó (Portuguese), Sarapó-barrigudinho (Portuguese), Tuvira amarela (Portuguese)   44.00 cm SL male/unsexed  Occurs in the Amazon River basin, Pardo River in Paraná River basin (Ref. 27745) Uruguay River (Ref. 79585) and Acre River (Ref. 97592). Found in Córrego Barreiro (Ref. 53011). Also Ref. 39524. + 
Sternopygidae Eigenmannia waiwai Peixoto, Dutra & Wosiacki, 2015 Fr native   22.41 cm TL male/unsexed  Occurs in Rio Mapuera, a tributary of the Rio Trombetas basin, Pará (Ref. 115689). - 
Crenuchidae Elachocharax geryi Weitzman & Kanazawa, 1978 Fr native   1.90 cm SL male/unsexed  Known from the Negro River basin (Ref. 37059). Museum: Lago Paricatuba, Rio Negro drainage, Estado do Amazonas, MZUSP 13249 (holotype, 1.9 cm SL) (Ref. 13683). Also Ref. 27925. - 
Crenuchidae Elachocharax junki (Géry, 1971) Fr native    2.31 cm SL male/unsexed  Recorded from Amazon, Cuieiras, Novo and Madeira rivers. Museum : Rio Novo, 8°46'S, 63°30'W, No. 0624 J. Gèry's personal collection (holotype, 2.24 cm SL) (Ref. 13683). Also Ref. 598, 37059. - 
Crenuchidae Elachocharax mitopterus Weitzman, 1986 Fr native   1.39 cm SL male/unsexed  Known from the Negro River basin (Ref. 37059). Museum: Igarapé Tarumazinho, Amazon, MZUSP 29871 (Ref. 27925). - 
Crenuchidae Elachocharax pulcher Myers, 1927 Fr native    2.21 cm SL male/unsexed  Known from the Amazon (Ref. 37059) and Machado River basin (Ref. 97589). Recorded from Igarapé Açu at Aveiro, Estado do Para (Ref. 13683). + 
Gymnotidae Electrophorus electricus (Linnaeus, 1766) Fr questionable  Poraquê (Portuguese), Enguia elétrica (Portuguese), Peixe elétrico (Portuguese), Pixundé (Portuguese), Poraquê de fogo (Portuguese), Puraquê (Portuguese), Puxundu (Portuguese), Treme treme (Portuguese)   250 cm SL male/unsexed  Reported from the Amazon River (Ref. 36692). Part of the Guiana Shield; but needs further confirmation. + 
Gymnotidae Electrophorus varii de Santana, Wosiacki, Crampton, Sabaj, Dillman, Mendes-Júnior & Castro e Castro, 2019 Fr native   149 cm TL male/unsexed  Type locality of Electrophorus varii,Pará, Marajó I., Goiapi River. Collected from Acapu, Caripetuba, Curiaú, Curuá, Goiapi (tributary of rio Arari), Irituia, Maicuru rivers (Pará State); Matupiri, Solimões, Rio Negro/Solimoes rivers (Amazon State); Rio Tapajós (Mato Grosso State); Itapecuru and Marmorana (Maranhão State); the Purus River a tributary of the Amazon River (Ref. 120918). - 
Gymnotidae Electrophorus voltai de Santana, Wosiacki, Crampton, Sabaj, Dillman, Castro e C., Bastos & Vari, 2019 Fr native   171 cm TL male/unsexed  Type locality of Electrophorus voltai, Pará, Almerim, Ipitinga River. Collected from Cupari, Curiaú, Maicuru, São Benedito rivers (Pará State); Teles Pires and Xingu rivers (includes Iriri River) in Mato Grosso and Pará states; Tapajós river (Mato Grosso); Santa Rosa (Rio Grande do Sul State); Rossevelt River (Rondônia State) (Ref. 120918). - 
Eleotridae Eleotris pisonis (Gmelin, 1789) Fr, Br, M native  Peixe-macaco (Portuguese), Amoré-pixuna (Portuguese), Amoré-preto (Portuguese), Amorepixuna (Portuguese), Moré-preto (Portuguese)   25.00 cm TL male/unsexed  Also Ref. 26938. + 
Triportheidae Engraulisoma taeniatum Castro, 1981 Fr native    4.20 cm SL male/unsexed  Museum: Rio Cuiabá, Mato Grosso, MZUSP 14704 (holotype of E. taeniatum, 4.1 cm SL) (Ref. 27925). Also Ref. 38376. - 
Auchenipteridae Entomocorus benjamini Eigenmann, 1917 Fr native    7.00 cm SL male/unsexed    + 
Auchenipteridae Entomocorus melaphareus Akama & Ferraris, 2003 Fr native   5.86 cm SL male/unsexed  Known only from two localities on the left bank of the Amazon River below Manaus (Ref. 54767). - 
Auchenipteridae Entomocorus radiosus Reis & Borges, 2006 Fr native   5.29 cm SL male/unsexed  Known from the upper Paraguay River. Found in Pantanal (Ref. 57707). - 
Loricariidae Epactionotus bilineatus Reis & Schaefer, 1998 Fr native    4.00 cm SL male/unsexed  Recorded from Rio Grande do Sul State: Rios Maquiné and Três Forquilhas. + 
Loricariidae Epactionotus gracilis Reis & Schaefer, 1998 Fr native   3.90 cm SL male/unsexed  Recorded from Santa Catarina State: Rio Araranguá. - 
Loricariidae Epactionotus itaimbezinho Reis & Schaefer, 1998 Fr native   3.80 cm SL male/unsexed  Recorded from Rio Mampituba. - 
Loricariidae Epactionotus yasi Almirón, Azpelicueta & Casciotta, 2004 Fr native       - 
Auchenipteridae Epapterus dispilurus Cope, 1878 Fr native    15.40 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 37098). - 
Aspredinidae Ernstichthys taquari Dagosta & de Pinna, 2021 Fr native   2.28 cm SL male/unsexed  Type locality of Ernstichthys taquari, Mato Grosso do Sul, Alcinópolis, Rio Taquarizinho (tributary to rio Taquari, rio Paraguay drainage). It was not locally abundant at the time of collection, with only three specimens found in the course of five hours of collecting effort (Ref. 124573). - 
Erythrinidae Erythrinus erythrinus (Bloch & Schneider, 1801) Fr native  Iú (Portuguese), Jeju (Portuguese), Jejú (Portuguese), Mariana (Portuguese), Moroba (Portuguese), Morobá (Portuguese)   20.00 cm SL male/unsexed  Found in Machado (Ref. 97589) and Acre River basins (Ref. 97592). Museum: near Pará, USNM 163759. Upper Rio Juruena, Mato Grosso, USNM 199203. + 
Erythrinidae Erythrinus kessleri Steindachner, 1877 Fr native   19.00 cm SL male/unsexed   - 
Characidae Erythrocharax altipinnis Netto-Ferreira, Birindelli, de Sousa, Mariguela & Oliveira, 2013 Fr native   2.62 cm SL male/unsexed  Known from Rio Curuá at Serra do Cachimbo, Pará (Ref. 93035) - 
Gerreidae Eucinostomus argenteus Baird & Girard, 1855 Fr, Br, M native  Carapicu-pena (Portuguese), Acarapicu (Portuguese), Carapeba (Portuguese), Carapicu (Portuguese), Carapipiacuaçu (Portuguese), Escrivão (Portuguese)  21.20 cm TL male/unsexed 13.5 TL Ranges from Paraíba south to Santa Catarina (Ref. 57756). Also Ref. 7251, 13442, 26938, 55758. Caught by shrimp trawl in Pirambu, Sergipe (Ref. 118626). + 
Gerreidae Eugerres plumieri (Cuvier, 1830) Fr, Br, M native  Carapeba-listrada (Portuguese), Carapeba-rajada (Portuguese), Caratinga (Portuguese)  40.00 cm TL male/unsexed  Also Ref. 26340. + 
Loricariidae Eurycheilichthys limulus Reis & Schaefer, 1998 Fr native   4.80 cm SL male/unsexed  Recorded from Rio Grande do Sul State: Rio Jacuí. - 
Loricariidae Eurycheilichthys pantherinus (Reis & Schaefer, 1992) Fr native   4.20 cm SL male/unsexed  Known from the upper and middle Uruguay River basin (Ref. 36885). Museum: creek tributary of Rio Dos Touros, Rio Grande do Sul, 250 to 500 m elevation, MCP 13077 (holotype, 3.79 cm SL) (Ref. 26607). - 
Loricariidae Euryochus thysanos Pereira & Reis, 2017 Fr native   11.97 cm SL male/unsexed  Found in the coastal rivers of eastern Brazil from Itapemirim River in the south, and including the larger basins of the Doce and Mucuri rivers in Espirito Santo and Minas Gerais states, to the Frades River in the north, in Bahia State (Ref. 116743). - 
Gobiidae Evorthodus lyricus (Girard, 1858) Fr, Br, M native  Amoré (Portuguese), Maria-da-toca (Portuguese)   15.00 cm TL male/unsexed   + 
Pimelodidae Exallodontus aguanai Lundberg, Mago-Leccia & Nass, 1991 Fr native    20.00 cm SL male/unsexed    + 
Loricariidae Exastilithoxus hoedemani Isbrücker & Nijssen, 1985 Fr native   5.10 cm SL male/unsexed  Known from Maurauiá River in the upper Negro River drainage (Ref. 36713). - 
Characidae Exodon paradoxus Müller & Troschel, 1844 Fr native  Miguelinho (Portuguese)   7.50 cm SL male/unsexed  Known from the Amazon and Tocantins River basins (Ref. 38376). Also Ref. 4537. + 
Loricariidae Farlowella amazonum (Günther, 1864) Fr native  Acarí espada (Portuguese), Cascudo espada (Portuguese)   22.50 cm SL male/unsexed  Known from the Amazon and Tocantins River basins (Ref. 36389). Also Ref. 6868. + 
Loricariidae Farlowella gianetii Ballen, Pastana & Peixoto, 2016 Fr native   12.10 cm SL male/unsexed  Type locality of Farlowella gianetii: rio Couto de Magalhães, rio Xingu basin, Campinápolis, Mato Grosso (Ref. 128466). - 
Loricariidae Farlowella hahni Meinken, 1937 Fr native    20.10 cm SL male/unsexed   + 
Loricariidae Farlowella hasemani Eigenmann & Vance, 1917 Fr native    17.00 cm SL male/unsexed  Found in Pará State (Ref. 36389). - 
Loricariidae Farlowella henriquei Miranda Ribeiro, 1918 Fr native   16.50 cm SL male/unsexed  Known from the Araguaia River basin (Ref. 36389). - 
Loricariidae Farlowella isbruckeri Retzer & Page, 1997 Fr native   13.40 cm SL male/unsexed  Known from tne Paraguay River basin (Ref. 36389). - 
Loricariidae Farlowella jauruensis Eigenmann & Vance, 1917 Fr native   13.10 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 36389). - 
Loricariidae Farlowella nattereri Steindachner, 1910 Fr native    26.50 cm SL male/unsexed  Found in the Amazon River basin (Ref. 36389). + 
Loricariidae Farlowella oxyrryncha (Kner, 1853) Fr native    23.00 cm SL male/unsexed  Found in the Amazon River and coastal rivers of northeastern Brazil (Ref. 36389). - 
Loricariidae Farlowella paraguayensis Retzer & Page, 1997 Fr native    17.50 cm SL male/unsexed  Found in the Paraguay River (Ref. 36389). + 
Loricariidae Farlowella platorynchus Retzer & Page, 1997 Fr native   19.40 cm SL male/unsexed  Found in the Amazon River (Ref. 36389). + 
Loricariidae Farlowella schreitmuelleri Ahl, 1937 Fr native   18.10 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36389). - 
Loricariidae Farlowella smithi Fowler, 1913 Fr native    10.00 cm SL male/unsexed  Found in the Madeira River basin (Ref. 36389). - 
Loricariidae Farlowella vittata Myers, 1942 Fr native    22.50 cm SL male/unsexed    + 
Loricariidae Farlowella wuyjugu Dopazo, Wosiacki & Britto, 2023 Fr native   14.47 cm SL male/unsexed  Type locality of the holotype of Farlowella wuyjugu: igarape Rio Branco, rio Amazon basin, lower rio Tapajos, Juruti municipality (Ref. 128687). - 
Auchenipteridae Ferrarissoaresia ferrarisi (Birindelli, Sarmento-Soares & Lima, 2015) Fr native   7.06 cm SL male/unsexed  Found only in a headwater of Rio das Balsas, a tributary of the Rio do Sono, middle Rio Tocantins basin, Tocantins state (Ref. 104786). - 
Auchenipteridae Ferrarissoaresia meridionalis (Sarmento-Soares, Cabeceira, Carvalho, Zuanon & Akama, 2013) Fr native   6.16 cm SL male/unsexed  Known only from the headwater streams of the upper reaches of rio Tapajós, at the rio Teles Pires in Mato Grosso State (Ref. 94696). - 
Fluviphylacidae Fluviphylax gouldingi Bragança, 2018 Fr native   1.43 cm SL male/unsexed ;1.39 cm SL female  Type locality of Fluviphylax gouldingi, Estado do Amazonas: Município de São Gabriel da Cachoeira: igarapé near Monte Cristo community, a tributary of Rio Vaupés drainage, upper Rio Negro drainage, Rio Amazonas, basin. Known from four main river drainages of the upper and middle Rio Negro drainage: Vaupés, Urubaxi, Neuixi and Aiuanã (Ref. 123788), - 
Fluviphylacidae Fluviphylax obscurus Costa, 1996 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  1.73 cm SL male/unsexed  Found in Rio Negro. - 
Fluviphylacidae Fluviphylax palikur Costa & Le Bail, 1999 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  2.40 cm TL male/unsexed  Museum: Estado do Amapá, Rio Taparabu, right tributary of rio Oiapoque, Juminán, MZUSP 52941 (holotype of F. palikur, 1.2 cm SL, male) (Ref. 33375). - 
Fluviphylacidae Fluviphylax pygmaeus (Myers & Carvalho, 1955) Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)   2.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 50894). Found in Rio Madeira basin, between Borba, Estado do Amazonas, and mouth of Rio Machado, Estado de Rondônia (Ref. 26652). + 
Fluviphylacidae Fluviphylax simplex Costa, 1996 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  1.60 cm SL male/unsexed  Found in Rio Solimoes-Amazonas, between lago Miuá (Codajás) and mouth of Rio Tapajós, and lower rios Trobetas and Tapajós. - 
Fluviphylacidae Fluviphylax wallacei Bragança, 2018 Fr native   1.48 cm SL male/unsexed ;1.26 cm SL female  Type locality of Fluviphylax wallacei, Estado do Amazonas: Município de Barcelos: Igarapé Mauaú near Romão community, Rio Aracá drainage, middle Rio Negro drainage. Known from two localities in the middle Rio Negro drainage, the Igarapé Mauaú in the Rio Aracá subdrainage and the Igarapé do Campo in the Rio Jufari subdrainage (Ref. 123788). - 
Fluviphylacidae Fluviphylax zonatus Costa, 1996 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  1.60 cm SL male/unsexed  Found in the lower Rio Negro, between Anavilhanas and Manaus. - 
Doradidae Franciscodoras marmoratus (Lütken, 1874) Fr native  Caborje (Portuguese), Bacu pedra (Portuguese), Bozó (Portuguese), Caboge (Portuguese), Caboje (Portuguese), Caborge (Portuguese), Combó (Portuguese), Mandim armado (Portuguese), Serrudo (Portuguese), Vasconcellos (Portuguese), Vasconcelos (Portuguese)  36.00 cm TL male/unsexed  Found in the Rio das Velhas (Ref. 6868). Known from São Francisco River basin (Ref. 37054). + 
Loricariidae Furcodontichthys novaesi Rapp Py-Daniel, 1981 Fr native    10.20 cm SL male/unsexed  Found in the Solimões River basin (Ref. 36389). - 
Characidae Galeocharax gulo (Cope, 1870) Fr native  Cacunda (Portuguese), Dentusca (Portuguese), Peixe-cachorro (Portuguese)   18.80 cm SL male/unsexed ;25.00 cm SL female  Known from Rio São Francisco and Amazon River basins (Ref. 36811). - 
Characidae Galeocharax humeralis (Valenciennes, 1834) Fr native  Saicanga (Portuguese), Peixe-cachorro (Portuguese)   30.60 cm TL male/unsexed  Reported from the Uruguay River (Ref. 79585). - 
Characidae Galeocharax knerii (Steindachner, 1879) Fr, Fi native  Peixe cadela (Portuguese), Peixe-cadela (Portuguese), Peixe-cigarra (Portuguese), Saicanga (Portuguese)   33.10 cm SL male/unsexed 16 TL Known from the upper Paraná (Ref. 36811) and Piracicaba river (Ref. 50076). Also Ref. 31923. + 
Gasteropelecidae Gasteropelecus levis (Eigenmann, 1909) Fr native  Borboleta branca (Portuguese), Peixe borboleta (Portuguese)  3.53 cm SL male/unsexed  Known from the lower Amazon River basin (Ref. 39056). Also Ref. 7020. + 
Gasteropelecidae Gasteropelecus sternicla (Linnaeus, 1758) Fr native  Borboleta (Portuguese), Sapopema (Portuguese), Voador (Portuguese)   3.90 cm SL male/unsexed  Found in Fantanal, Paraguay (Ref. 81048) and Acre River basins (Ref. 97592). + 
Auchenipteridae Gelanoglanis nanonocticolus Soares-Porto, Walsh, Nico & Netto, 1999 Fr native   2.22 cm SL male/unsexed  Known from the middle rio Negro, Amazon River basin at Paraná do Jacaré (Ref. 32901). - 
Auchenipteridae Gelanoglanis pan Calegari, Reis & Vari, 2014 Fr native   2.47 cm SL male/unsexed  Known from the rio Teles Pires, a tributary to the upper rio Tapajós basin (Ref. 97849). - 
Ariidae Genidens planifrons (Higuchi, Reis & Araújo, 1982) Fr, Br, M native  Bagre (Portuguese), Bagre-boca-larga (Portuguese)  57.00 cm SL male/unsexed   + 
Cichlidae Geophagus altifrons Heckel, 1840 Fr native    26.50 cm TL male/unsexed  Found in the tributaries of the Amazon River basin (Ref. 36377). Present in the Rio Tapajos (Ref. 52307). + 
Cichlidae Geophagus argyrostictus Kullander, 1991 Fr endemic    24.20 cm TL male/unsexed  Known from the Amazon River basin, in the Xingu River from Cachoeira von Martius to Belo Monte, and in the Curuá River (Ref. 36377). Also Ref. 12251. + 
Cichlidae Geophagus brasiliensis (Quoy & Gaimard, 1824) Fr native  Acará-topete (Portuguese), Acará (Portuguese), Acará diadema (Portuguese), Acará ferreira (Portuguese), Acará-roque (Portuguese), Acará-topête (Portuguese), Acaraí (Portuguese), Cará (Portuguese), Caratinga (Portuguese), Papa-terra (Portuguese)   28.00 cm TL male/unsexed  Recorded from the Patos lagoon (Ref. 58359). Found in the Uruguay River (Ref. 79585). + 
Cichlidae Geophagus camopiensis Pellegrin, 1903 Fr native  Acara tinga (Portuguese), Carà (Portuguese)   17.50 cm SL male/unsexed    + 
Cichlidae Geophagus diamantinensis Mattos, Costa & Santos, 2015 Fr endemic   7.41 cm SL male/unsexed  Currently known only from the upper section of the Paraguaçu river basin, Chapada Diamantina, north-eastern Brazil (Ref. 118113). - 
Cichlidae Geophagus iporangensis Haseman, 1911 Fr endemic    12.20 cm SL male/unsexed  Known from the Ribeira de Iguape River basin (Ref. 36377). + 
Cichlidae Geophagus itapicuruensis Haseman, 1911 Fr endemic     Known from the Itapicuru River, on the coast of Bahia (Ref. 36377). - 
Cichlidae Geophagus megasema Heckel, 1840 Fr native    18.90 cm SL male/unsexed  Known from the Amazon River basin in the Guaporé River basin (Ref. 36377). Recorded from Machado river basin (Ref. 97589). + 
Cichlidae Geophagus mirabilis Deprá, Kullander, Pavanelli & Graça, 2014 Fr native   16.21 cm SL male/unsexed  Known from the rio Aripuanã drainage, upstream from Dardanelos/Andorinhas falls (Ref. 102658). - 
Cichlidae Geophagus multiocellus Mattos & Costa, 2018 Fr native   10.29 cm SL male/unsexed  Type locality of Geophagus multiocellus, Bahia state: Iguaí municipality: Guaíra balneary, Rio Cambiriba, Rio Gongogi drainage, Rio de Contas Basin. Known only from the middle section of the Rio de Contas Basin, about 270 to 545 m above sea level, Bahia state, northeast Brazil (Ref. 119412). + 
Cichlidae Geophagus neambi Lucinda, Lucena & Assis, 2010 Fr native   20.30 cm SL male/unsexed ;19.20 cm SL female   - 
Cichlidae Geophagus obscurus (Castelnau, 1855) Fr native    10.00 cm SL male/unsexed  Known from Paraguaçu River in the coast of Bahia (Ref. 36377). + 
Cichlidae Geophagus parnaibae Staeck & Schindler, 2006 Fr native   7.59 cm SL male/unsexed  Known from the rio Parnaíba drainage in Piauí and Maranhão, northeastern Brazil (Ref. 57445). + 
Cichlidae Geophagus proximus (Castelnau, 1855) Fr, Fi native  Acará roi roi (Portuguese), Acará tinga (Portuguese), Acará-papa-terra (Portuguese), Acaratinga (Portuguese)   34.80 cm TL male/unsexed ;26.60 cm female  Found along the Solimoes-Amazon River to the Trombetas River (Ref. 36377). Widespread in Brazilian waters, including the rivers Tefe and Trombetas (Ref. 12251). Found in fish markets in Santarém (Ref. 12202). + 
Cichlidae Geophagus rufomarginatus Mattos & Costa, 2018 Fr native   10.41 cm male/unsexed  Type locality of Geophagus rufomarginatus, NE Brazil, Bahia State: Porto Seguro municipality: small stream crossing the road BA-001, Rio Buranhém Basin. Known only from Known only from the middle and lower sections of the Rio Buranhém Basin, at altitudes of about 65 m above sea level or less (Ref. 119412). + 
Cichlidae Geophagus santosi Mattos & Costa, 2018 Fr native   15.34 cm SL male/unsexed  Type locality of Geophagus santosi, Bahia state: Ituberá municipality: Rio Mariana upstream of Cachoeira da Pancada, Área de Proteção Ambiental Michelin. Known only from the Rio Mariana, an isolated small coastal river of Bahia state, northeast Brazil (Ref. 119412). + 
Cichlidae Geophagus surinamensis (Bloch, 1791) Fr misidentification  Acará tinga (Portuguese), Acará (Portuguese), Acará-bicudo (Portuguese), Acará-pitanga (Portuguese), Cará (Portuguese), Cará de praia (Portuguese), Cará roe roe (Portuguese), Cará tabaco doido (Portuguese), Juquiá (Portuguese)   14.80 cm SL male/unsexed  Recorded from the country (Ref. 6029). Occurrence in the country is not confirmed (Ref. 36377). + 
Cichlidae Geophagus sveni Lucinda, Lucena & Assis, 2010 Fr native   16.70 cm SL male/unsexed   - 
Gerreidae Gerres cinereus (Walbaum, 1792) Fr, Br, M native  Carapicu-açú (Portuguese), Carapeba (Portuguese)  41.00 cm TL male/unsexed  Also Ref. 26340. + 
Heptapteridae Gladioglanis anacanthus Rocha, de Oliveira & Rapp Py-Daniel, 2008 Fr native   2.63 cm SL male/unsexed  Known only from its type locality, Lago do Mamão, rio Aripuanã basin in Amazonas state (Ref. 79081). - 
Heptapteridae Gladioglanis conquistador Lundberg, Bornbusch & Mago-Leccia, 1991 Fr native    3.90 cm SL male/unsexed  Occurs in the Solimões, Purus, and Capim River basins (Ref. 36914). - 
Heptapteridae Gladioglanis machadoi Ferraris & Mago-Leccia, 1989 Fr native   3.40 cm SL male/unsexed  Occurs in the Negro River basin (Ref. 36914). - 
Trichomycteridae Glanapteryx anguilla Myers, 1927 Fr native   6.14 cm TL male/unsexed  Known from the Negro River basin (Ref. 39970). Type locality: Rapids of Sao Gabriel, Rio Negro system, Brazil (Ref. 26282, 6868). - 
Trichomycteridae Glanapteryx niobium de Pinna, 1998 Fr native   5.53 cm male/unsexed  Known from Morro dos Seis Lagos, Negro River basin (Ref. 39970). - 
Characidae Glandulocauda caerulea Menezes & Weitzman, 2009 Fr native    4.39 cm SL male/unsexed  Known from the Iguaçu River basin (Ref. 38597). Type locality, Rio Iguaçu at Serrinha Paraná, (Ref. 30296). - 
Characidae Glandulocauda melanopleura (Ellis, 1911) Fr native  Lambari (Portuguese)   5.50 cm SL male/unsexed  Found in the upper Tietê River of the upper Paraná basin and adjoining upper portions of the coastal rivers Guaratuba, Itatinga and Ribeira de Iguape flowing into the Atlantic Ocean in the State of São Paulo. Also Ref. 38376. - 
Auchenipteridae Glanidium albescens Lütken, 1874 Fr native  Anduiá (Portuguese), Bagre branco (Portuguese), Bagrinho de água doce (Portuguese), Bocudo (Portuguese), Buneva (Portuguese), Bureva (Portuguese), Enduiá (Portuguese), Jundiá (Portuguese), Pacamão branco (Portuguese), Pacu branco (Portuguese), Peixe-dourado (Portuguese)  12.15 cm SL male/unsexed  Found in the Rio das Velhas (Ref. 6868). + 
Auchenipteridae Glanidium botocudo Sarmento-Soares & Martins-Pinheiro, 2013 Fr native    9.55 cm SL male/unsexed  Found in large coastal river systems such as Rio Doce and Rio Mucuri in Minas Gerais (Ref. 93811). - 
Auchenipteridae Glanidium catharinensis Miranda Ribeiro, 1962 Fr native   15.80 cm SL male/unsexed  Known from Tubarão River basin in Santa Catarina (Ref. 37098). Found in the Rio do Braco do Norte, São Ludgero in Sta. Catarina (Ref. 6868). - 
Auchenipteridae Glanidium cesarpintoi Ihering, 1928 Fr native   9.57 cm SL male/unsexed  Known from Mogi-guassú River basin, São Paulo (Ref. 37098). - 
Auchenipteridae Glanidium melanopterum Miranda Ribeiro, 1918 Fr native    19.00 cm SL male/unsexed  Found in Piquete, São Paulo (Ref. 6868). - 
Auchenipteridae Glanidium ribeiroi Haseman, 1911 Fr native  Jundiá miúdo (Portuguese)   22.00 cm SL male/unsexed  Found in the Rio Iguassu, Porto União da Vitoria, Paraná (Ref. 6868). - 
Trichomycteridae Glaphyropoma rodriguesi de Pinna, 1992 Fr native   5.07 cm SL male/unsexed  Known from the Mucujê River, tributary of Paraguaçu River (Ref. 37790). - 
Trichomycteridae Glaphyropoma spinosum Bichuette, de Pinna & Trajano, 2008 Fr native   5.82 cm SL male/unsexed   - 
Acestrorhynchidae Gnathocharax steindachneri Fowler, 1913 Fr native    5.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36811). Also Ref. 598. + 
Gobiidae Gobioides grahamae Palmer & Wheeler, 1955 Fr, Br, M native   17.30 cm SL male/unsexed  Museum: Marajo I., BMNH 1925.10.28.464 (holotype of G. unicolor and G. grahamae); BMNH 1925.10.28.465 (paratype) (Ref. 27974). Also Ref. 50190. + 
Gobiidae Gobionellus oceanicus (Pallas, 1770) Fr, Br native  Amborê (Portuguese), Amoré (Portuguese), Boca-de-fogo (Portuguese), Boca-de-ouro (Portuguese), Corongo (Portuguese), Maria-da-toca (Portuguese), Milonga (Portuguese), Milongo (Portuguese), Mingula (Portuguese), Miroró (Portuguese), Miroró mirim (Portuguese), Moré (Portuguese), Moré-boca-de-ouro (Portuguese), Moré-de-areia (Portuguese), Mororó (Portuguese), Muré (Portuguese), Taissica (Portuguese)  27.00 cm TL male/unsexed   + 
Heptapteridae Goeldiella eques (Müller & Troschel, 1849) Fr native  Caiauaná (Portuguese)  28.90 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36914). + 
Cichlidae Guianacara geayi (Pellegrin, 1902) Fr native  Carà (Portuguese)  12.40 cm TL male/unsexed  Known from the Oyapock River drainage (Ref. 36377). + 
Loricariidae Guyanancistrus teretirostris Fisch-Muller, Mol & Covain, 2018 Fr native   9.76 cm SL male/unsexed  Found only in the upper Kumbu Creek in the Brownsberg Nature Park, Brownsberg Mountains, at altitude 200±430 m above mean sea level (Ref. 116863). - 
Characidae Gymnocorymbus flaviolimai Benine, Melo, Castro & Oliveira, 2015 Fr native   5.15 cm SL male/unsexed  Known from the Rio Madeira of the Amazon basin (Ref. 101636). - 
Characidae Gymnocorymbus ternetzi (Boulenger, 1895) Fr native  Tetra preto (Portuguese), Tetra-negro (Portuguese), Tetra-preto (Portuguese)   7.50 cm SL male/unsexed  Occurs in southern Brazil (Ref. 38376); recorded from rio Paraguai basin, Santo Antônio do Leverger, Mato Grosso, MZUSP 18720 (Ref. 46237) + 
Characidae Gymnocorymbus thayeri Eigenmann, 1908 Fr native  Lambari (Portuguese)   7.40 cm SL male/unsexed  Recorded from igarapé Caxipacoré, rio Trombetas, Pará, INPA 12231 (Ref. 46237). + 
Cichlidae Gymnogeophagus balzanii (Perugia, 1891) Fr native  Cará (Portuguese)   12.00 cm SL male/unsexed  Known from the Paraguay drainage of the Paraná River basin and the lower Uruguay drainage (Ref. 36377). + 
Cichlidae Gymnogeophagus constellatus Malabarba, Malabarba & Reis, 2015 Fr native   13.68 cm SL male/unsexed  Type locality of Gymnogeophagus constellatus Rio Grande do Sul, Ijuí, rio Conceição (Ref. 118066). - 
Cichlidae Gymnogeophagus gymnogenys (Hensel, 1870) Fr native  Cará (Portuguese)   15.00 cm SL male/unsexed  Restricted to the laguna dos Patos and rio Tramandaí drainages in Rio Grande do Sul (Ref. 118066). Questionable occurrence in Lagoa Mirim drainages (Ref. 36377) and Uruguay River (Ref. 79585), probably misidentification (see Ref. 118066). Also Ref. 36377. + 
Cichlidae Gymnogeophagus labiatus (Hensel, 1870) Fr native  Cará (Portuguese)   15.20 cm SL male/unsexed  Known from Laguna dos Patos and Lagoa Mirim drainages (Ref. 36377). + 
Cichlidae Gymnogeophagus lacustris Reis & Malabarba, 1988 Fr endemic    14.60 cm SL male/unsexed  Found in coastal drainages in northern Rio Grande do Sul (Ref. 36377). Type locality: canal between Lagoa da Cerquinha and Lagoa da Rondinha, Pinhal, Tramandai, RS (Ref. 36377). - 
Cichlidae Gymnogeophagus lipokarenos Malabarba, Malabarba & Reis, 2015 Fr native   12.34 cm SL male/unsexed  Type locality of Gymnogeophagus lipokarenos, rio Dourados at Linha Várzea, on road from Severiano de Almeida to Aratiba, Rio Grande do Sul, Brazil (Ref. 118066). - 
Cichlidae Gymnogeophagus mekinos Malabarba, Malabarba & Reis, 2015 Fr native   10.45 cm SL male/unsexed  Type locality of Gymnogeophagus mekinos, Rio Grande do Sul, rio Piraizinho, on road from Bagé to Dom Pedrito, tributary of rio Negro. It inhabits the río Negro, connected to the lower río Uruguay. Report of its presence in the río Tacuarí / lagoa Mirim drainage is probably based on a study using DNA analysis (Ref. 118066). + 
Cichlidae Gymnogeophagus meridionalis Reis & Malabarba, 1988 Fr native    9.50 cm SL male/unsexed  Known from the Uruguay River drainage (Ref. 36377). + 
Cichlidae Gymnogeophagus missioneiro Malabarba, Malabarba & Reis, 2015 Fr native   10.93 cm SL male/unsexed  Type locality of Gymnogeophagus missioneiro, Rio Grande do Sul, 4 km from São Luiz Gonzaga, arroio Ximbocuzinho, on road from São Luiz Gonzaga to Bossoroca. It is known from the rio Piratini and its tributaries, middle rio Uruguay basin, in the western portion of Rio Grande do Sul (Ref. 118066). - 
Cichlidae Gymnogeophagus pseudolabiatus Malabarba, Malabarba & Reis, 2015 Fr native  abundant (always seen in some numbers) 9.59 cm SL male/unsexed  Type locality of Gymnogeophagus pseudolabiatus<>, Rio Grande do Sul, Santana do Livramento, rio Sarandi III, tributary of rio Quaraí, a tributary of rio Uruguay on road from Santana do Livramento to Quaraí. Known from the rio Quaraí and its tributaries, along the border of Brazil. This species is relatively frequent and abundant in the rio Quaraí basin (Ref. 118066). Status of threat: Least Concern: Extent of Occurrence (EOO) is approximately 4,500 square kilometers and no specific threats were detected (Ref. 118066). - 
Cichlidae Gymnogeophagus rhabdotus (Hensel, 1870) Fr native  Cará (Portuguese)   12.00 cm SL male/unsexed  Known from the Laguna dos Patos basin (Ref. 36377). Also Ref. 4537. + 
Cichlidae Gymnogeophagus setequedas Reis, Malabarba & Pavanelli, 1992 Fr native  Acará (Portuguese)   9.80 cm SL male/unsexed  Found in the Paraná River basin (Ref. 36377). Known from the Pantanal of Brazil coming in with the floodwaters of the Rio Paraguay (Ref. 12251). - 
Rhamphichthyidae Gymnorhamphichthys hypostomus Ellis, 1912 Fr native    21.50 cm TL male/unsexed    - 
Rhamphichthyidae Gymnorhamphichthys petiti Géry & Vu, 1964 Fr native     Known from the Upper Araguaia River (Ref. 36685), Machado (Ref. 97589) and Acre River basins (Ref. 97592). - 
Rhamphichthyidae Gymnorhamphichthys rondoni (Miranda Ribeiro, 1920) Fr native    15.00 cm TL male/unsexed    + 
Rhamphichthyidae Gymnorhamphichthys rosamariae Schwassmann, 1989 Fr native    Known from Negro River basin (Ref. 36685). - 
Loricariidae Gymnotocinclus anosteos Carvalho, Lehmann A. & Reis, 2008 Fr native   4.43 cm SL male/unsexed   - 
Gymnotidae Gymnotus anguillaris Hoedeman, 1962 Fr native  Ituï (Portuguese), Carapo (Portuguese), Sarapo (Portuguese), Tuvira (Portuguese)   30.00 cm SL male/unsexed    + 
Gymnotidae Gymnotus arapaima Albert & Crampton, 2001 Fr native   55.00 cm TL male/unsexed  Type locality: Amazonas: Paraná Apara, 10 km NW confluence Juruá and Solimões rivers, Mamirauá Reserve (Ref. 41292). - 
Gymnotidae Gymnotus bahianus Campos-da-Paz & Costa, 1996 Fr native    27.60 cm TL male/unsexed  Known only from its type locality and surrounding areas, all near Ilhéus, Bahia State. - 
Gymnotidae Gymnotus capanema Milhomem, Crampton, Pierczeka, Shetka, Silva & Nagamachi, 2012 Fr native   17.90 cm TL male/unsexed  Type locality, Pará State, municipality of Capanema, Açaiteuazinho River, (tributary of Amazon Estuary), MPEG 15170 (holotype og Gymnotus capanema, 17.9 cm TL, male). Found in drainages of the Amazon Estuary in the state of Pará, Brazil (Rio Açaiteuazinho drainage near the town of Capanema and in the Rio Caeté near the town of Bragança). A single lot found from an unlisted drainage in the municipality of Santa Isabel do Pará indicates that this species is also found some 100 km east of the type locality near Capanema (Ref. 89487). - 
Gymnotidae Gymnotus capitimaculatus Rangel-Pereira, 2014 Fr native  scarce (very unlikely) 15.84 cm TL male/unsexed  Known only from the rio do Ouro, a tributary of the rio Jucuruçu, Itamaraju municipality in Bahia state, northeastern Brazil. This is the only population belonging to the Gymnotus pantherinus species group found in this basin or in its neighboring, indicating that this is a very rare and endangered species (Ref. 96661). - 
Gymnotidae Gymnotus carapo Linnaeus, 1758 Fr, Fi native  Tuvira (Portuguese), Carapo (Portuguese), Carapó (Portuguese), Ituí (Portuguese), Ituï (Portuguese), Morenita (Portuguese), Peixe espada do rio (Portuguese), Pirá mboi (Portuguese), Sabão (Portuguese), Sarapo (Portuguese), Sarapó (Portuguese), Tira faca (Portuguese), Tuí (Portuguese), Varapó (Portuguese) scarce (very unlikely) 76.00 cm TL male/unsexed 14.6 TL Recorded from the Pardo River (Ref. 27745), Caracu and Sao Pedro streams, tributaries of the Paraná River (Ref. 26076), Pircacicaba (Ref. 50076), Machado (Ref. 97589) and Uruguay River (Ref. 79585). Also Ref. 36692. + 
Gymnotidae Gymnotus cataniapo Mago-Leccia, 1994 Fr native   31.60 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36692). + 
Gymnotidae Gymnotus chimarrao Cognato, Richer-de-Forges, Albert & Crampton, 2008 Fr native   24.30 cm TL male/unsexed  Type locality, Arroio Grande in the Rio Taquari drainage, Arroio do Meio, Rio Grande do Sul, UFRGS 6774 (holotype of Gymnotus chimarrao, 11.84 cm SL, immature male) (Ref. 75065). - 
Gymnotidae Gymnotus coatesi La Monte, 1935 Fr native    30.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36692). - 
Gymnotidae Gymnotus coropinae Hoedeman, 1962 Fr native    34.50 cm SL male/unsexed  Recorded from Machado (Ref. 97589) and Acre River basin (Ref. 97592). + 
Gymnotidae Gymnotus cuia Craig, Malabarba, Crampton & Albert, 2018 Fr native   30.50 cm TL male/unsexed   - 
Gymnotidae Gymnotus curupira Crampton, Thorsen & Albert, 2005 Fr native    23.50 cm TL male/unsexed  Known from terra firme forest swamps and stream pools of the Rio Tefé drainage near the town of Tefé, Amazonas (Ref. 55508). - 
Gymnotidae Gymnotus darwini Campos-da-Paz & de Santana, 2019 Fr native   15.70 cm TL male/unsexed  Type locality of the holotype of Gymnotus darwini: Rio Botafogo basin, at Refugio Ecol´ogico Charles Darwin, Igarassu (Ref. 128926). - 
Gymnotidae Gymnotus diamantinensis Campos-da-Paz, 2002 Fr native   12.50 cm TL male/unsexed  Known only from its type locality, a creek tributary of the rio Preto at the upper portion of the rio Arinos system (Tapajós river basin, Mato Grosso State) (Ref. 42925). - 
Gymnotidae Gymnotus inaequilabiatus (Valenciennes, 1839) Fr native    99.80 cm TL male/unsexed 19.3 TL Not in Ref. 36692. + 
Gymnotidae Gymnotus interruptus Rangel-Pereira, 2012 Fr native   12.11 cm TL male/unsexed  Found in the Riacho Cambiriba, an affluent of the rio Gongogi, Guaíra Balneary, Iguaí in Bahia (Ref. 93136) - 
Gymnotidae Gymnotus javari Albert, Crampton & Hagedorn, 2003 Fr native  Sarapó (Portuguese)   20.10 cm TL male/unsexed  Found in the Purus and Acre River basins (Ref. 97592). - 
Gymnotidae Gymnotus jonasi Albert & Crampton, 2001 Fr native   13.50 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36692). Type locality: Amazonas: Cano do Lago Rato, Mamirauá Reserve. - 
Gymnotidae Gymnotus mamiraua Albert & Crampton, 2001 Fr native   24.30 cm TL male/unsexed  Known from two whitewater lake systems on the Rio Solimões floodplain of central Amazonia (the Mamirauá lake system near Tefé, and Lago Janauacá near Manaus), Amazonas State, Brazil (Ref. 41292). - 
Gymnotidae Gymnotus melanopleura Albert & Crampton, 2001 Fr native   10.00 cm TL male/unsexed  Found in the upper Amazon River basin (Ref. 36692). - 
Gymnotidae Gymnotus obscurus Crampton, Thorsen & Albert, 2005 Fr native   21.50 cm TL male/unsexed  Known only from the varzea floodplain at the conflluence of the Rio Solimoes (Amazon) and the Rio Japura in Mamiraua Reserve near the Tefé, Amazonas (Ref. 55508). - 
Gymnotidae Gymnotus onca Albert & Crampton, 2001 Fr native   12.00 cm TL male/unsexed  Found in the upper Amazon River basin (Ref. 36692). Type locality: Cano do Lago Rato, Mamirauá Reserve, 3°02'36"S, 64°51'02"W, Amazonas, Brazil (Ref. 41292). - 
Gymnotidae Gymnotus pantanal Fernandes, Albert, Daniel-Silva, Lopes, Crampton & Almeida-Toledo, 2005 Fr native    26.00 cm TL male/unsexed  Found in Pantanal Matogrossense (Ref. 54472). + 
Gymnotidae Gymnotus pantherinus (Steindachner, 1908) Fr native    23.58 cm TL male/unsexed    + 
Gymnotidae Gymnotus paraguensis Albert & Crampton, 2003 Fr native  Tuvira (Portuguese)   24.00 cm SL male/unsexed  Recorded from Rio Nueva, Mato Grosso do Sul (Ref. 49716). + 
Gymnotidae Gymnotus pedanopterus Mago-Leccia, 1994 Fr native  Sarrapu (Portuguese)   28.10 cm TL male/unsexed  Found in tributaries of the Rio Negro (Ref. 36692). + 
Gymnotidae Gymnotus refugio Giora & Malabarba, 2016 Fr native    Type locality from holotype Gymnotus refugio, Amaral Ferrador, creek in the former Ferraria farm, laguna dos Patos drainage, Rio Grande do Sul (Ref. 128476). - 
Gymnotidae Gymnotus sylvius Albert & Fernandes-Matioli, 1999 Fr native    42.00 cm SL male/unsexed  Found in Ribeira de Iguape, Paraíba do Sul, and Pardo River basins (Ref. 36692). + 
Gymnotidae Gymnotus tigre Albert & Crampton, 2003 Fr native   41.10 cm TL male/unsexed   + 
Gymnotidae Gymnotus tiquie Maxime, Lima & Albert, 2011 Fr native  Wapu-dike (Tucano)  24.00 cm TL male/unsexed  Type locality, Amazonas, Rio Tiquié, a tributary of the Uaupés (Vaupés) in the upper Negro basin (Ref. 83328). + 
Gymnotidae Gymnotus varzea Crampton, Thorsen & Albert, 2005 Fr native   28.50 cm TL male/unsexed  Known from varzea floodplains at the confluence of the Rio Solimoes (Amazon) and Rio Japura in the Miraua Reserve near Tefe, Amazonas (Ref. 55508). - 
Trichomycteridae Haemomaster venezuelae Myers, 1927 Fr native   6.60 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39970). + 
Loricariidae Harttia absaberi Oyakawa, Fichberg & Langeani, 2013 Fr native   7.41 cm SL male/unsexed  Known from the three localities in the upper rio Paraná drainage: rio Passa Cinco, a tributary of the rio Piracicaba, rio Tietê drainage, São Paulo State, and two small creeks tributaries of the rio Sucuriú, at Três Lagoas, Mato Grosso do Sul State (Ref. 94714). - 
Loricariidae Harttia carvalhoi Miranda Ribeiro, 1939 Fr native    7.10 cm SL male/unsexed  Known from the Paquequer River basin in Paraíba do Sul River drainage (Ref. 36389). + 
Loricariidae Harttia depressa Rapp Py-Daniel & Oliveira, 2001 Fr endemic   12.60 cm SL male/unsexed  Known from the Uatumã River basin (Ref. 36389). - 
Loricariidae Harttia dissidens Rapp Py-Daniel & Oliveira, 2001 Fr endemic   15.20 cm SL male/unsexed  Occurs in the lowermost small cataracts of rio Tapajós and close to the mouth of the Jamanxim River (Ref. 39753). Also Ref. 36389. - 
Loricariidae Harttia duriventris Rapp Py-Daniel & Oliveira, 2001 Fr endemic   12.80 cm SL male/unsexed  Found in the Tocantins River (Ref. 36389). Only collected from the rapids above Tucurui, in the area now flooded by the dam (Ref. 40703). Also Ref. 36389. - 
Loricariidae Harttia fowleri (Pellegrin, 1908) Fr native  Acari (Portuguese), Cachimbo (Portuguese)  22.16 cm SL male/unsexed  Known from the Oyapock River River (36389). + 
Loricariidae Harttia garavelloi Oyakawa, 1993 Fr native   8.60 cm SL male/unsexed  Found in the Fanado and Araçuaí rivers (Ref. 36389). + 
Loricariidae Harttia gracilis Oyakawa, 1993 Fr native    10.10 cm SL male/unsexed  Known from the São João and upper Paraná River basins (Ref. 36389). Regarded as threatened in the state of Minas Gerais (Ref. 26603). + 
Loricariidae Harttia kronei Miranda Ribeiro, 1908 Fr native  Cascudo-chato (Portuguese), Krone's flat suckermouth catfish (English), Bituva (Portuguese)  12.00 cm SL male/unsexed  Known from the Ribeira de Iguape River basin (Ref. 36389). Occurs in Betari River basin, Southeastern Brazil (Ref. 38979). + 
Loricariidae Harttia leiopleura Oyakawa, 1993 Fr native  Cari (Portuguese)  5.70 cm SL male/unsexed  Found in Das Velhas River basin (Ref. 36389). Regarded as threatened in the state of Minas Gerais (Ref. 26603). + 
Loricariidae Harttia longipinna Langeani, Oyakawa & Montoya-Burgos, 2001 Fr native  Cascudo (Portuguese)  10.70 cm SL male/unsexed  Known from the upper São Francisco River basin (Ref. 36389). - 
Loricariidae Harttia loricariformis Steindachner, 1877 Fr native    18.60 cm SL male/unsexed  Found in the Paraíba do Sul River basin (Ref. 36389). - 
Loricariidae Harttia novalimensis Oyakawa, 1993 Fr native   5.80 cm SL male/unsexed  Found in Das Velhas River basin (Ref. 36389). Regarded as threatened in the state of Minas Gerais (Ref. 26603). + 
Loricariidae Harttia panara Oyakawa, Fichberg & Rapp Py-Daniel, 2018 Fr native   10.57 cm SL male/unsexed  Type locality of Harttia panara, Rio Xingu Basin, Rio Curuá, tributary of Rio Iriri, above the Cachoeira do Curuá waterfall (Ref. 117418). - 
Loricariidae Harttia punctata Rapp Py-Daniel & Oliveira, 2001 Fr native   16.60 cm SL male/unsexed ;14.00 cm SL female  Known from the upper and middle courses of Tocantins River. Specimens collected from Pará, below Tucurui dam and Goiás, Xambioá, rio Araguaia; rio Passa Três; rio Tocantins drainage, Serra da Mesa (Ref. 39753). Also Ref. 36389. - 
Loricariidae Harttia rhombocephala Miranda Ribeiro, 1939 Fr native  Cascudo (Portuguese)    Known from the Farias River basin (Ref. 36389). - 
Loricariidae Harttia rondoni Oyakawa, Fichberg & Rapp Py-Daniel, 2018 Fr native   16.28 cm SL male/unsexed  Type locality of Harttia rondoni, Rio Curuá, tributary of Rio Iriri, near Castelo dos Sonhos, Rio Xingu drainage, Para State (Ref. 117418). - 
Loricariidae Harttia torrenticola Oyakawa, 1993 Fr native  Cascudo (Portuguese)  7.70 cm SL male/unsexed  Known from the São Francisco River basin (Ref. 36389). + 
Loricariidae Harttia trombetensis Rapp Py-Daniel & Oliveira, 2001 Fr native   17.60 cm SL male/unsexed  Found in the Trombetas River basin, above Cachoeira Porteira falls (Ref. 36389). - 
Loricariidae Harttia uatumensis Rapp Py-Daniel & Oliveira, 2001 Fr native   11.90 cm SL male/unsexed  Known from rio Uatumã and in at least 2 of its affluents, rio Pitinga (upper Uatumã) and rio Jatapu (lower Uatumã) (Ref. 39753). Also Ref. 36389. - 
Loricariidae Harttia villasboas Oyakawa, Fichberg & Rapp Py-Daniel, 2018 Fr native   12.60 cm SL male/unsexed  Type locality Harttia villasboas, Serra do Cachimbo, Rio Xingu basin, Pará (Ref. 117418). - 
Characidae Hasemania crenuchoides Zarske & Géry, 1999 Fr native   6.72 cm SL male/unsexed   - 
Characidae Hasemania hanseni (Fowler, 1949) Fr native    3.30 cm SL male/unsexed  Also Ref. 598. + 
Characidae Hasemania kalunga Bertaco & Carvalho, 2010 Fr native   5.33 cm SL male/unsexed  Found in the upper rio Tocantins basin, tributary of rio das Almas, Cavalcante, Goiás State (Ref. 83954). - 
Characidae Hasemania maxillaris Ellis, 1911 Fr native  Lambari (Portuguese)   2.90 cm TL male/unsexed  Known from the Iguaçu River basin (Ref. 38376). Also Ref. 598. - 
Characidae Hasemania melanura Ellis, 1911 Fr native  Lambari (Portuguese)   4.40 cm TL male/unsexed  Found in the Iguaçu River basin (Ref. 38376). Also Ref. 598. - 
Characidae Hasemania nambiquara Bertaco & Malabarba, 2007 Fr native   2.70 cm SL male/unsexed  Occurs only in the upper Rio Tapajós drainage in Mato Grosso (Ref. 75743). + 
Characidae Hasemania nana (Lütken, 1875) Fr native  Piaba (Portuguese), Piabinha vermelha (Portuguese)  2.66 cm SL male/unsexed  Also Ref. 598. + 
Characidae Hasemania piatan Zanata & Serra, 2010 Fr native   5.40 cm SL male/unsexed  Found in streams riacho Três Morros and córrego das Piabas, small tributaries of upper rio de Contas drainage in Piatã, Bahia, northeastern Brazil (Ref. 83965). + 
Characidae Hasemania uberaba Serra & Langeani, 2015 Fr native   7.00 cm SL male/unsexed  Known from the headwaters of the rio Uberaba, rio Grande basin, upper rio Paraná basin, Minas Gerais (Ref. 104709). Status of threat: can be considered as Data Deficient (DD) until more information about its biology and geographical distribution is available. - 
Doradidae Hassar affinis (Steindachner, 1881) Fr native  Mandí pirá (Portuguese), Bagre (Portuguese), Bicudo (Portuguese), Cabeça de burro (Portuguese), Mandi bicudo (Portuguese), Mandí bicudo (Portuguese), Mandi cachorro (Portuguese), Mandí cachorro (Portuguese), Mandi pirá (Portuguese)   20.70 cm SL male/unsexed  Known from Parnaíba River basin. Questionable records fom Río Itapicuru and Fortaleza (Ref. 37054). - 
Doradidae Hassar gabiru Birindelli, Fayal & Wosiacki, 2011 Fr native   28.50 cm TL male/unsexed  Type locality, Rio Curuá, Iriri drainage, at Vila Castelo dos Sonhos, Altamira, PA, MZUSP 108440 (holotype of Hassar gabiru, 13.04 cm SL). Known from the middle to upper Xingu river basin, and is apparently endemic to the Xingu basin above the raids of Volta Grande, near Altamira (Ref. 87857). - 
Doradidae Hassar orestis (Steindachner, 1875) Fr native  Botinho (Portuguese)   29.80 cm TL male/unsexed  Known from the Rio Xingu (Ref. 6868). + 
Doradidae Hassar shewellkeimi Sabaj Pérez & Birindelli, 2013 Fr native   22.09 cm SL male/unsexed  Found in the rio Teles Pires and one or more sites in the upper rio Juruena (likely above mouth of rio Arinos), two large river systems draining northwestern portions of Shield uplands. + 
Doradidae Hassar wilderi Kindle, 1895 Fr native  Botinho (Portuguese), Mandí boca de flor (Portuguese), Mandí sacaca (Portuguese), Mandí serra (Portuguese)   25.00 cm TL male/unsexed  Known from Rio Tocantins in Troceros and Touceira (Ref. 6868). + 
Potamotrygonidae Heliotrygon gomesi Carvalho & Lovejoy, 2011 Fr native  Gomes’s round ray (English)  13.50 cm WD male/unsexed  Found in the upper Rio Amazonas basin according to the material studied, but suspected to enter the lower reaches of most major tributaries and the lower Rio Amazonas basin as well (Ref. 86515). - 
Potamotrygonidae Heliotrygon rosai Carvalho & Lovejoy, 2011 Fr native  Rosa’s round ray (English)  80.00 cm WD male/unsexed  Occurs in the upper, mid and lower Rio Amazonas basin, and probably also enters the lower reaches of its major tributaries (Ref. 86515). - 
Cetopsidae Helogenes gouldingi Vari & Ortega, 1986 Fr endemic   4.70 cm SL male/unsexed  Collected from Igarapé 15 km from Humaitá along the Rio Madeira, Amazonas (Ref. 7462). Found in Machado River basin (Ref. 97589). - 
Cetopsidae Helogenes marmoratus Günther, 1863 Fr native  Asicurrupa (Portuguese)   7.90 cm SL male/unsexed  Found in the Amazon basin. + 
Loricariidae Hemiancistrus cerrado de Souza, Melo, Chamon & Armbruster, 2008 Fr native   17.04 cm SL male/unsexed  Found in rio do Bugre, rio Vermelho and probably rio do Peixe, tributaries of rio Araguiaia, rio Tocantins basin in Goiás State (Ref. 79076). - 
Loricariidae Hemiancistrus chlorostictus Cardoso & Malabarba, 1999 Fr, Sp native  Cascudo (Portuguese)   14.70 cm SL male/unsexed  Known from the upper Uruguay River basin, Passo Fundo dam (Ref. 36713). - 
Loricariidae Hemiancistrus fuliginosus Cardoso & Malabarba, 1999 Fr native  Cascudo (Portuguese)   16.20 cm SL male/unsexed  Known from the Uruguay River basin (Ref. 36713). + 
Loricariidae Hemiancistrus megalopteryx Cardoso, 2004 Fr native   28.64 cm SL male/unsexed  Found in Rio Tubarão drainage, Santa Catarina (Ref. 52458). - 
Loricariidae Hemiancistrus meizospilos Cardoso & da Silva, 2004 Fr native   14.91 cm SL male/unsexed  Known only from the rio Chapeco system, tributary of the rio Uruguai (upper rio Uruguai basin) in Santa Catarina (Ref. 54753). + 
Loricariidae Hemiancistrus punctulatus Cardoso & Malabarba, 1999 Fr native  Cascudo (Portuguese)   19.00 cm SL male/unsexed  Known from the Laguna dos Patos basin (Ref. 36713). + 
Loricariidae Hemiancistrus votouro Cardoso & da Silva, 2004 Fr native   14.12 cm SL male/unsexed  Found only in the arroio Lageado Grande, tributary of the rio Erechim, rio Passo Fundo system of the upper rio Uruguai basin in Rio Grande do Sul (Ref. 54753). - 
Characidae Hemibrycon jelskii (Steindachner, 1876) Fr native   7.79 cm SL male/unsexed ;10.17 cm SL female   - 
Characidae Hemibrycon surinamensis Géry, 1962 Fr native   9.50 cm SL male/unsexed  Known from lower rios Tapajós, Tocantins and Xigu basins, Pará (Ref. 85819). + 
Doradidae Hemidoras boulengeri Steindachner, 1915 Fr native    19.30 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). - 
Doradidae Hemidoras morei (Steindachner, 1881) Fr native  Cuyu cuyu (Portuguese)  16.30 cm SL male/unsexed  Known from Negro River basin (Ref. 37054). + 
Doradidae Hemidoras morrisi Eigenmann, 1925 Fr native    14.40 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Doradidae Hemidoras stenopeltis (Kner, 1855) Fr native    19.40 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Doradidae Hemidoras stuebelii (Steindachner, 1882) Fr native  Shitari (Portuguese)  15.20 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Characidae Hemigrammus analis Durbin, 1909 Fr native    3.90 cm TL male/unsexed    - 
Characidae Hemigrammus arua Lima, Wosiacki & Ramos, 2009 Fr native   3.00 cm SL male/unsexed  Found in the headwaters of the rio Arapiuns (rio Branco and rio Aruã), rio Tapajós basin, and from the adjacent headwaters of the igarapé Juruti Grande, a right margin tributary of the rio Amazonas in Pará State (Ref. 81198). + 
Characidae Hemigrammus ataktos Marinho, Dagosta & Birindelli, 2014 Fr native   3.77 cm SL male/unsexed  Known from the middle rio Tocantins basin, from rio Santa Tereza, Goiás State, from the rio Manoel Alves basin, and from smaller tributaries of the rio Tocantins immediately downstream of the mouth of rio Manoel Alves, Tocantins State (Ref. 96858). - 
Characidae Hemigrammus bellottii (Steindachner, 1882) Fr native    3.25 cm SL male/unsexed  Found in the Machado (Ref. 97589) and Acre River basins (Ref. 97592). Also Ref. 12225. + 
Characidae Hemigrammus brevis Ellis, 1911 Fr native  Lambari (Portuguese), Piaba (Portuguese)   3.60 cm TL male/unsexed  Also Ref. 598. + 
Characidae Hemigrammus coeruleus Durbin, 1908 Fr native    5.80 cm TL male/unsexed  Type locality, Manacapuru (Ref. 38376). Also Ref. 598. + 
Characidae Hemigrammus cupreus Durbin, 1918 Fr native   5.30 cm TL male/unsexed  Also Ref. 598. - 
Characidae Hemigrammus diagonicus Mendonça & Wosiacki, 2011 Fr native   2.80 cm SL male/unsexed  Type locality, State of Pará, Lago do Piranha, Juruti, Lower Amazon, MPEG 10321 (holotype of Hemigrammus diagonicus, 2.8 cm SL). Known only from the Balaio and Piranha lakes of the lower Amazon River, Juruti, State of Pará (Ref. 87304). - 
Characidae Hemigrammus durbinae Ota, Lima & Pavanelli, 2015 Fr native   2.80 cm SL male/unsexed  Known from central and western portions of the Amazon basins, at the middle and upper portions of the rio Madeira, lower rio Purus, middle rio Solimões/Amazonas, and lower rio Tapajós; and rio Paraguai basin (Ref. 101340). - 
Characidae Hemigrammus elegans (Steindachner, 1882) Fr native   4.00 cm SL male/unsexed  Also Ref. 598. - 
Characidae Hemigrammus filamentosus Zarske, 2011 Fr native   3.61 cm SL male/unsexed  Known from the rio Araguaya basin (Ref. 87321). + 
Characidae Hemigrammus geisleri Zarske & Géry, 2007 Fr native   3.50 cm TL male/unsexed  Known from central Amazon (Ref. 58756). + 
Characidae Hemigrammus gracilis (Lütken, 1875) Fr native  Piaba (Portuguese), Piaba da lagoa santa (Portuguese), Piabinha branca (Portuguese)   4.40 cm SL male/unsexed  Also Ref. 598. + 
Characidae Hemigrammus haraldi Géry, 1961 Fr native    2.73 cm SL male/unsexed    - 
Characidae Hemigrammus hyanuary Durbin, 1918 Fr native  Neon verde (Portuguese)   4.40 cm TL male/unsexed  Also Ref. 598. + 
Characidae Hemigrammus iota Durbin, 1909 Fr native    2.10 cm TL male/unsexed   - 
Characidae Hemigrammus levis Durbin, 1908 Fr native  common (usually seen) 5.90 cm TL male/unsexed  Also Ref. 598. + 
Characidae Hemigrammus lunatus Durbin, 1918 Fr native    4.80 cm TL male/unsexed  Known from the Amazon, Paraguay (Ref. 96864) and Acre River basins (Ref. 97592). Also Ref. 598. - 
Characidae Hemigrammus machadoi Ota, Lima & Pavanelli, 2014 Fr native   3.58 cm SL male/unsexed 2.54 Found in the upper rio Paraguai basin, from the rio Guaporé and some other smaller tributaries of the rio Mamoré and rio Madeira, on the upper and middle portions of the rio Madeira basin (Ref. 96864). - 
Characidae Hemigrammus marginatus Ellis, 1911 Fr native  Bandeirinha de rabo amarelo (Portuguese), Bandeirinha de rabo vermelho (Portuguese), Lambari (Portuguese), Piaba (Portuguese) common (usually seen) 4.50 cm SL male/unsexed 1.8 TL Recorded from Caracu and Sao Pedro streams, tributaries of the Paraná river (Ref. 26076). Rather common in certain places (Ref. 598). Also Ref. 38376. + 
Characidae Hemigrammus melanochrous Fowler, 1913 Fr native    3.00 cm TL male/unsexed  Reported from Machado river basin (Ref. 97589). Also Ref. 598. - 
Characidae Hemigrammus microstomus Durbin, 1918 Fr native   4.00 cm SL male/unsexed  Found in the Amazon River basin (Ref. 38376). Also Ref. 598. - 
Characidae Hemigrammus mimus Böhlke, 1955 Fr native   2.83 cm SL male/unsexed  Also Ref. 598. - 
Characidae Hemigrammus neptunus Zarske & Géry, 2002 Fr native    3.20 cm SL male/unsexed  Reported from Machado river basin (Ref. 97589). + 
Characidae Hemigrammus newboldi (Fernández-Yépez, 1949) Fr native    5.00 cm SL male/unsexed   + 
Characidae Hemigrammus ocellifer (Steindachner, 1882) Fr native  Lambari azul (Portuguese), Olho de fogo (Portuguese)   4.90 cm TL male/unsexed  Found in the Amazon (Ref. 38376) and Acre River basins (Ref. 97592). + 
Characidae Hemigrammus orthus Durbin, 1909 Fr native   3.40 cm TL male/unsexed  Lower Tapajós River. - 
Characidae Hemigrammus parana Marinho, Carvalho, Langeani & Tatsumi, 2008 Fr native    3.08 cm SL male/unsexed  Found only in the area of influence of the Ilha Solteira reservoir, upper Paraná system, southeastern Brazil, throughout margins of rio Grande, rio Paraná, rio Paranaíba and rio São José dos Dourados(Ref. 74938). - 
Characidae Hemigrammus pretoensis Géry, 1965 Fr native   5.08 cm SL male/unsexed  Found in the upper Solimões River basin (Ref. 38376). Also Ref. 598, 96859. + 
Characidae Hemigrammus rodwayi Durbin, 1909 Fr native    5.30 cm TL male/unsexed  Also Ref. 598. + 
Characidae Hemigrammus schmardae (Steindachner, 1882) Fr native   5.40 cm TL male/unsexed  Found in the Amazon and Negro River basins (Ref. 38376). + 
Characidae Hemigrammus silimoni Britski & Lima, 2008 Fr native   3.29 cm SL male/unsexed  Recorded only from a type locality on the upper Rio Juruena, a tributary of the Rio Tapajós in Mato Grosso (Ref. 78749). - 
Characidae Hemigrammus skolioplatus Bertaco & Carvalho, 2005 Fr native    Known from the upper río Tapajós drainage (Ref. 57598). - 
Characidae Hemigrammus stictus (Durbin, 1909) Fr native    4.30 cm TL male/unsexed  Collected from Pará State (rio Araticum and rio Paru) and Amazonas State ( rio Negro and rio Amazonas) (Ref. 81198). Also Ref. 38376. + 
Characidae Hemigrammus tocantinsi Carvalho, Bertaco & Jerep, 2010 Fr native   3.68 cm SL male/unsexed  Type locality, Goiás, Cavalcante, rio das Pedras, Fazenda Córrego Fundo, MCP 44444 (holotype of Hemigrammus tocantinsi, 2.82 cm SL, male) (Ref. 84464). - 
Characidae Hemigrammus tridens Eigenmann, 1907 Fr native   2.00 cm SL male/unsexed  Found in Pantanal (Ref. 81048). + 
Characidae Hemigrammus ulreyi (Boulenger, 1895) Fr native   4.40 cm TL male/unsexed   + 
Characidae Hemigrammus unilineatus (Gill, 1858) Fr native  Lambari pipira (Portuguese), Piaba (Portuguese)   5.30 cm TL male/unsexed  Occurs in the Amazon basin (Ref. 12225). Also Ref. 38376. + 
Characidae Hemigrammus vorderwinkleri Géry, 1963 Fr native    3.30 cm SL male/unsexed  Also Ref. 598. - 
Characidae Hemigrammus yinyang Lima & Sousa, 2009 Fr native   2.92 cm SL male/unsexed  Known only from tributaries of the middle rio Tiquie, a tributary of the rio Uaupes, upper rio Negro basin in Amazonas state (Ref. 82434). - 
Loricariidae Hemiodontichthys acipenserinus (Kner, 1853) Fr native  Cascudo (Portuguese)   13.40 cm SL male/unsexed  Found in the Acre River basin (Ref. 97592). + 
Hemiodontidae Hemiodus amazonum (Humboldt, 1821) Fr native    20.50 cm SL male/unsexed   - 
Hemiodontidae Hemiodus argenteus Pellegrin, 1909 Fr, Fi native  Jatuarana (Portuguese), Charuto (Portuguese), Flexeira (Portuguese), Oma (Portuguese), Orana (Portuguese), Orna (Portuguese), Voador (Portuguese), Voador escama fina (Portuguese)   23.70 cm SL male/unsexed  Also Ref. 38289. + 
Hemiodontidae Hemiodus atranalis (Fowler, 1940) Fr native  Cruzeiro-do-sul (Portuguese)   20.00 cm SL male/unsexed    + 
Hemiodontidae Hemiodus goeldii Steindachner, 1908 Fr native   16.00 cm SL male/unsexed  Known from the Amapá River basin (Ref. 38289). Also Ref. 35366. - 
Hemiodontidae Hemiodus gracilis Günther, 1864 Fr native  Cruzeiro-do-sul (Portuguese), Charuto (Portuguese), Flexeiro (Portuguese)   16.30 cm SL male/unsexed  Known from Negro, Tapajós, Madeira, Solimões, Amazon River basins (Ref. 38289). Also Ref. 2037. + 
Hemiodontidae Hemiodus immaculatus Kner, 1858 Fr, Fi native  Jatuarana (Portuguese), Charuto (Portuguese), Flexeira (Portuguese), Orana (Portuguese), Voador (Portuguese)   24.70 cm SL male/unsexed  Type locality: Barra do Rio Negro, Brazil. Also Ref. 598, 38289. + 
Hemiodontidae Hemiodus iratapuru Langeani & Moreira, 2013 Fr native   13.40 cm SL male/unsexed  Known from the Rio Jari and its tributary, Rio Iratapuru, upstream of the Cachoeira de Santo Antonio (Ref. 93237). - 
Hemiodontidae Hemiodus jatuarana Langeani, 2004 Fr native    Known from Rio Trombetas, Amazon basin (Ref. 53268). - 
Hemiodontidae Hemiodus langeanii Beltrão & Zuanon, 2012 Fr native  Orana (Portuguese), Charuto (Portuguese), Cubio (Portuguese), Flecheiro (Portuguese)  13.56 cm SL male/unsexed  Known of the type locality in the rio Amana, rio Maués-Açu drainage, near the boundary of the States of Pará and Amazonas (Ref. 91067). - 
Hemiodontidae Hemiodus microlepis Kner, 1858 Fr, Fi native  Jatuarana (Portuguese), Bananinha (Portuguese), Charuto (Portuguese), Flexeira (Portuguese), Orana (Portuguese), Piava-banana (Portuguese)   23.90 cm SL male/unsexed  Known from Madeira and Tocantins River basins (Ref. 38289). Also Ref. 598, 12202. + 
Hemiodontidae Hemiodus orthonops Eigenmann & Kennedy, 1903 Fr native  Bananinha (Portuguese), Peixe-banana (Portuguese), Piau-banana (Portuguese), Piava-banana (Portuguese), Tainha (Portuguese)   31.00 cm TL male/unsexed ;34.20 cm TL female    + 
Hemiodontidae Hemiodus parnaguae Eigenmann & Henn, 1916 Fr native  Avoador (Portuguese), Doirado (Portuguese), Voador (Portuguese)   14.60 cm SL male/unsexed  Known from the Parnaíba River basin(Ref. 38289). Recorded from the Rio Parnagua (Ref. 598). + 
Hemiodontidae Hemiodus quadrimaculatus Pellegrin, 1909 Fr native   13.10 cm SL male/unsexed  Present in the Amazon basin (Ref. 598) and the Oyapock River which forms the border between French Guiana and Brazil (Ref. 12225). + 
Hemiodontidae Hemiodus semitaeniatus Kner, 1858 Fr native  Bananinha (Portuguese), Falso cruzeiro do sul (Portuguese), Peixe-banana (Portuguese), Piau-banana (Portuguese)   20.00 cm SL male/unsexed  Type locality: Rio Guapore, Amazon system, Brazil (Ref. 33021). + 
Hemiodontidae Hemiodus sterni (Géry, 1964) Fr native   7.90 cm SL male/unsexed  Known from the upper Juruena River basin in Tapajós River drainage (Ref. 38289). Also Ref. 598. - 
Hemiodontidae Hemiodus ternetzi Myers, 1927 Fr native    21.50 cm SL male/unsexed ;25.20 cm female  Recorded from the Rio Tocantins (Ref. 598, 38289). + 
Hemiodontidae Hemiodus thayeria Böhlke, 1955 Fr native   8.90 cm SL male/unsexed  Recorded from the Solimões and Negro River basins (Ref. 38289). Also Ref. 38289. - 
Hemiodontidae Hemiodus tocantinensis Langeani, 1999 Fr native   16.00 cm SL male/unsexed  Known from Rio Araguaia and Rio Tocantins (Ref. 31397). Also Ref. 38289. - 
Hemiodontidae Hemiodus unimaculatus (Bloch, 1794) Fr, Fi native  Jatuarana (Portuguese), Charuto (Portuguese), Orana (Portuguese), Pacu-banana (Portuguese), Palito (Portuguese), Peixe-rei (Portuguese), Ubari (Portuguese), Uiarana (Portuguese), Voador (Portuguese), Voador escama fina (Portuguese)   32.90 cm SL male/unsexed ;29.40 cm SL female  Reported from Machado (Ref. 97589) and Guapore river basin, Rondônia State and Orinoco river, Para State. Found in fish markets in Santarém (Ref. 12202). + 
Hemiodontidae Hemiodus vorderwinkleri (Géry, 1964) Fr native   16.50 cm SL male/unsexed   + 
Loricariidae Hemipsilichthys gobio (Lütken, 1874) Fr native  Anhã (Portuguese), Cascudinho (Portuguese), Cascudo (Portuguese), Cascudo barbado (Portuguese), Cascudo espinho (Portuguese), Cascudo pardo (Portuguese), Cascudo piririca (Portuguese), Couraçado (Portuguese), Mãe de anhã (Portuguese)  15.64 cm SL male/unsexed  Known from the rio Paraiba do Sul basin in Sao Paulo, Rio de Janeiro and Minas Gerais (Ref. 42856). Museum: type locality not explicitly given, restricted to Paraíba do Sul River basin, ZMUC 76 (holotype of Xenomystus gobio Lütken, 1874) (Ref. 26282). Museum: Rio Paquequer ad Theresópolis, Rio de Janeiro, MNRJ 639 (holotype of Upsilodus victori Miranda Ribeiro, 1924) (Ref. 6868, 26282). Also Ref. 36817. - 
Loricariidae Hemipsilichthys nimius Pereira, Reis, Souza & Lazzarotto, 2003 Fr native   10.51 cm SL male/unsexed  Recorded from the state of Rio de Janeiro ( Perequê-Açu and Taquari river basins) (Ref. 50588). Type locality: Rio de Janeiro: Parati: rio Carrasquinho below the Cachoeira do Tobogã, upper Perequê-Açu basin, Penha, ca. 7.5 km west of highway BR 101, on road from Parati to Cunha (Ref. 50588). - 
Loricariidae Hemipsilichthys papillatus Pereira, Oliveira & Oyakawa, 2000 Fr native   9.18 cm SL male/unsexed  Known from the tributary of the rio Preto, rio Paraiba do Sul basin in Minas Gerais (Ref. 42856). Also Ref. 36817, 45132. - 
Pimelodidae Hemisorubim platyrhynchos (Valenciennes, 1840) Fr, Fi native  Bico de pato (Portuguese), Boca de colher (Portuguese), Braço de moça (Portuguese), Giripóca (Portuguese), Jerepoca (Portuguese), Jeripoca (Portuguese), Jerupoca (Portuguese), Jurupensén (Portuguese), Jurupoca (Portuguese), Liro (Portuguese), Mandi açu (Portuguese), Mandubé (Portuguese), Mandubé pintadinho (Portuguese)   61.00 cm TL female 24 TL Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). Found in fish markets in Santarém (Ref. 12202). Also Ref. 36506. + 
Bryconidae Henochilus wheatlandii Garman, 1890 Fr endemic  Andirá (Portuguese), Anjirá (Portuguese)   41.30 cm SL male/unsexed  Known from Mucuri and Doce River basins (Ref. 38504). Reported to occur only in the rio Santo Antônio basin, which has a total drainage area of 10,390 sq. km. However, since the species appears not to occur in the entire basin, its actual distribution area is substantially smaller. Using the IUCN (1996) criteria, status should be listed as endangered because is has a small distribution, known to exist in less than 5 locations, and its occurrence declining, area of occupancy and quality of habitat. Proposed to change its indeterminate status to endangered "EN B1+2abc" (Ref. 40429). Also Ref. 598. + 
Trichomycteridae Henonemus intermedius (Eigenmann & Eigenmann, 1889) Fr native   8.00 cm NG male/unsexed  Known from the Araguaia River basin (Ref. 39970). Type locality: Goias, Brazil (Ref. 26282, 6868). - 
Trichomycteridae Henonemus macrops (Steindachner, 1882) Fr native   6.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39970). Type locality: Lake Manacapuru (Ref. 26282, 6868). - 
Trichomycteridae Henonemus punctatus (Boulenger, 1887) Fr native    9.00 cm NG male/unsexed  Known from the Amazon River basin (Ref. 39970). + 
Heptapteridae Heptapterus carmelitanorum Deprá, Aguilera, Faustino-Fuster, Katz & Azevedo-Santos, 2022 Fr native  Carmelitano catfish (English)  14.43 cm SL male/unsexed  Type locality of Heptapterus carmelitanorum, Minas Gerais State: limit of Carmo do Rio Claro and Ilicínea municipalities, uknown named stream tributary of Itací stream, tributary of Sapucaí River (stretch flooded by Furnas reservoir), Grande River Drainage, Paraná River basin, 830 m asl. Recorded only from a single unnamed stream and the watercourse is a tributary of Itací stream - ribeirão Itací, in Portuguese – which is an affluent of Furnas reservoir (in the Sapucaí River arm), Grande River basin, in the upper Paraná River system, in Minas Gerais State (Ref. 127242). - 
Heptapteridae Heptapterus longicauda (Borodin, 1927) Fr endemic  Bagre (Portuguese), Mandi (Portuguese), Mané-comprido (Portuguese)   15.70 cm SL male/unsexed  Type locality of Imparfinis borodini- 
Heptapteridae Heptapterus multiradiatus Ihering, 1907 Fr endemic    9.60 cm SL male/unsexed  Found in Alto da Serra, São Paulo (Ref. 6868). Known from the upper Tietê River basin (Ref. 36914). - 
Heptapteridae Heptapterus mustelinus (Valenciennes, 1835) Fr native  Bagre (Portuguese), Bagre-de-pedra (Portuguese), Mandizinho (Portuguese)   26.00 cm SL male/unsexed  Occurs in the Uruguay River basin and coastal drainages of South Brazil (Ref. 36914). + 
Heptapteridae Heptapterus ornaticeps Ahl, 1936 Fr native   6.80 cm SL male/unsexed  Known from the Rio de Janeiro. Also Ref. 36914. - 
Heptapteridae Heptapterus stewarti Haseman, 1911 Fr endemic  Bagre da pedra (Portuguese), Chicote (Portuguese), Cobrissa (Portuguese)  13.90 cm SL male/unsexed  Found in Serrinha Parana (Ref. 6868). Known from the Iguaçu River basin (Ref. 36914). - 
Heptapteridae Heptapterus sympterygium Buckup, 1988 Fr endemic   4.70 cm SL male/unsexed  Found in the coastal lowalnds of eastern Rio Grande do Sul (Ref. 36914). Museum: Mirim, MZUSP 19179 (Ref. 46206). Also Ref. 6868. - 
Cichlidae Heros efasciatus Heckel, 1840 Fr native  Acará-peba (Portuguese), Acara piranga (Portuguese), Acará-preto (Portuguese)   17.00 cm SL male/unsexed  Known from the tributaries of the Solimões-Amazon River (Ref. 36377). + 
Cichlidae Heros notatus (Jardine, 1843) Fr endemic   15.00 cm SL male/unsexed  Type locality of Heros notatus, Essequibo river. Known from the Negro River basin of the Amazon River basin (Ref. 36377). + 
Cichlidae Heros severus Heckel, 1840 Fr native  Acará-peba (Portuguese), Acará-piranga (Portuguese), Acará-preto (Portuguese), Cará caroço de manga (Portuguese), Cará de lago (Portuguese), Cará tabaco doido (Portuguese)   20.00 cm SL male/unsexed  Known from the upper Negro River basin of the Amazon River basin (Ref. 36377). Also Ref. 1739, 6466. + 
Cichlidae Heros spurius Heckel, 1840 Fr native    15.00 cm SL male/unsexed  Known from the Guaporé River drainage, Amazon River basin (Ref. 36377). + 
Acestrorhynchidae Heterocharax leptogrammus Toledo-Piza, 2000 Fr native   3.39 cm SL male/unsexed  Known from the Negro River (Ref. 36811). Type locality, near mouth of río Arirará, Amazonas (Ref. 38319). + 
Acestrorhynchidae Heterocharax macrolepis Eigenmann, 1912 Fr native   4.75 cm SL male/unsexed   + 
Acestrorhynchidae Heterocharax virgulatus Toledo-Piza, 2000 Fr native  Matapiri (Portuguese)  4.14 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36811). + 
Characidae Heterocheirodon jacuiensis Malabarba & Bertaco, 1999 Fr native  Lambari (Creole, Portuguese)  3.98 cm SL male/unsexed  Found in the Laguna dos Patos drainage (Ref. 37055). Type locality: lagoon at left margin of rio Jacui, near bridge of road BR 290, Cachoeira do Sul (Ref. 34061). - 
Characidae Heterocheirodon yatai (Casciotta, Miquelarena & Protogino, 1992) Fr native  Lambari (Creole, Portuguese)   4.18 cm SL male/unsexed  Recorded from a tributary of the rio Uruguay drainage (Ref. 34061). - 
Loricariidae Hirtella carinata Pereira, Zanata, Cetra & Reis, 2014 Fr native   4.92 cm SL male/unsexed  Recorded from four localities in small rivers and creeks, tributaries to the Rio Panelão, itself a tributary to the lower Rio Pardo drainage, near the town of Camacan in southern Bahia State (Ref. 97864). - 
Loricariidae Hisonotus acuen Silva, Roxo & Oliveira, 2014 Fr native   2.91 cm SL male/unsexed  Known from small to median-sized streams of the upper rio Xingu basin in Mato Grosso State (Ref. 106073). - 
Loricariidae Hisonotus alberti Roxo, Silva, Waltz & Melo, 2016 Fr native   3.41 cm SL male/unsexed  Type locality of Hisonotus alberti from municipality of São Roque de Minas, ribeirão das Posses, upper rio Paraná basin, Minas Gerais State, Brazil, MZUSP 118845. Also known from tributaries of the upper rio Paraná basin: ribeirão das Posses and córrego Caxambú, and one tributary of the upper rio São Francisco basin at córrego Luciano (Ref. 128921). - 
Loricariidae Hisonotus armatus Carvalho, Lehmann A., Pereira & Reis, 2008 Fr native   6.00 cm TL male/unsexed  Type locality, about 5 km south of Vila Basílio, on road to Pedro Osório, Arroio Arambaré, Pedro Osório, Rio Grande do Sul, MCP 41323 (holotype of Hisonotus armatus, 4.44 cm SL, female). Found in Laguna dos Patos system from the southern most Rio Jaguarão drainage, to the Rio Jacuí and Rio Taquari drainages. This is unknown from the headwaters of the Rio Jacuí and Rio Taquari drainages (Ref. 78747). - 
Loricariidae Hisonotus bocaiuva Roxo, Silva, Oliveira & Zawadzki, 2013 Fr native   2.42 cm SL male/unsexed  Known from córrego Cachoeira in Bocaiúva, Minas Gerais (Ref. 95507). - 
Loricariidae Hisonotus bockmanni Carvalho & Datovo, 2012 Fr native   2.11 cm SL male/unsexed ;2.35 cm SL female  Known only from Rio Cururu, tributary to the Rio Teles Pires, which is a tributary to the Rio Tapajós, Amazon basin (Ref. 91046). - 
Loricariidae Hisonotus brunneus Carvalho & Reis, 2011 Fr native   4.15 cm SL male/unsexed  Found in the tributaries of the rio Jacuí drainage, laguna dos Patos system (Ref. 86691). - 
Loricariidae Hisonotus carreiro Carvalho & Reis, 2011 Fr native   3.58 cm SL male/unsexed  Known only from the headwaters of rio Taquari drainage, laguna dos Patos system (Ref. 86691). - 
Loricariidae Hisonotus charrua Almirón, Azpelicueta, Casciotta & Litz, 2006 Fr native    3.59 cm SL male/unsexed   - 
Loricariidae Hisonotus chromodontus Britski & Garavello, 2007 Fr native   3.25 cm SL male/unsexed  Known from the upper Rio Tapajós drainage in Mato Grosso (Ref. 75061). - 
Loricariidae Hisonotus depressicauda (Miranda Ribeiro, 1918) Fr native   5.00 cm SL male/unsexed  Known from the Tietê River basin (Ref. 36885). Type locality: Sorocaba, Rio Paraná (Ref. 26282). - 
Loricariidae Hisonotus depressinotus (Miranda Ribeiro, 1918) Fr native    3.00 cm SL male/unsexed  Known from the Tietê River basin (Ref. 36885). Type locality: Piracicaba, Estado de Sao Paulo, Brazil (Ref. 26282). - 
Loricariidae Hisonotus devidei Roxo, Silva & Melo, 2018 Fr native   3.16 cm SL female  Type locality of the holotype of Hisonotus devidei: Rio São Francisco, Rio Pandeiros, Córrego Catolé, Bonito de Minas, Minas Gerais (Ref. 128922). - 
Loricariidae Hisonotus dinizae Ribeiro-Silva, Silva, Venere, da Silva & Roxo, 2020 Fr native   2.33 cm SL male/unsexed  Type locality of the holotype of Hisonotus dinizae: Rio Araguaia basin, drainage of Rio Pindaíba, córrego Grande, municipality of Barra do Garças, Mato Grosso (Ref. 128923). - 
Loricariidae Hisonotus francirochai (Ihering, 1928) Fr native   3.80 cm SL male/unsexed  Found in the Grande River basin (Ref. 36885). Occurs in the Pardo River, upper Paraná River basin, southeastern Brazil (Ref. 27745). Type locality: Creeks by Pirangy, headwaters of the Rio Turvo (Ref. 6868). + 
Loricariidae Hisonotus heterogaster Carvalho & Reis, 2011 Fr native   4.30 cm SL male/unsexed  Found only in the tributaries of the rio Jacuí drainage, laguna dos Patos system (Ref. 86691). - 
Loricariidae Hisonotus iota Carvalho & Reis, 2009 Fr native   3.34 cm SL female   - 
Loricariidae Hisonotus laevior Cope, 1894 Fr native   7.50 cm TL male/unsexed  Widespread in Laguna dos Patos system from southernmost tributaries of the laguna Mirim and canal São Gonçalo drainage to the tributaries of the northern rio Jacuí basin. Absent in the headwaters of the rio Jacuí basin (Ref. 86691). Also Ref. 6868. - 
Loricariidae Hisonotus leucofrenatus (Miranda Ribeiro, 1908) Fr native    6.00 cm SL male/unsexed  Type locality: Rio das Pedras of Rio Ribeira, Brazil (Ref. 26282). + 
Loricariidae Hisonotus leucophrys Carvalho & Reis, 2009 Fr native   4.22 cm SL male/unsexed   - 
Loricariidae Hisonotus megaloplax Carvalho & Reis, 2009 Fr native   4.71 cm SL male/unsexed   - 
Loricariidae Hisonotus montanus Carvalho & Reis, 2009 Fr native   4.51 cm SL male/unsexed   - 
Loricariidae Hisonotus nigricauda (Boulenger, 1891) Fr native   6.00 cm TL male/unsexed  Known from the Paraná/Paraguay River basin (Ref. 36885). Type locality: Rio Grande do Sul (Ref. 6868). - 
Loricariidae Hisonotus notatus Eigenmann & Eigenmann, 1889 Fr native  Cascudinho (Portuguese)   4.33 cm SL male/unsexed  Type locality: Santa Cruz and Juiz de For a (Ref. 6868). - 
Loricariidae Hisonotus notopagos Carvalho & Reis, 2011 Fr native   3.73 cm SL male/unsexed  Known from rio Camaquã drainage, laguna dos Patos system (Ref. 86691). - 
Loricariidae Hisonotus pachysarkos Zawadzki, Roxo & da Graça, 2016 Fr native    Type locality of Hisonotus pachysarkos from rio Ivaí basin, upper rio Paraná system (Ref. 128933). - 
Loricariidae Hisonotus paulinus (Regan, 1908) Fr native   4.00 cm SL male/unsexed  Known from the Tietê River basin (Ref. 36885). Type locality: Rio Piracicaba, Sao Paulo, Brazil (Ref. 6868). - 
Loricariidae Hisonotus prata Carvalho & Reis, 2011 Fr native   3.32 cm SL male/unsexed  Known only from the headwaters of rio Taquari drainage, laguna dos Patos system (Ref. 86691). - 
Loricariidae Hisonotus ringueleti Aquino, Schaefer & Miquelarena, 2001 Fr native    4.34 cm SL male/unsexed   + 
Loricariidae Hisonotus taimensis (Buckup, 1981) Fr native   6.60 cm SL male/unsexed  Known from the Lago Mirim drainage (Ref. 36885). Type locality: Novo canal do Arroio Taim, Estaçao Ecológica do Taim, Rio Grande do Sul, Brazil (Ref. 26282). + 
Loricariidae Hisonotus thayeri Martins & Langeani, 2016 Fr native   4.20 cm SL male/unsexed  Known from the coastal basins of rio Paraíba do Sul, Lagoa Feia, rio Macaé, rio Itabapoana, rio Itapemirim, rio Novo, rio Benevente, and rio Doce in Minas Gerais, Rio de Janeiro and Espírito Santo states (Ref. 109747). Status of threat: Least Concern (LC) (Ref. 109747). - 
Loricariidae Hisonotus vespuccii Roxo, Silva & Oliveira, 2015 Fr endemic    2.87 cm SL male/unsexed ;3.57 cm SL female  Found in the rio São Francisco and in three of its tributaries, rio das Velhas, rio Paraopeba and rio Formoso (Ref. 114934). - 
Loricariidae Hisonotus vireo Carvalho & Reis, 2011 Fr native   3.95 cm SL male/unsexed  Known from Rio Jacuí basin, laguna dos Patos system (Ref. 86691). - 
Characidae Hollandichthys multifasciatus (Eigenmann & Norris, 1900) Fr native  Lambari-listrado (Portuguese), Lambari (Portuguese)   9.64 cm SL male/unsexed  Occurs in Betari River basin (Ref. 38979). + 
Characidae Hollandichthys taramandahy Bertaco & Malabarba, 2013 Fr native   8.78 cm SL male/unsexed  Known from the tributaries of the rio Maquiné and rio Três Forquilhas, rio Tramandaí system in Rio Grande do Sul and from rio Mampituba and Araranguá drainages in Santa Catarina. Extensive sampling efforts for the last 30 years in the rio Maquiné, rio Três Forquilhas and rio Mampituba drainages did not encounter this species in the main river itself, characterized by having clear and lotic water, stones on the substrate, and few riparian vegetation (Ref. 94715). - 
Trichomycteridae Homodiaetus anisitsi Eigenmann & Ward, 1907 Fr native    4.90 cm TL male/unsexed    - 
Trichomycteridae Homodiaetus banguela Koch, 2002 Fr native   3.80 cm SL male/unsexed  Found in São João River, coastal basin of southeastern Brazil in Rio de Janeiro (Ref. 39970). Type locality, Rio São João, Silva Jardim, Rio de Janeiro state (Ref. 50838). - 
Trichomycteridae Homodiaetus graciosa Koch, 2002 Fr native  Cambeba (Portuguese)   3.50 cm SL male/unsexed  Found in coastal basins of southeastern Brazil in Paraná and São Paulo (Re. 39970). Type locality, Rio Florestal, Rio Sagrado, Morretes, Paraná (Ref. 50838). - 
Trichomycteridae Homodiaetus passarellii (Miranda Ribeiro, 1944) Fr native    3.80 cm SL male/unsexed  Found in coastal basins in Rio de Janeiro (Ref. 39970). Type locality: Córrego do Barro Branco, Baia de Guanabara, Estado do Rio de Janeiro, Brazil (Ref. 26282, 6868). - 
Cichlidae Hoplarchus psittacus (Heckel, 1840) Fr native  Acará paragaio (Portuguese), Acarra (Portuguese)   32.00 cm TL male/unsexed  Known from the Río Negro (Ref. 12251). + 
Loricariidae Hopliancistrus munduruku Oliveira, Zuanon, Rapp Py-Daniel, Birindelli & Sousa, 2021 Fr native   15.53 cm SL male/unsexed  Type locality of Hopliancistrus munduruku, Pará, Altamira, Curuá River, tributary of Iriri River, on Castelo dos Sonhos Village. The disjunct distribution between upper tributaries to Tapajós and Xingu basin suggests drainage capture by geologic events. Currently found from the upper Rio Jamanxim, Rio Tapajo´s basin, and upper Rio Curuá, tributary of Rio Iriri, Rio Xingu basin, in the Novo Progresso municipality, Pará State (Ref. 125999). - 
Loricariidae Hopliancistrus tricornis Isbrücker & Nijssen, 1989 Fr endemic   13.67 cm SL male/unsexed  Type locality of Hopliancistrus tricornis, Pará State, São Luis, Poça de Pedra on Rio Tapajós. Known to be restricted to the middle part of Rio Tapajós basin in the São Luiz rapids, its main tributaries, such as the lower part of Rio Jamanxim and Rio Itapacura; also in small tributaries, such as Igarape Leitoso, tributary of the Rio Cupari, Ruropolis municipality (Ref. 125999). - 
Loricariidae Hopliancistrus wolverine Oliveira, Zuanon, Rapp Py-Daniel, Birindelli & Sousa, 2021 Fr native   18.18 cm SL male/unsexed  Type locality of Hopliancistrus wolverine, Pará State, Altamira, Rio Xingu, Pimental Furo da Crente. Known from the middle Rio Xingu, immediately downriver of the Belo Monte Village, throughout the Volta Grande do Xingu, to the vicinity of São Félix do Xingu, and in the Rio Iriri, immediately upstream its confluence to Xingu until the mouth of the Rio Curuá (Ref. 125999). - 
Loricariidae Hopliancistrus xavante Oliveira, Zuanon, Rapp Py-Daniel, Birindelli & Sousa, 2021 Fr native   11.65 cm SL male/unsexed  Type locality of Hopliancistrus xavante, Mato Grosso, Paranatinga, Rio Culuene, small hydroelectric powerplant Paranatinga 2 coffeudam, Known from small tributaries of the middle part of Rio Xingu (Fresco and Jauri rivers) and upper Rio Xingu basin at Cachoeira von Martius and its tributaries such as Rio Culuene, Rio Curisevo, and Rio Sucuri (Ref. 125999). - 
Loricariidae Hopliancistrus xikrin Oliveira, Zuanon, Rapp Py-Daniel, Birindelli & Sousa, 2021 Fr native   14.16 cm SL male/unsexed  Type locality of Hopliancistrus xikrin, Pará, Altamira, Rio Bacajá, ca. 2 km upstream from confluence with Rio Xingu. Known from small to medium-sized tributaries of the middle portion of Rio Xingu, like Rio Bacajá and Rio Bacajaí, at the Volta Grande area (Ref. 125999). - 
Erythrinidae Hoplias aimara (Valenciennes, 1847) Fr native  Traira (Portuguese), Traíra gigante (Portuguese), Trairão (Portuguese)  100.00 cm SL male/unsexed  Known from the Rios Araguari and Amapá, state of Amapá (Ref. 57715). + 
Erythrinidae Hoplias australis Oyakawa & Mattox, 2009 Fr native   44.39 cm SL male/unsexed  Known from the rio Uruguay basin (Ref. 81195). + 
Erythrinidae Hoplias brasiliensis (Spix & Agassiz, 1829) Fr native  Traíra (Portuguese)   20.30 cm SL male/unsexed  Known from the coastal rivers of NE Brazil, from the rio Paraguaçú in Bahia State to rio Jequitinhonha in Minas Gerais and Espírito Santo States, including rio de Contas and rio Pardo (Ref. 81195). Also Ref. 37025. - 
Erythrinidae Hoplias curupira Oyakawa & Mattox, 2009 Fr native   29.88 cm SL male/unsexed  Known from the rivers of the Amazon basin including rios Capim, Tocantins, Xingu and Tapajós on the right bank of the rio Amazonas and rios Trombetas and Negro on the left bank, including upper tributaries of the rio Negro (rios Tiquié and Uaupés) (Ref. 81195). - 
Erythrinidae Hoplias intermedius (Günther, 1864) Fr native    60.00 cm SL male/unsexed  Type locality, São Francisco basin, Minas Gerais State. Disjunct distribution, known from the upper streches of rio São, rio Doce and rio Paraná basin (not known downstream of Sete Quedas); also in rios Grande, Paranaíba, Piquiri and in the tributaries of rio Doce, Minas Gerais State (Ref. 81195). - 
Erythrinidae Hoplias lacerdae Miranda Ribeiro, 1908 Fr, Fi, Aq native  Tariputanga (Portuguese), Trairaçu (Portuguese), Trairão (Portuguese)   75.00 cm SL male/unsexed  Found in Ribeira de Iguape River basin in São Paulo and Paraná (Ref. 37025). Reported from the Uruguay River (Ref. 79585). + 
Erythrinidae Hoplias macrophthalmus (Pellegrin, 1907) Fr native  Aimara (Portuguese), Traíra (Portuguese), Trairão (Portuguese)  100.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 37025). + 
Erythrinidae Hoplias malabaricus (Bloch, 1794) Fr, Fi, Aq native  Traíra (Portuguese), Cipó de viúva (Portuguese), Dorme-dorma (Portuguese), Dorme-dorme (Portuguese), Jeju (Portuguese), Lobó (Portuguese), Lolaia (Portuguese), Pau de negro (Portuguese), Peixe preto (Portuguese), Robafo (Portuguese), Rubafo (Portuguese), Sabira (Portuguese), Taraíra (Portuguese), Tariíra (Portuguese), Traira (Portuguese), Traïra (Portuguese), Trairitinga (Portuguese) scarce (very unlikely) 65.00 cm TL male/unsexed 16.7 TL Occurs in the Pardo River, upper Paraná River basin, southeastern Brazil (Ref. 27745), Pircacicaba (Ref. 50076), Patos lagoon (Ref. 58359), Uruguay (Ref. 79585), Machado (Ref. 97589) and Acre River basins (Ref. 97592). Also Ref. 6029, 37025, 31923. + 
Erythrinidae Hoplias microcephalus (Agassiz, 1829) Fr native  Traíra (Portuguese)   35.60 cm SL male/unsexed  Known from São Francisco River basin (Ref. 37025). - 
Acestrorhynchidae Hoplocharax goethei Géry, 1966 Fr native    3.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36811). + 
Callichthyidae Hoplosternum littorale (Hancock, 1828) Fr, Fi native  Caborja (Portuguese), Atipa (Portuguese), Camboatá (Portuguese), Cascudo (Portuguese), Curite (Portuguese), Tamboatá (Portuguese), Tamoatá (Portuguese), Tamuata (Portuguese), Tamuatá (Portuguese)   26.30 cm TL male/unsexed  Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). Also known from Pará (Ref. 26144), Piracicaba (Ref. 31923) and Machado River basins (Ref. 97589). Also Ref. 37395. + 
Heptapteridae Horiomyzon retropinnatus Stewart, 1986 Fr native    2.40 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36914). - 
Cynodontidae Hydrolycus armatus (Jardine, 1841) Fr native  Pirantera (Portuguese), Cachorra (Portuguese), Pirandirá (Portuguese)   89.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 38270). + 
Cynodontidae Hydrolycus scomberoides (Cuvier, 1819) Fr, Fi native  Cachorra (Portuguese), Cachorro (Portuguese), Gata (Portuguese), Paraya (Portuguese), Peixe cachorro (Portuguese), Peixe-cachorra (Portuguese), Pirandirá (Portuguese), Piranha (Portuguese), Saranha do rabo amarelo (Portuguese)   117 cm TL male/unsexed  Found in fish markets in Santarém (Ref. 12202). Probably a misidentification (occurrence in this country not confirmed by M.Toledo-Piza). + 
Cynodontidae Hydrolycus tatauaia Toledo-Piza, Menezes & Santos, 1999 Fr native  Pirandirá (Portuguese), Cachorra (Portuguese), Pirantera (Portuguese), Wismati (Portuguese)  59.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 38270). + 
Cynodontidae Hydrolycus wallacei Toledo-Piza, Menezes & Santos, 1999 Fr native  Pirantera tariyari (Portuguese)   36.00 cm SL male/unsexed  Known from the Negro River basin (Ref. 38270). - 
Loricariidae Hypancistrus phantasma Tan & Armbruster, 2016 Fr native   12.33 cm SL male/unsexed  Known from Rio Uaupes, Rio Negro drainage, Amazon basin, Taracuá (Ref. 114591). - 
Loricariidae Hypancistrus zebra Isbrücker & Nijssen, 1991 Fr endemic  Zebra pleco (English), Cascudo zebra (Portuguese)   7.00 cm TL male/unsexed  Known from Rio Xingu, Pará (Ref. 26754). Also Ref. 36713. + 
Characidae Hyphessobrycon agulha Fowler, 1913 Fr native    4.31 cm SL male/unsexed  Recorded from the Amazon (Ref. 598), Madeira (Ref. 38376) and Machado river basin (Ref. 97589). - 
Characidae Hyphessobrycon amandae Géry & Uj, 1987 Fr native   2.03 cm SL male/unsexed  Museum: Rio das Mortes, Mato Grosso, MZUSP 37367 (holotype of H. amandae, 1.9 cm SL) (Ref. 27925). + 
Characidae Hyphessobrycon amapaensis Zarske & Géry, 1998 Fr endemic   2.99 cm SL male/unsexed  Amapa Territory, in the vicinity of Macapa. + 
Characidae Hyphessobrycon balbus Myers, 1927 Fr native    6.00 cm TL male/unsexed  Recorded from Planaltina, Lagoa Fervedeira, Goiás (Ref. 26282). - 
Characidae Hyphessobrycon bentosi Durbin, 1908 Fr native  Piaba (Portuguese)   4.32 cm SL male/unsexed  Widely distributed in the Rio Amazonas. Reported from Machado river basin (Ref. 97589). + 
Characidae Hyphessobrycon bifasciatus Ellis, 1911 Fr native  Lambari (Portuguese), Piaba (Portuguese), Piabinha (Portuguese), Tetra amarelo (Portuguese)   4.70 cm TL male/unsexed  Recorded from the Patos lagoon (Ref. 58359). Also Ref. 598 and 4537. + 
Characidae Hyphessobrycon boulengeri (Eigenmann, 1907) Fr native  Lambari (Portuguese)  4.50 cm TL male/unsexed  Recorded from the Rio Grande do Sol. - 
Characidae Hyphessobrycon brumado Zanata & Camelier, 2010 Fr native  Piaba (Portuguese)  3.16 cm SL male/unsexed  Known from the rio Brumado, tributary of the rio de Contas, a coastal drainage of eastern Brazil (Ref. 85847). - 
Characidae Hyphessobrycon cachimbensis Travassos, 1964 Fr native   4.91 cm SL male/unsexed  Known from the Cachimbo River, Tapajós River basin (Ref. 38376) in Pará (Ref. 96859). Also Ref. 598. - 
Characidae Hyphessobrycon coelestinus Myers, 1929 Fr native   3.31 cm SL male/unsexed  Recorded from Goiás (Ref. 26282). + 
Characidae Hyphessobrycon comodoro Dagosta, Seren, Ferreira & Marinho, 2022 Fr native  Emerald green tetra (English)  3.86 cm SL male/unsexed  Type locality of Hyphessobrycon comodoro, Mato Grosso State, Municipality of Comodoro, lagoon at tributary of the rio Mutum, formed due to the construction of a road, tributary of rio Camararé, upper rio Juruena basin, rio Tapajós basin. Known from headwater of the rio Mutum, tributary of the rio Camararé, upper rio Juruena basin at Chapada dos Parecis, Mato Grosso State (Ref. 128640). + 
Characidae Hyphessobrycon copelandi Durbin, 1908 Fr native    5.00 cm TL male/unsexed  Reported from the middle and upper reaches of the Amazon basin (Ref. 12225). Found in Machado river basin (Ref. 97589). + 
Characidae Hyphessobrycon cyanotaenia Zarske & Géry, 2006 Fr native   3.66 cm SL male/unsexed   + 
Characidae Hyphessobrycon diancistrus Weitzman, 1977 Fr native    3.72 cm SL male/unsexed ;2.50 cm SL female    + 
Characidae Hyphessobrycon diastatos Dagosta, Marinho & Camelier, 2014 Fr native   2.67 cm SL male/unsexed  Known from the from tributaries of the rio Grande (rio São Francisco basin) draining east to the Serra Geral de Goiás, from the rio São Domingos (upper rio Tocantins basin) and rio do Sono basins (middle rio Tocantins basin) (Ref. 102657). - 
Characidae Hyphessobrycon dorsalis Zarske, 2014 Fr native   3.65 cm SL male/unsexed  Known from the rio Caures basin, Amazonas (Ref. 96662). + 
Characidae Hyphessobrycon duragenys Ellis, 1911 Fr native    6.80 cm TL male/unsexed  Recorded from Parahyba and Tieté rivers. + 
Characidae Hyphessobrycon eilyos Lima & Moreira, 2003 Fr native   2.47 cm male/unsexed  Known from córrego do Rancho and ribeirão do Sapo, both tributaries of the upper rio Araguaia basin in the state of Mato Grosso, Brazil (Ref. 52338). + 
Characidae Hyphessobrycon elachys Weitzman, 1984 Fr native   2.00 cm SL male/unsexed  Known from the Paraguay River (Ref. 38376). + 
Characidae Hyphessobrycon epicharis Weitzman & Palmer, 1997 Fr native   3.30 cm SL male/unsexed   + 
Characidae Hyphessobrycon eques (Steindachner, 1882) Fr native  Mato grosso (Portuguese), Mato-grosso (Portuguese)   4.00 cm SL male/unsexed 3 TL Recorded from the Amazon River near Villa Bella and Obidos. + 
Characidae Hyphessobrycon ericae Moreira & Lima, 2017 Fr native   3.97 cm SL male/unsexed  Found in the lower rio Trombetas basin and the adjacent small rio Jamari basin at the northern bank of the Amazon River, the rio Curuá-Una basin at the southern bank of the Amazon basin, and westward to tributaries of the middle rio Madeira basin in Pará, Amazonas, and Rondônia states (Ref. 116179). - 
Characidae Hyphessobrycon erythrostigma (Fowler, 1943) Fr native   6.06 cm SL male/unsexed  Found in the Amazon River (Ref. 38376). + 
Characidae Hyphessobrycon flammeus Myers, 1924 Fr, Or endemic  Engraçadinho (Portuguese), Lambarizinho vermelho (Portuguese), Rio tetra (Portuguese)   2.61 cm SL male/unsexed  Found in streams and coastal rivers of Rio de Janeiro State, in Guanabara bay basin, middle rio Paraíba do Sul basin and rio Guandu basin; and in the upper rio Tietê drainage (upper rio Paraná basin, São Paulo State) (Ref. 96863). Also Ref. 598, 38376. + 
Characidae Hyphessobrycon griemi Hoedeman, 1957 Fr, Or endemic  Engraçadinho (Portuguese)  2.92 cm SL male/unsexed  Found in eastern coastal rivers from São Paulo to northern Santa Catarina (Ref. 38376). Also Ref. 598, 4537. + 
Characidae Hyphessobrycon hamatus Bertaco & Malabarba, 2005 Fr native   4.48 cm SL male/unsexed  Known from two tributaries of the rio Vermelho, in the headwaters of the rio Tocantins basin, Mambaí, Goiás, Brazil. - 
Characidae Hyphessobrycon haraldschultzi Travassos, 1960 Fr native   2.10 cm TL male/unsexed  Recorded from the Rio Araguaia drainage, Ilha do Bananal. + 
Characidae Hyphessobrycon hasemani Fowler, 1913 Fr native    2.80 cm SL male/unsexed  Recorded from the Madeira river above falls of Guajaramirim. + 
Characidae Hyphessobrycon heliacus Moreira, Landim & Costa, 2002 Fr native   2.78 cm SL male/unsexed  Known from the 5 tributaries of the rio Téles Pires, in the upper rio Tapajós basin. Type locality, riobeirão Macuco (= córrego Duas-bocas), tributary of the rio Teles Pires, rio Tapajós basin, 71.9 km north from Sinop, município de Cláudia, at BR-163 road in the direction to Santarém,, Estado de Mato Grosso. + 
Characidae Hyphessobrycon herbertaxelrodi Géry, 1961 Fr, Or endemic  Neon-negro (Portuguese)  3.23 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 38376). Recorded from Mato Grosso (Ref. 598). + 
Characidae Hyphessobrycon heteresthes (Ulrey, 1894) Fr native   1.70 cm TL male/unsexed   - 
Characidae Hyphessobrycon heterorhabdus (Ulrey, 1894) Fr native  Bandeira alemã (Portuguese), Risca fogo (Portuguese), Tetra bandeira (Portuguese)   3.56 cm TL male/unsexed  Recorded from the Amazon (Ref. 38376). + 
Characidae Hyphessobrycon hexastichos Bertaco & Carvalho, 2005 Fr native    Known from the upper rio Tapajós in Mato Grosso (Ref. 56786). + 
Characidae Hyphessobrycon iheringi Fowler, 1941 Fr native   4.20 cm SL male/unsexed  Recorded from Ceara. - 
Characidae Hyphessobrycon inconstans (Eigenmann & Ogle, 1907) Fr native   4.50 cm TL male/unsexed  Known from Pará (Ref. 38376). - 
Characidae Hyphessobrycon itaparicensis Lima & Costa, 2001 Fr native    3.84 cm SL male/unsexed  Found in coastal streams in eastern Brazil (Ref. 38376). Type locality, small stream in ilha de Itaparica, Estado de Bahia, Brazil (Ref. 38376). + 
Characidae Hyphessobrycon kayabi Teixeira, Lima & Zuanon, 2014 Fr native   2.84 cm SL male/unsexed  Known so far from the lower Rio Teles Pires basin downstream from the confluence with Rio Apiacás, near the border between Mato Grosso and Pará states (Ref. 94770). - 
Characidae Hyphessobrycon khardinae Zarske, 2008 Fr native   3.94 cm SL male/unsexed  Type locality, rio Itaparana, Amazon, MZUSP 98667 (holotype of Hyphessobrycon khardinae, 3.94 cm SL) (Ref. 75699). - 
Characidae Hyphessobrycon langeanii Lima & Moreira, 2003 Fr native   5.85 cm SL male/unsexed  Known from several streams in the upper rio Araguaia basin, states of Mato Grosso and Goiás (Ref. 52338). - 
Characidae Hyphessobrycon latus Fowler, 1941 Fr native   5.00 cm SL male/unsexed  Recorded from Ceara. - 
Characidae Hyphessobrycon loweae Costa & Géry, 1994 Fr native   3.16 cm SL male/unsexed  Recorded from Estado de Matto Groso. Corrego Xavante, a tributary of the Rio Culuene, Rio Xingu basin. Also Ref. 27925. + 
Characidae Hyphessobrycon maculicauda Ahl, 1936 Fr native   4.30 cm TL male/unsexed   - 
Characidae Hyphessobrycon megalopterus (Eigenmann, 1915) Fr native  Tetra fantasma (Portuguese)   3.64 cm SL male/unsexed  Recorded from the Río Guaporé. May also occur in the upper Río Paraguay. Found in Pantanal (Ref. 81048). Also Ref. 38376. + 
Characidae Hyphessobrycon melanostichos Carvalho & Bertaco, 2006 Fr native   3.73 cm SL male/unsexed  Found only in the rio Doze de Outubro, a tributary of the rio Juruena, in the upper rio Tapajós basin, Chapada dos Parecis, Comodoro, Mato Grosso (Ref. 57598). Recorded from the Lagoa Azul, rio Paraguay basin in Mato Grosso (Ref. 96859). + 
Characidae Hyphessobrycon melasemeion Fowler, 1945 Fr questionable   3.88 cm SL male/unsexed   - 
Characidae Hyphessobrycon melazonatus Durbin, 1908 Fr native   3.80 cm TL male/unsexed  Found in the Amazon River basin (Ref. 38376). - 
Characidae Hyphessobrycon meridionalis Ringuelet, Miquelarena & Menni, 1978 Fr native  Lambari (Portuguese)  5.00 cm SL male/unsexed  Recorded from the Patos lagoon (Ref. 58359). Found in coastal river basins of Rio Grande do Sul (Ref. 38376). - 
Characidae Hyphessobrycon micropterus (Eigenmann, 1915) Fr native  Piabinha (Portuguese)   2.70 cm SL male/unsexed  Recorded from Bahia, Sao Francisco drainage, Barra (also called Barra do Rio Grande, Lagoa do Porto). + 
Characidae Hyphessobrycon moniliger Moreira, Lima & Costa, 2002 Fr native   3.05 cm SL male/unsexed  Found in the Araguaia-Tocantins River and upper Tapajós River basin (Ref. 38376). Recorded from rio Paranã, rio Tocantins basin in Monte Alegre de Goiás, Goiás (Ref. 96859). Type locality, rio Água Fria basin, Tocantins (Ref. 42938). + 
Characidae Hyphessobrycon montagi Lima, Coutinho & Wosiacki, 2014 Fr native   3.11 cm SL male/unsexed  Known from the headwaters of the rio Arapiuns (rio Branco and rio Aruã), lower rio Tapajós basin, and from a small direct tributary of the Rio Amazonas (igarapé da Ponte) in Juruti municipality, Pará state (Ref. 97524). - 
Characidae Hyphessobrycon mutabilis Costa & Géry, 1994 Fr native   2.69 cm SL male/unsexed  Type locality, tributary of Rio Sete de Setembro, Rio Xingú basin, 107 km southwest Canarana, Estado de Mato Grosso, MNRJ 12438 (holotype of Hyphessobrycon mutabilis, 2.32 cm SL) (Ref. 72430). Museum: MZUSP 45292, Buriti palm Cabiseru, rio Suia-Missu drainage, MZUSP 45752. Caterpillar swamp, 18 km of base camp, MZUSP 45753 (Ref. 27925). - 
Characidae Hyphessobrycon myrmex Pastana, Dagosta & Esguícero, 2017 Fr native   2.38 cm SL male/unsexed  Type locality of Hyphessobrycon myrmex, Mato Grosso, Campos de Júlio, Rio Formiga at PCH Divisa, upper Rio Juruena, Rio Tapajós basin. The Rio Formiga is a right-bank tributary of the Rio Juína, in the headwaters of the Rio Juruena, a hydroelectric reservoir (PCH Divisa) was built here in 2010. Before the dam construction, Rio Formiga, with an area of 6·8 km2, would have resembled the adjacent up and downstream areas of the river, i.e. a relative narrow (10-15 m wide) and shallow (maximum depth ca. 1·8 m in some sites) river stretch, characterized by rapid waters and rifles (Ref. 128641). + 
Characidae Hyphessobrycon negodagua Lima & Gerhard, 2001 Fr native   2.82 cm SL male/unsexed  Found in the upper Paraguaçú River basin (Ref. 38376). + 
Characidae Hyphessobrycon notidanos Carvalho & Bertaco, 2006 Fr native   2.86 cm SL male/unsexed  Found only in Rio Doze de Outubro of the upper rio Tapajós basin in Chapada dos Parecis, Comodoro, Mato Grosso (Ref. 57598). - 
Characidae Hyphessobrycon paepkei Zarske, 2014 Fr native   3.38 cm SL male/unsexed  Known from the rio Demini basin, Amazonas (Ref. 96662). + 
Characidae Hyphessobrycon parvellus Ellis, 1911 Fr native  Piabinha (Portuguese)   2.16 cm SL male/unsexed  Found in the Catu and Itapicuru rivers in northeastern Bahia (Ref. 38376). - 
Characidae Hyphessobrycon peugeotorum Ingenito, Lima & Buckup, 2013 Fr native   3.17 cm SL male/unsexed  Found in the tributaries of the middle rio Juruena, upper rio Tapajós basin in Mato Grosso State (Ref. 93222). - 
Characidae Hyphessobrycon piabinhas Fowler, 1941 Fr native  Piabinha (Portuguese)  3.20 cm SL male/unsexed  Recorded from Fortaleza, Ceará (Ref. 38376). - 
Characidae Hyphessobrycon pinnistriatus Carvalho, Cabeceira & Carvalho, 2017 Fr native    Type locality of Hyphessobrycon pinnistriatus, Mato Grosso State, Municipality of Novo Mundo, Parque Estadual Cristalino, igarapé affluent of Rio Cristalino. It is known from the Rio Teles Pires drainages, an affluent of the upper Rio Tapajós, Tapajós-Juruena ecoregion, Mato Grosso State (Ref. 118106). - 
Characidae Hyphessobrycon procyon Pastana & Ohara, 2016 Fr native   3.22 cm SL male/unsexed  Type locality of Hyphessobrycon procyon, Brazil, Amazonas, Apuí, rio Juma on road BR 230 between Vila dos 180 and Apuí, rio Aripuanã drainage. Known only from rio Juma and one of its tributaries, rio Aripuanã drainage, rio Madeira basin, Apuí town, Amazonas State. Status of threast: Since it is so far known only from the rio Apuí and one of its tributaries, its conservation status is uncertain based on the currently available data of its geographic distribution. However, since no imminent threats to the species were detected in the area of occurrence, it was suggested that this species should be classified as Least Concern (LC) according to the International Union for Conservation of Nature (IUCN) categories and criteria (IUCN Standards and Petitions Subcommittee, 2014) (Ref. 128639). + 
Characidae Hyphessobrycon pulchripinnis Ahl, 1937 Fr endemic  Tetra limão (Portuguese)  3.80 cm SL male/unsexed ;3.60 cm SL female  Found in the Tapajós River basin (Ref. 38376). Recorded from the Amazonas (Ref. 13676). Also Ref. 598. + 
Characidae Hyphessobrycon pyrrhonotus Burgess, 1993 Fr native   4.54 cm SL male/unsexed  Recorded from the Rio Erere, tributary of the Rio Negro, Amazonas (Ref. 13676). Museum: Rio Erere, tributary of Rio Negro, MZUSP 45714 (holotype o fH. pyrrhonotus, 4.24 cm SL) (Ref. 27925). + 
Characidae Hyphessobrycon reticulatus Ellis, 1911 Fr native    5.28 cm SL male/unsexed  Found in coastal river drainages from Rio de Janeiro to northern Santa Catarina (Ref. 38376). + 
Characidae Hyphessobrycon rheophilus Ohara, Teixeira, Albornoz-Garzón, Mirande & Lima, 2019 Fr native   4.22 cm SL male/unsexed  Type locality of the holotype of Hyphessobrycon rheophilus: rapids downstream, Cachoeira de Dardanelos, Rio Aripuanã, Aripuanã, Mato Grosso (Ref. 121599). - 
Characidae Hyphessobrycon rosaceus Durbin, 1909 Fr, Or questionable    3.42 cm SL male/unsexed  An aquarium fish without locality, thought to have been obtained in Brazil (Ref. 13676). Reported from Machado river basin (Ref. 97589). + 
Characidae Hyphessobrycon rutiliflavidus Carvalho, Langeani, Miyazawa & Troy, 2008 Fr native   5.81 cm SL male/unsexed  Presently found only in the córrego Pipa of the upper rio Paraguai in Mato Grosso (Ref. 74929). + 
Characidae Hyphessobrycon santae (Eigenmann, 1907) Fr native  Piabinha (Portuguese)   7.11 cm SL male/unsexed  Found in the São Francisco River basin (Ref. 38376). - 
Characidae Hyphessobrycon schauenseei Fowler, 1926 Fr native   3.10 cm SL male/unsexed  Recorded from Rio Inhangapy, Pará. - 
Characidae Hyphessobrycon scholzei Ahl, 1937 Fr endemic  Tetra preto (Portuguese)  4.00 cm TL male/unsexed  Found in the lower Amazon River basin (Ref. 38376). Recorded from the Para (Ref. 598). - 
Characidae Hyphessobrycon scutulatus Lucena, 2003 Fr native   3.50 cm SL male/unsexed  Known only from the type locality, rio Kaiapá drainage, a rio Teles Pires tributary of the rio Tapajós system (Ref. 54770). - 
Characidae Hyphessobrycon socolofi Weitzman, 1977 Fr native   5.63 cm SL male/unsexed  Museum: Barcelos, Rio Negro, Amazonas, MZUSP 13181 (holotype of H. socolofi, 3.89 cm SL) (Ref. 27925). + 
Characidae Hyphessobrycon stegemanni Géry, 1961 Fr native   3.12 cm SL male/unsexed  Recorded from the lower Tocantins (Ref. 598). + 
Characidae Hyphessobrycon stramineus Durbin, 1918 Fr native   3.80 cm TL male/unsexed  Recorded from Tabatinga, Amazon River, Amazonas. - 
Characidae Hyphessobrycon takasei Géry, 1964 Fr native   3.02 cm SL male/unsexed  Found in the Araguari (Ref. 38376). Type locality: Seera do Navio above Macapá, Amapá Terr., Lower Amazon basin (Ref. 12965). + 
Characidae Hyphessobrycon taurocephalus Ellis, 1911 Fr native  Lambari (Portuguese)   5.50 cm TL male/unsexed  Recorded from Rio Iguaçu at Serrinha Paraná, Brazil (Ref. 26282). - 
Characidae Hyphessobrycon togoi Miquelarena & López, 2006 Fr native    5.60 cm SL male/unsexed ;6.84 cm SL female   - 
Characidae Hyphessobrycon tropis Géry, 1963 Fr native   2.13 cm SL male/unsexed  Recorded from the Rio Negro. - 
Characidae Hyphessobrycon tukunai Géry, 1965 Fr native   2.06 cm SL male/unsexed  Known from the upper Amazon (Ref. 598). Found in the upper Solimões River basin (Ref. 38376). - 
Characidae Hyphessobrycon uaiso Carvalho & Langeani, 2013 Fr native   5.29 cm SL male/unsexed  Known from the rio Uberaba, rio Grande drainage, upper rio Paraná basin. Preferably to be classified as data deficient (DD) until more information about its biology and occurrence on the basin is available (Ref. 94154). - 
Characidae Hyphessobrycon vilmae Géry, 1966 Fr endemic   2.94 cm SL male/unsexed  Known the upper Tapajós River basin (Ref. 38376). Recorded from the upper Rio Juruena (Ref. 598). + 
Characidae Hyphessobrycon vinaceus Bertaco, Malabarba & Dergam, 2007 Fr native   6.28 cm SL male/unsexed  Found only in rio São João, in the headwaters of the rio Pardo drainage, a coastal drainage in eastern Brazil (Ref. 75059). - 
Characidae Hyphessobrycon wadai Marinho, Dagosta, Camelier & Oyakawa, 2016 Fr native   3.50 cm SL male/unsexed  Found in the tributaries of the Rio do Sangue, affluent of the Rio Juruena, upper Rio Tapajós basin. Habitat of this species is relatively near human settlement and regions with intense riparian forest degradation for pasture, which may pose threat to its survival. It is preferable to consider this species as data deficient due to its unknown population biology and geographical range reductions. Thus, this species should be under data deficient (DD) classiification of the IUCN categories and criteria (Ref. 109743). + 
Characidae Hyphessobrycon weitzmanorum Lima & Moreira, 2003 Fr native    Known from tributaries of the upper rio Araguaia basin in the state of Mato Grosso, Brazil (Ref. 52338). + 
Characidae Hyphessobrycon werneri Géry & Uj, 1987 Fr native   3.20 cm SL male/unsexed  Recorded from the Rio Guama basin (Ref. 13676). Museum: forest creek between Santa Maria do Pará and Sao Miguel de Guama, mouth of Rio Guamá, Pará, MZUSP 42365 (holotype of H. werneri, 3.2 cm SL) (Ref. 27925). + 
Characidae Hyphessobrycon wosiackii Moreira & Lima, 2017 Fr native   3.45 cm SL male/unsexed  Found only in the Igarapé Juruti Grande, a direct tributary of the Rio Amazonas, Pará state, near the border with Amazonas state (Ref. 116179). - 
Characidae Hyphessobrycon zoe Faria, Lima & Wosiacki, 2020 Fr native   2.97 cm SL male/unsexed  Type locality of Hyphessobrycon zoe, Pará, Obidos,Estacao Ecologica Grao Pará Centro, stream tributary of Rio Urucuriana, Rio Paru do Oeste basin. Known from small tributaries of the Rio Urucuriana, a tributary of Rio Paru do Oeste, which itself is a tributary of the Rio Trombetas basin, Amazon basin, Pará State (Ref. 125533). - 
Characidae Hypobrycon leptorhynchus da Silva & Malabarba, 1996 Fr native   4.76 cm SL male/unsexed  Type locality: Rio Ibicuí, near pulp mill plant, ca. 27°33'S, 51°12'W, Rio Uruguai drainage, Campos Novos, Santa Catarina, Brazil. - 
Characidae Hypobrycon maromba Malabarba & Malabarba, 1994 Fr native   4.84 cm SL male/unsexed  Found in the upper Uruguay River basin (Ref. 38376). Type locality: Rio das Marombas, under Irineu Bronhausen bridge, Santa Catarina, Brazil (Ref. 26618). - 
Achiridae Hypoclinemus mentalis (Günther, 1862) Fr native  Linguado (Portuguese)   21.60 cm SL male/unsexed    + 
Anostomidae Hypomasticus copelandii (Steindachner, 1875) Fr native  Piava-vermelha (Portuguese), Piaba (Portuguese)   54.00 cm TL male/unsexed  Type locality of Leporinus copelandii. Known from Paraíba do Sul and Doce River basins (Ref. 36801, 123859); R. Parahyba and tributaries at Mendez; Juiz de Fora; R. Doce; R. Sao Matheos; R. Jequitinhonha; R. Quenda at Santa Cruz (Ref. 26282); Glória (Paraíba do Sul River Basin), Itabapoana (Itabapoana River Basin) and Mucuri (Mucuri River Basin) rivers (Ref. 123859). + 
Anostomidae Hypomasticus despaxi (Puyo, 1943) Fr native  Piau (Portuguese)  16.00 cm TL male/unsexed  Present in the Oyapock River which forms the border between Brazil and French Guiana (Ref. 12225). Also Ref. 36801. + 
Anostomidae Hypomasticus julii (Santos, Jégu & Lima, 1996) Fr endemic   26.40 cm TL male/unsexed  Known from Xingu River basin (Ref. 36801). Type locality: Rio Xingu, Cachoeira Kaituka, Pará (Ref. 42606). + 
Anostomidae Hypomasticus lineomaculatus Birindelli, Peixoto, Wosiacki & Britski, 2013 Fr native   6.35 cm SL male/unsexed  Known from the Rio Paru and Rio Jari, two tributaries of the left margin of the lower Rio Amazonas in Pará (Ref. 94192). - 
Anostomidae Hypomasticus mormyrops (Steindachner, 1875) Fr native    21.20 cm SL male/unsexed  Known from Paraíba do Sul, Piabanha, and Doce River basins (Ref. 36801). Type locality: Río Parahyba and Río Piabanha, Brazil (Ref. 26282). + 
Anostomidae Hypomasticus pachycheilus (Britski, 1976) Fr native    22.40 cm SL male/unsexed  Known from the Aripuanã River basin (Ref. 36801). Museum: Rio Aripuana, Mato Grosso State, MZUSP 13074 (holotype of L. pachycheilus, 15.7 cm SL) (Ref. 27925). - 
Anostomidae Hypomasticus steindachneri (Eigenmann, 1907) Fr native  Acará pinima (Portuguese), Piau (Portuguese)  34.50 cm SL male/unsexed  Known from Jequitinhonha River basin (Ref. 598, 36801) and Tiririca Lake, Doce River Basin (Ref. 123859) . - 
Anostomidae Hypomasticus thayeri (Borodin, 1929) Fr, Thr native  Timburé (Portuguese), Piau (Portuguese), Timburé-beiçudo (Portuguese)    Confirmed distribution from Paraíba do Sul, Doce and Itapemirim rivers (Ref. 79515) and reported occurrence in Jequitinhonha River basin (Ref. 36801) indicates otherwise from recent investigation (Ref. 79515, 79881). Also Ref. 36801. Status of threat: Vulnerable (Ref. 79515). - 
Xenocyprididae Hypophthalmichthys molitrix (Valenciennes, 1844) Fr introduced  Carpa prateada (Portuguese)   120 cm TL male/unsexed    + 
Xenocyprididae Hypophthalmichthys nobilis (Richardson, 1845) Fr not established  Carpa-cabeça-grande (Portuguese)   146 cm SL male/unsexed  Has established in aquaculture through assisted/artificial reproduction (Ref. 1739). Reported from the Uruguay River (Ref. 79585). + 
Pimelodidae Hypophthalmus edentatus Spix & Agassiz, 1829 Fr, Br, Fi native  Mapará (Portuguese), Lalau (Portuguese), Lau-lau (Portuguese), Mandubi (Portuguese), Mapa-racuii (Portuguese), Mapara (Portuguese), Mapurá (Portuguese), Moça (Portuguese), Olho-de-gato (Portuguese)   57.50 cm TL male/unsexed 23.3 TL   + 
Pimelodidae Hypophthalmus fimbriatus Kner, 1858 Fr, Fi native  Mapará bico de pena (Portuguese)   46.50 cm TL male/unsexed  Type locality: Rio Negro. Found in fish markets in Santarém (Ref. 12202). + 
Pimelodidae Hypophthalmus marginatus Valenciennes, 1840 Fr, Fi native  Mapará (Portuguese), Mampará (Portuguese)   56.00 cm TL male/unsexed  Found in fish markets in Santarém (Ref. 12202). + 
Pimelodidae Hypophthalmus oremaculatus Nani & Fuster de Plaza, 1947 Fr native    Known from Puerto Gaboto in the Rio Paraná (Ref. 6868). - 
Hypopomidae Hypopomus artedi (Kaup, 1856) Fr native  Tuvira (Portuguese), Itui (Portuguese)  50.00 cm SL male/unsexed   + 
Loricariidae Hypoptopoma bianale Aquino & Schaefer, 2010 Fr native   5.37 cm TL female  Known from the Amazons (Ref. 84367). - 
Loricariidae Hypoptopoma brevirostratum Aquino & Schaefer, 2010 Fr native   5.06 cm TL male/unsexed   - 
Loricariidae Hypoptopoma elongatum Aquino & Schaefer, 2010 Fr native   10.20 cm TL male/unsexed  Type locality, Pará, Rio Tapajos, Itaituba, INPA 7240 (holotype of Hypoptopoma elongatum, 9.54 cm SL, female). Known from Lower Rio Tapajos and lower Rio Trombetas (Ref. 84367). - 
Loricariidae Hypoptopoma gulare Cope, 1878 Fr native    13.50 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36885). Type locality: Upper Amazon at Calderon, Brazil (Ref. 26282). + 
Loricariidae Hypoptopoma incognitum Aquino & Schaefer, 2010 Fr native    10.80 cm SL male/unsexed  Known from Acre, Amazonas, Goiás, Maranhão, Mato Grosso, Rondonia and Roraima (Ref. 84367). - 
Loricariidae Hypoptopoma inexspectatum (Holmberg, 1893) Fr native    7.10 cm SL male/unsexed  Type locality, Descalvados, Mato Grosso (holotype of Hypoptopoma guentheri). Known from Mato Grosso and Mato Grosso do Sul; no records for the upper Paraná upstream of Salto das Sete Quedas (Mato Grosso do Sul, Brazil) (Ref. 84367). + 
Loricariidae Hypoptopoma muzuspi Aquino & Schaefer, 2010 Fr native   3.63 cm male/unsexed  Tocantins State, Araguaçu, rio Agua Fria, fazenda Praia Alta 2, estrada Araguaçu/Barreira do Piqui, 27 km ao norte de Araguaçu, MZUSP 52135 (holotyep of Hypoptopoma muzuspi, 3.63 cm SL, male) (Ref. 84367). - 
Loricariidae Hypoptopoma steindachneri Boulenger, 1895 Fr native    10.00 cm SL male/unsexed  Found in the Amazon River (Ref. 36885). Also Ref. 84367. + 
Loricariidae Hypoptopoma thoracatum Günther, 1868 Fr native    11.50 cm TL male/unsexed  Found in the Amazon (Ref. 36885). Purus and Acre River basins (Ref. 97592). + 
Hypopomidae Hypopygus benoneae Peixoto, Dutra, de Santana & Wosicki, 2013 Fr native   9.21 cm TL male/unsexed  Found in the rainforest streams in the lower Rio Anapu in the Floresta Nacional de Caxiuanã, lower Amazon basin, Pará (Ref. 93869). - 
Hypopomidae Hypopygus hoedemani de Santana & Crampton, 2011 Fr native   5.92 cm TL male/unsexed   - 
Hypopomidae Hypopygus isbruckeri de Santana & Crampton, 2011 Fr native   9.00 cm TL male/unsexed   - 
Hypopomidae Hypopygus lepturus Hoedeman, 1962 Fr native  Itui (Portuguese), Tuvira (Portuguese)   10.00 cm TL male/unsexed  Widespread in the Amazon (Ref. 12225). Recorded from Machado (Ref. 97589) and Acre River basin (Ref. 97592). - 
Hypopomidae Hypopygus nijsseni de Santana & Crampton, 2011 Fr native   9.60 cm TL male/unsexed   - 
Hypopomidae Hypopygus varii Campos-da-Paz, 2018 Fr native    Type locality from holotype of Hypopygus varii, garapé Saracá, Oriximiná, rio Trombetas drainage, Amazon basin, Pará, Brazil (Ref. 128475). - 
Hemiramphidae Hyporhamphus brederi (Fernández-Yépez, 1948) Fr native   10.00 cm SL male/unsexed  Known from the Amazon River at Santarem (Ref. 40614). - 
Loricariidae Hypostomus affinis (Steindachner, 1877) Fr native    39.70 cm SL male/unsexed  Type locality: Campos (21°50'S, 41°20'W), Rio Paríba do Sul, State of Rio de Janeiro, Brazil (Ref. 26282). + 
Loricariidae Hypostomus agna (Miranda Ribeiro, 1907) Fr native  Anhá (Portuguese), Anhã (Portuguese), Mãe de anhá (Portuguese), Mãe de anhã (Portuguese)   22.00 cm TL male/unsexed  Type locality: Rio Ribeira, affluent of the Iporanga, Sao Paulo (Ref. 6868). - 
Loricariidae Hypostomus alatus Castelnau, 1855 Fr native  Acari (Portuguese), Cascudo (Portuguese), Cascudo chitão (Portuguese)   28.79 cm SL male/unsexed  Type locality: Rio Sabara, Minas Gerais Prov., Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus albopunctatus (Regan, 1908) Fr native  Cascudo ferro (Portuguese), Cascudo (Portuguese), Cascudo preto (Portuguese)   40.00 cm SL male/unsexed  Found in rio Paraná-Paraguay basin including rio Iguaçu (Ref. 91066). Type locality: Rio Piracicaba, Sao Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus ancistroides (Ihering, 1911) Fr native  Cascudo bugio (Portuguese), Cascudo pintado (Portuguese)   21.00 cm TL male/unsexed  Occurs in the Pardo River, upper Paraná River basin, southeastern Brazil (Ref. 27745). Recorded from Córrego Barreiro (Ref. 53011). Type locality: Rio Tatuhy and Rio Piracicaba, Est. de S. Paulo, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus angipinnatus (Leege, 1922) Fr native   15.00 cm male/unsexed  Type locality: Mato Grosso, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus asperatus Castelnau, 1855 Fr native   22.90 cm SL male/unsexed  Type locality: Rio Araguay, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus aspilogaster (Cope, 1894) Fr native   26.50 cm SL male/unsexed  Type locality: Rio Jacuhy, Rio Grande do Sul, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus atropinnis (Eigenmann & Eigenmann, 1890) Fr native   21.00 cm TL male/unsexed  Type locality: Goiás, Brazil (Ref. 26282). - 
Loricariidae Hypostomus auroguttatus Kner, 1854 Fr native  Cascudo (Portuguese)   34.00 cm TL male/unsexed  Type locality not explicitly given, restricted to Rio Parahyba (syntype not found in NMW). Museum: Im Rio. Parahyba , River Mucuri, River San Antonio, River Quenda, River de Pedra [restricted to rio Paraíba do Sul and tributaries, State of Rio de Janeiro], NMW 44196 (lectotype of Plecostomus luetkeni) (Ref. 6868, 26282). - 
Loricariidae Hypostomus basilisko Tencatt, Zawadzki & Froehlich, 2014 Fr native    19.78 cm SL male/unsexed  Known from the rio Salobra basin of the rio Paraguay basin, Bodoquena Plateau in Mato Grosso do Sul (Ref. 97225). + 
Loricariidae Hypostomus bimbai Zawadzki & Penido, 2021 Fr native   31.35 cm SL male/unsexed  Type locality of Hypostomus bimbai, Bahia State: Paulo Afonso, channel of Rio São Francisco, Known from main channel of the Rio São Francisco downstream of Paulo Afonso IV dam, at the border of Bahia and Alagoas States (Ref. 124776). - 
Loricariidae Hypostomus boulengeri (Eigenmann & Kennedy, 1903) Fr native  Cascudo (Portuguese)  24.50 cm SL male/unsexed   + 
Loricariidae Hypostomus brevicauda (Günther, 1864) Fr native   19.61 cm SL male/unsexed  Type locality: Bahia, Brazil (Ref. 6868). - 
Loricariidae Hypostomus brevis (Nichols, 1919) Fr native   7.40 cm SL male/unsexed  Type locality: State of Sao Paulo (Ref. 26282, 6868). - 
Loricariidae Hypostomus careopinnatus Martins, Marinho, Langeani & Serra, 2012 Fr native   5.79 cm SL male/unsexed  Known from Rio Taquari drainage, upper Rio Paraguay basin , Alto Araguaia in Mato Grosso State (Ref. 91756). - 
Loricariidae Hypostomus carinatus (Steindachner, 1881) Fr native   24.80 cm SL male/unsexed   - 
Loricariidae Hypostomus carvalhoi (Miranda Ribeiro, 1937) Fr native  Cascudo (Portuguese)  14.20 cm SL male/unsexed  Type locality: Rio Granjeiro, Crato, Ceará, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus chrysostiktos Birindelli, Zanata & Lima, 2007 Fr native   25.97 cm SL male/unsexed  Widespread and found only in rio Paraguaçu basin, an independent coastal drainage in northeastern Brazil (Ref. 75060). - 
Loricariidae Hypostomus cochliodon Kner, 1854 Fr native  Cascudo (Portuguese)   23.00 cm SL male/unsexed  Recorded from Pantanal (Ref. 81048). Found in Rio Cujaba (Ref. 6868). Also Ref. 36817. + 
Loricariidae Hypostomus commersoni Valenciennes, 1836 Fr native  Coroncho (Portuguese), Acari (Portuguese), Acarí (Portuguese), Bacu puá (Portuguese), Camboatá (Portuguese), Cascudo (Portuguese), Cascudo asa branca (Portuguese), Cascudo cachichô (Portuguese), Cascudo cinzento (Portuguese), Cascudo comum (Portuguese), Cascudo panaque (Portuguese), Cascudo prêto (Portuguese), Cascudo trepa pau (Portuguese), Cascudo-chocolate (Portuguese), Guacarí (Portuguese), Iarú urá (Portuguese), Jaruitaquara (Portuguese), Pirá tatu (Portuguese), Uacarí (Portuguese), Uará urá (Portuguese), Vieja (Portuguese), Yaru itacura (Portuguese)   60.50 cm TL male/unsexed  Known from Saint-Francois River (Ref. 36817). Also recorded from the Patos lagoon (Ref. 58359) and Uruguay River (Ref. 79585). Also Ref. 6868. + 
Loricariidae Hypostomus dardanelos Zawadzki & Carvalho, 2014 Fr native   18.39 cm SL male/unsexed  Found in the rio Aripuanã drainage, downstream cachoeira Dardanelos (Ref. 95498). - 
Loricariidae Hypostomus delimai Zawadzki, de Oliveira & Debona, 2013 Fr native   25.31 cm SL male/unsexed  Known only from the middle stretches of the rio Tocantins-Araguaia basin (Ref. 93220). - 
Loricariidae Hypostomus denticulatus Zawadzki, Weber & Pavanelli, 2008 Fr native   19.13 cm SL male/unsexed  Known from the rio Corumbá in the vicinity of the Corumbá Reservoir of the upper rio Paraná basin, mostly collected in the reservoir of the rio Corumbá just upstream from the dam and its tributary the rio Areia (Ref. 79067). - 
Loricariidae Hypostomus derbyi (Haseman, 1911) Fr native  Cascudo (Portuguese)   31.00 cm SL male/unsexed  Type locality: Rio Iguaçu at Porto Uniao da Victoria, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus eptingi (Fowler, 1941) Fr native   12.20 cm SL male/unsexed  Known from Fortaleza, Ceara (Ref. 6868). - 
Loricariidae Hypostomus ericae Hollanda Carvalho & Weber, 2005 Fr native   28.50 cm SL male/unsexed ;24.00 cm SL female  Known from the upper Tocantins River drainage in Goiás, on the region of influence of the Serra da Mesa dam (Ref. 56681). - 
Loricariidae Hypostomus faveolus Zawadzki, Birindelli & Lima, 2008 Fr native   20.60 cm SL male/unsexed  Known from several localities in the rio Tocantins basin and the upper rio Xingu basin in central Brazil. A single record from the rio Meia, Ponte, a tributary of rio Paranaíba, upper rio Paraná drainage in central Brazil likely represents an unnatural occurrence as it is a common practice among recreational fishermen and ranchers from Goiânia area (capital of Goiás state) to release fishes from the rio Araguaia basin in artificial ponds in the rio Meia Ponte catchment area (Ref. 79072). + 
Loricariidae Hypostomus fluviatilis (Schubart, 1964) Fr native  Cascudo (Portuguese)   16.50 cm SL male/unsexed  Type locality: Rio Mogi Guaçu basin (Ref. 26282, 6868). - 
Loricariidae Hypostomus francisci (Lütken, 1874) Fr native  Acari (Portuguese), Cascudo (Portuguese)   36.00 cm SL male/unsexed  Type locality: Rio San Francisco (Ref. 26282, 6868). - 
Loricariidae Hypostomus garmani (Regan, 1904) Fr native  Cascudo (Portuguese)  13.02 cm SL male/unsexed  Type locality: Rio das Velhas, eastern Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus goyazensis (Regan, 1908) Fr native   26.00 cm TL male/unsexed  Type locality: Goiás, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus hemicochliodon Armbruster, 2003 Fr native   36.20 cm TL male/unsexed  Known from the Rios Tapajos and Xingu of the lower Rio Amazonas drainage (Ref. 50589). + 
Loricariidae Hypostomus heraldoi Zawadzki, Weber & Pavanelli, 2008 Fr native   23.61 cm SL male/unsexed  Found in the Rio Corumbá and rio Grande drainages of the upper rio Paraná basin. This species was mainly collected from the Corumbá Reservoir and its tributary rio Pirapitinga (Ref. 79067). - 
Loricariidae Hypostomus hermanni (Ihering, 1905) Fr native  Cascudo comum (Portuguese), Cascudo pintado (Portuguese)   24.00 cm TL male/unsexed  Type locality of Hypostomus hermanni, Rio Piracicaba, Sao Paulo (Ref. 6868). Known from southeastern Brazil (São Paulo, Piracicaba River and Tietê River basin) and southern Brazil (Paraná, Paraná River main channel and three of its left tributaries, Paranapanema, Ivaí, and Piquiri basin) (Ref. 124595). - 
Loricariidae Hypostomus hoplonites Rapp Py-Daniel, 1988 Fr native    32.50 cm SL male/unsexed    - 
Loricariidae Hypostomus iheringii (Regan, 1908) Fr native   11.60 cm SL male/unsexed  Type locality: Rio Piracicaba, San Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus interruptus (Miranda Ribeiro, 1918) Fr native   12.00 cm SL male/unsexed  Type locality: Rio Juquiá, Poço Grande, Estado de Sao Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus isbrueckeri Reis, Weber & Malabarba, 1990 Fr native  Cascudo (Portuguese)  30.80 cm TL male/unsexed  Known from the Uruguay River basin (Ref. 36817). Type locality: Rio Conceição, Ijui, Rio Grande do Sul, Brazil (Ref. 26282). - 
Loricariidae Hypostomus itacua Valenciennes, 1836 Fr questionable   11.00 cm TL male/unsexed   - 
Loricariidae Hypostomus jaguar Zanata, Sardeiro & Zawadzki, 2013 Fr native  Acari (Portuguese), Aacari-preto (Portuguese), Acari-pintado (Portuguese)  17.56 cm SL male/unsexed  Found in rio Paraguaçu basin, an independent coastal drainage in northeastern Brazil situated on the eastern slopes of the Chapada Diamantina, Bahia State (Ref. 93813). - 
Loricariidae Hypostomus jaguribensis (Fowler, 1915) Fr native  Cascudo (Portuguese)   12.00 cm TL male/unsexed  Type locality: Rio Jaguribe at Barrio Alto, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus johnii (Steindachner, 1877) Fr native   11.30 cm SL male/unsexed  Type locality: Rio Puty and Rio Preto, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus khimaera Tencatt, Zawadzki & Froehlich, 2014 Fr native   16.38 cm SL male/unsexed  Found in several localities of rio Paraguay basin, such as rios Cuiabá, Manso, Quilombo, Coxipó, Coxim, baía de Chacororé, rios Vermelho and Aquidauana basins (Ref. 97225). - 
Loricariidae Hypostomus kopeyaka Carvalho, Lima & Zawadzki, 2010 Fr native   22.61 cm SL male/unsexed   - 
Loricariidae Hypostomus kuarup Zawadzki, Birindelli & Lima, 2012 Fr native   21.77 cm SL male/unsexed  Known from the rio Culuene, upper rio Xingu basin in Mato Grosso (Ref. 91068). - 
Loricariidae Hypostomus laplatae (Eigenmann, 1907) Fr native   69.00 cm TL male/unsexed  Type locality: Near Rio De Janeiro (Ref. 26282, 6868). + 
Loricariidae Hypostomus latirostris (Regan, 1904) Fr native   26.00 cm TL male/unsexed  Type locality: Rio Jungada, Mato Grosso and Goiás, Brazil (Ref. 6868). - 
Loricariidae Hypostomus leucophaeus Zanata & Pitanga, 2016 Fr native   15.82 cm SL male/unsexed  Known from rio Itapicuru basin, a drainage located in the northern portion of the Bahia State. Captured mainly in the upper and lower portions of the basin. Anthropic activities such as construction of water reservoirs for cattle and human use have impacted most of the sampling areas (Ref. 110236). - 
Loricariidae Hypostomus lexi (Ihering, 1911) Fr native   46.00 cm SL male/unsexed  Type locality: Rio Pardo, perto de Barretos, Estado de Sao Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus lima (Lütken, 1874) Fr native  Cascudo (Portuguese)   13.62 cm SL male/unsexed  Type locality: Rio das Velhas, Ribeirao do Mato and Lagoa Santa, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus longiradiatus (Holly, 1929) Fr native   39.50 cm TL male/unsexed  Type locality: Rio Guaná, assumably a trib. of the Madeira, itself a trib. of the Amazon, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus luetkeni (Steindachner, 1877) Fr native    25.40 cm SL male/unsexed  Type locality, Rio Parahyba, Rio Mucuri, Rio San Antonio, Rio Quenda, Rio de Pedra (restricted to rio Paraíba do Sul and tributaries), State of Rio de Janeiro (Ref. 36817). + 
Loricariidae Hypostomus luteomaculatus (Devincenzi, 1942) Fr native  Cascudo amarelo (Portuguese), Cascudo chita (Portuguese), Chitão (Portuguese)  28.00 cm SL male/unsexed   - 
Loricariidae Hypostomus luteus (Godoy, 1980) Fr native  Cascudo-amarelo (Portuguese), Cascudo-pintado (Portuguese)  40.50 cm TL male/unsexed  Known from the Uruguay River (Ref. 79585). Type locality: Rio Pelotas at Volta Grande Dois, Marcelino Ramos, Rio Grande do Sul, Brazil (Ref. 26282). + 
Loricariidae Hypostomus macrops (Eigenmann & Eigenmann, 1888) Fr native  Cascudo (Portuguese)  28.80 cm SL male/unsexed  Type locality: Rio das Velhas, Minas Gerais, Brazil (Ref. 26282). - 
Loricariidae Hypostomus margaritifer (Regan, 1908) Fr, Fi native  Cascudo pintado (Portuguese)   33.00 cm TL male/unsexed  Found in Piracicaba river (Ref. 50076). Type locality: Rio Piracicaba, San Paulo, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus melanephelis Zawadzki, Oliveira, Oliveira & Py-Daniel, 2015 Fr endemic    17.80 cm SL male/unsexed  Currently known only from the rio Tapajós basin, near Itaituba city, Pará State, Brazil (Ref. 103391). - 
Loricariidae Hypostomus meleagris (Marini, Nichols & La Monte, 1933) Fr native    30.00 cm SL male/unsexed  Type locality: Southeastern Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus microstomus Weber, 1987 Fr native    24.00 cm SL male/unsexed   - 
Loricariidae Hypostomus multidens Jerep, Shibatta & Zawadzki, 2007 Fr native   19.75 cm SL male/unsexed  Found in several localities of the rio Paranapanema basin in São Paulo and Paraná. Also encountered in the rio Paraná in the transition from rapid to still waters at the beginning of the Itaipú Reservoir lake in the city of Guaíra (Ref. 75037). - 
Loricariidae Hypostomus mutucae Knaack, 1999 Fr native   10.92 cm SL male/unsexed  Known from Cuiabá River basin (Ref. 36817). + 
Loricariidae Hypostomus myersi (Gosline, 1947) Fr, Fi native  Cascudo (Portuguese)   20.70 cm SL male/unsexed  Found in Piracicaba river (Ref. 50076). Type locality: Rio Iguaçu at Porto Uniao, Paraná, s. Brazil (Ref. 26282, 6868. - 
Loricariidae Hypostomus niger (Marini, Nichols & La Monte, 1933) Fr native   24.50 cm SL male/unsexed  Type locality: Southeastern Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus nigromaculatus (Schubart, 1964) Fr native    10.20 cm SL male/unsexed  Type locality: Cachoeira de Emas, Rio Mogi Guassu basin, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus nigropunctatus Garavello, Britski & Zawadzki, 2012 Fr native   23.29 cm SL male/unsexed  Found in rio Iguaçu, Paraná State. Occurs in the middle stretches of the rio Iguaçu, at Salto Segredo reservoir and at the mouth of rios Covó and Jordão (Ref. 91066). - 
Loricariidae Hypostomus nudiventris (Fowler, 1941) Fr native  Cascudo (Portuguese)  5.70 cm SL male/unsexed  Type locality: Rio Choró, Ceará, near Fortaleza, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus obtusirostris (Steindachner, 1907) Fr native  Cascudo (Portuguese)  5.90 cm TL male/unsexed  Type locality: Rio Cubatao, Santa Catherina by Theresopolis, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus pantherinus Kner, 1854 Fr native   4.80 cm SL male/unsexed  Type locality: Rio Guaporé, Upper Amazon, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus papariae (Fowler, 1941) Fr native  Cascudo (Portuguese)  11.40 cm TL male/unsexed  Type locality: Lago Papary, Rio Grande do Norte, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus pastinhai Zawadzki & Penido, 2021 Fr native   25.08 cm SL male/unsexed  Type locality of Hypostomus pastinhai, Bahia State: Paulo Afonso, channel of Rio São Francisco. Known from main channel of the Rio São Francisco downstream of Paulo Afonso IV dam, at the border of Bahia and Alagoas States (Ref. 124776). - 
Loricariidae Hypostomus paucipunctatus Hollanda Carvalho & Weber, 2005 Fr native   18.80 cm SL male/unsexed  Known from Rio Itacaiúnas drainage, Serra dos Carajás, Pará (Ref. 56681). Recorded from the lower Rio Tocantins basin (Ref. 85327). - 
Loricariidae Hypostomus paulinus (Ihering, 1905) Fr native  Cascudo preto (Portuguese)   13.50 cm SL male/unsexed  Type locality: Rio Piracicaba, Sao Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus peckoltoides Zawadzki, Weber & Pavanelli, 2010 Fr native   11.07 cm SL male/unsexed  Type locality, Mato Grosso State, Municipality of Santo Antônio do Leverger, rio Cuiabá, upper rio Paraguay basin, MZUSP 105226 (holotype of Hypostomus peckoltoides, 11.07 cm SL). Knowm from its type locality, rio Cuiabá, upper rio Paraguay basin (Ref. 85849). - 
Loricariidae Hypostomus perdido Zawadzki, Tencatt & Froehlich, 2014 Fr native   18.10 cm SL male/unsexed  Known from the rio Perdido, tributary to the rio Apa, rio Paraguai basin, Mato Grosso do Sul State (Ref. 95502). - 
Loricariidae Hypostomus plecostomus (Linnaeus, 1758) Fr, Fi native  Acari (Portuguese), Acarí (Portuguese), Acarí pedral (Portuguese), Acari-bodó (Portuguese), Armadilho (Portuguese), Bode (Portuguese), Bode de Igarapé (Portuguese), Bodó (Portuguese), Cascudo (Portuguese), Guacari (Portuguese), Guacarí (Portuguese), Pirá tatu (Portuguese), Vacarí (Portuguese), Yau urá (Portuguese)   24.98 cm SL male/unsexed  Found in Piracicaba river (Ref. 50076). + 
Loricariidae Hypostomus punctatus Valenciennes, 1840 Fr native  Cascudo (Portuguese), Camboatá (Portuguese), Cascudo chinelo (Portuguese)  30.00 cm TL male/unsexed  Type locality: Rio de Janeiro (Ref. 26282, 6868). + 
Loricariidae Hypostomus pusarum (Starks, 1913) Fr native  Cascudo (Portuguese)   20.30 cm TL male/unsexed  Type locality: Ceará, Mirim, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus pyrineusi (Miranda Ribeiro, 1920) Fr native    26.00 cm TL male/unsexed  Recorded from Machado river basin (Ref. 97589). Type locality: Jamary, Rio Madeira, Amazon system, Brazil (Ref. 26282). - 
Loricariidae Hypostomus regani (Ihering, 1905) Fr native  Cascudo-chita (Portuguese), Cascudo (Portuguese), Cascudo barata (Portuguese), Cascudo-chitão (Portuguese), Cascudo-pintado (Portuguese), Chitão (Portuguese)   41.00 cm SL male/unsexed  Known from the Uruguay River (Ref. 79585). Type locality: Rio Piracicaba, Sao Paulo, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus robertsoni Dias & Zawadzki, 2021 Fr native   13.57 cm SL male/unsexed  Type locality of Hypostomus robertsoni, Paraná State, Município de Marialva, Upper Paraná River basin, tributary of Ivaí River, Keller River. This Ivaí River basin can be geographically divided into three portions: upper portion with steep slopes ranging from about 1200 to 600 m a.s.l. is a high gradient system; from this section, the median portion goes down to about 400 m a.s.l. having strong to moderate declivities; the lower section is marked by a very low declivity. This species occurs syntopically with H. hermanni in this basin, but while H. hermanni is most frequently captured in the Ivaí River main channel, H. robertsoni commonly occurs either in the Ivaí River and in smaller tributaries (Ref. 124595). Status of threat: This species is not abundant in scientific collections and does not present a wide distribution in the Upper Paraná River basin. Presently found only in the Ivaí basin, however it is possible that it occurs in adjacent basins and since there are no known imminent threats that would put the species at risk of extinction, this species may be categorized as Least Concern (LC), according to the International Union for Conservation of Nature (IUCN) categories and criteria (IUCN Standards and Petitions Subcommittee, 2019). - 
Loricariidae Hypostomus rondoni (Miranda Ribeiro, 1912) Fr native   8.00 cm TL male/unsexed  Type locality: Rio Tapajós at Sao Manuel, Mato Grosso, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus roseopunctatus Reis, Weber & Malabarba, 1990 Fr native  Cascudo (Portuguese)  43.30 cm TL male/unsexed  Known from the Uruguay River (Ref. 79585). Type locality: Rio Pelotas at road from Esmeralda to Anita Garibaldi, Rio Grande do Sul, Brazil (Ref. 26282). - 
Loricariidae Hypostomus salgadae (Fowler, 1941) Fr endemic   2.00 cm SL male/unsexed  Known from the Jaguaribe River basin (Ref. 48602). Recorded from Rio Salgade, Ico (Ref. 6868). - 
Loricariidae Hypostomus scabriceps (Eigenmann & Eigenmann, 1888) Fr native  Acarí (Portuguese), Bacu puá (Portuguese), Cascudo (Portuguese), Cascudo cachichô (Portuguese), Cascudo comum (Portuguese), Cascudo prêto (Portuguese), Guacarí (Portuguese), Iarú urá (Portuguese), Jaru itaquara (Portuguese), Jaruitacoara (Portuguese), Pirá tatu (Portuguese), Uacarí (Portuguese), Uará urá (Portuguese), Yaru itacura (Portuguese)   35.00 cm TL male/unsexed  Type locality: Sao Matheus, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus scaphyceps (Nichols, 1919) Fr native   3.50 cm SL male/unsexed  Type locality: Cerqueira Cezar, Estado de Sao Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus seminudus (Eigenmann & Eigenmann, 1888) Fr native    Type locality: Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus simios Hollanda Carvalho & Weber, 2005 Fr native   15.79 cm SL male/unsexed  Known only from its type locality, Cupixi River in Amapá (Ref. 56681). - 
Loricariidae Hypostomus soniae Hollanda Carvalho & Weber, 2005 Fr native   16.37 cm SL male/unsexed  Known from Tapajós River in Pará (Ref. 56681). + 
Loricariidae Hypostomus spiniger (Hensel, 1870) Fr native   28.30 cm SL male/unsexed  Type locality of Plecostomus spiniger Rio Cadea (=Cadeia River), Rio Grande do Sul and of Plecostomus limosus Rio Grande do Sul (lectotype MCZ 7869) (Ref. 121236). - 
Loricariidae Hypostomus strigaticeps (Regan, 1908) Fr native  Cascudo pintado (Portuguese)   16.00 cm SL male/unsexed  Type locality: Rio Piracicaba, San Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus subcarinatus Castelnau, 1855 Fr native   31.00 cm TL male/unsexed  Type locality: Minas Gerais Prov., Brazil (Ref. 26282). + 
Loricariidae Hypostomus tapijara Oyakawa, Akama & Zanata, 2005 Fr native   37.83 cm SL male/unsexed  Known from Rio Ribeira de Iguape drainage in São Paulo and Paraná States (Ref. 54480). - 
Loricariidae Hypostomus ternetzi (Boulenger, 1895) Fr native  Cascudo (Portuguese)   34.30 cm TL male/unsexed  Known from the Uruguay River (Ref. 79585). + 
Loricariidae Hypostomus tietensis (Ihering, 1905) Fr native   12.50 cm SL male/unsexed  Type locality: Rio Tieté, Sao Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus topavae (Godoy, 1969) Fr native    70.00 cm SL male/unsexed  Type locality: Cachoeira de Emas, Rio Mogi Guassu, Sao Paulo State, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus unae (Steindachner, 1878) Fr native  Cascudo (Portuguese)  18.30 cm SL male/unsexed  Type locality: Rio Una, Brazil (Ref. 26282, 6868). + 
Loricariidae Hypostomus uruguayensis Reis, Weber & Malabarba, 1990 Fr native  Cascudo (Portuguese)  34.50 cm TL male/unsexed  Known from the Uruguay River (Ref. 79585). Type locality: Rio Uruguay at "Rancho da Amizade", São Borja, Rio Grande do Sul, Brazil (Ref. 26282). - 
Loricariidae Hypostomus vaillanti (Steindachner, 1877) Fr native  Cascudo (Portuguese)  18.50 cm SL male/unsexed  Type locality: Rio Preto at Villa de Santa Rita, Bahia, Brazil (Ref. 26282, 6868). - 
Loricariidae Hypostomus variipictus (Ihering, 1911) Fr native  Cascudo (Portuguese)   37.00 cm TL male/unsexed  Found in Rio Pardo de Barretos, São Paulo (Ref. 6868). + 
Loricariidae Hypostomus varimaculosus (Fowler, 1945) Fr native   6.00 cm SL male/unsexed   - 
Loricariidae Hypostomus variostictus (Miranda Ribeiro, 1912) Fr native   5.70 cm TL male/unsexed  Found in Coxim, Mato Grosso (Ref. 6868). - 
Loricariidae Hypostomus velhochico Zawadzki, Oyakawa & Britski, 2017 Fr native   13.88 cm SL male/unsexed  Type locality of Hypostomus velhochio from municipality of São João das Missões, unknown name stream, tributary of rio Itacarambi, Brazil, MZUSP 47327. Also from tributaries in these states Minas Gerais, Distrito Federal, Bahia (Ref. 128916). - 
Loricariidae Hypostomus vermicularis (Eigenmann & Eigenmann, 1888) Fr native   19.00 cm SL male/unsexed  Known from Rio Parahyba, Rio Janeiro, Mendez, Macacos, Goyaz (Ref. 6868). - 
Loricariidae Hypostomus waiampi Hollanda Carvalho & Weber, 2005 Fr native   19.39 cm SL male/unsexed  Found only in its type locality, the Cupixi River, State of Amapá (Ref. 56681). - 
Loricariidae Hypostomus watwata Hancock, 1828 Fr native  Acari (Portuguese), Acari do mar (Portuguese), Caraboï (Portuguese)   45.00 cm SL male/unsexed    + 
Loricariidae Hypostomus weberi Carvalho, Lima & Zawadzki, 2010 Fr native   17.45 cm SL male/unsexed  Foundin the middle rio Negro area at Barcelos and its tributary, the rio Marauiá (Ref. 83896). - 
Loricariidae Hypostomus wuchereri (Günther, 1864) Fr native  Cascudo (Portuguese)  35.00 cm SL male/unsexed  Found in Bahia (Ref. 6868). - 
Loricariidae Hypostomus yaku Martins, Langeani & Zawadzki, 2014 Fr native   7.08 cm SL male/unsexed  Found in the rio Quente, a small tributary of rio Piracanjuba, rio Paranaíba drainage, upper rio Paraná basin in central Brazil. Although very abundant in the type locality, this restricted occurrence to areas with anthropic influence (e.g., urban expansion, tourism, organic pollution) requires special attention for conservation with frequent monitoring of the populations of this species (Ref. 97842). - 
Cichlidae Hypselecara coryphaenoides (Heckel, 1840) Fr native  Acarra pixuna (Portuguese)  16.00 cm SL male/unsexed  Known from the Amazon River basin in the Negro, Trombetas, Tapajós, Maués and Uatumã rivers (Ref. 36377). Common in the Río Negro (Ref. 12251). + 
Cichlidae Hypselecara temporalis (Günther, 1862) Fr native  Acará açai (Portuguese), Acará (Portuguese), Acará-açaí (Portuguese), Cará (Portuguese), Cará de lago (Portuguese)   15.00 cm SL male/unsexed  Found in the Solimôes-Amazon River, Oyapock River basin, and rivers of Amapá State (Ref. 36377). Also Ref. 9088, 35237. + 
Rivulidae Hypsolebias adornatus (Costa, 2000) Fr native   4.51 cm SL male/unsexed ;3.95 cm SL female  Occurs in the rio São Francisco basin, NE Brazil. Type locality, Estado da Bahia (Ref. 44211). Also Ref. 36579. + 
Rivulidae Hypsolebias antenori (Tulipano, 1973) Fr endemic    7.00 cm TL male/unsexed  Known from the lower section of the rio Jaguaribe basin, and smaller coastal adjacent basins between Mecejana, Estado do Ceará, and Areia Branca, Estado do Río Grande do Norte (Ref. 49550). Also Ref. 27139, 36579. + 
Rivulidae Hypsolebias auratus (Costa & Nielsen, 2000) Fr native    5.00 cm TL male/unsexed  Type locality, temporary pool close to rio Taboca, a tributary of rio Paracatu, rio São Francisco basin, Lagoa Grande, Minas Gerais. + 
Rivulidae Hypsolebias brunoi (Costa, 2003) Fr endemic   3.01 cm SL male/unsexed  Known only from the type locality, temporary pool near the city of Vila Boa, ribeirão Canabrava floodplains, upper rio Urucuia drainage, rio São Francisco basin (Ref. 49550). - 
Rivulidae Hypsolebias caeruleus Costa, 2013 Fr native    Known from Rio São Francisco (Ref. 111470). - 
Rivulidae Hypsolebias carlettoi (Costa & Nielsen, 2004) Fr native    Type locality, Temporary pool near Guanambi, off the road to Malhada, 14°13.989'S, 42°57.667'W, Estado da Bahia, elev. 500 m (Ref. 54621). + 
Rivulidae Hypsolebias coamazonicus Costa, Amorim & Bragança, 2014 Fr native   3.64 cm SL male/unsexed ;2.78 cm SL female  Found in a temporary pool in the floodplains of the lower Parnaíba River, close to the road between Pirangi and Araioses, Maranhão in northeastern Brazil (Ref. 94133). - 
Rivulidae Hypsolebias faouri Britzke, Nielsen & Oliveira, 2016 Fr native   4.46 cm SL male/unsexed ;3.95 cm SL female  Type locality of Hypsolebias faouri: Rio Preto, Rio São Francisco basin, Bahia State (Ref. 108434). - 
Rivulidae Hypsolebias flagellatus (Costa, 2003) Fr native   5.13 cm SL male/unsexed  Known from the floodplains of middle São Francisco and two main tributaries (Correntes and Verde), between Boa Vista do Lagamar (Bahia) and São Francisco (Minas Gerais) (Ref. 49550). Intensive collecting efforts in May 2009 found a single specimen in a second locality, about 35 km N distant from the first one, about 1.5 km from the São Francisco River bank (Ref. 89836). + 
Rivulidae Hypsolebias flammeus (Costa, 1989) Fr native    6.00 cm TL male/unsexed  Known from the middle rio Tocantins basin between Nova Roma, Goiás, and Peixe, Tocantins (Ref. 49550). Also Ref. 27139, 36579. + 
Rivulidae Hypsolebias flavicaudatus (Costa & Brasil, 1990) Fr, Thr endemic   8.00 cm TL male/unsexed  Known from middle rio São Francisco basin, between Irecê, Bahia and Santa Maria da Boa Vista, Pernambuco, NE Brazil (Ref. 49550). Considered cirically endangered due to small area of occupancy associated with the strong decline in quality of the habitat and abrupt reduction in subpopulations (Ref. 89836). Also Ref. 27139, 36579. + 
Rivulidae Hypsolebias fulminantis (Costa & Brasil, 1993) Fr endemic    6.00 cm TL male/unsexed  Known from the middle São Francisco River basin (Ref. 36579). Museum: swamp near Guanambi, Estado da Bahia, MZUSP 43674 (holotype of S. fulminantis) (Ref. 36579). + 
Rivulidae Hypsolebias gardneri Costa, Amorim & Mattos, 2018 Fr native   3.69 cm SL male/unsexed ;3.00 cm SL female  Type locality of Hypsolebias gardneri, temporary pool in São Francisco River floodplains, Bahia (Ref. 128003). - 
Rivulidae Hypsolebias ghisolfii (Costa, Cyrino & Nielsen, 1996) Fr endemic    7.28 cm SL male/unsexed  Known from the São Francisco River basin (Ref. 36579). Type locality, Guanambi, Bahia, Brazil (Ref. 49550). + 
Rivulidae Hypsolebias gilbertobrasili Costa, 2012 Fr native  scarce (very unlikely) 3.74 cm SL male/unsexed ;3.38 cm SL female  Known only from a seasonal swamp, middle São Francisco River basin in Município de Bom Jesus da Lapa, Estado da Bahia. The swamp consists of shallow channels within a savannah forest, situated in a shallow depression running perpendicular to the São Francisco River. The depression extends to the west towards the São Francisco River, where the area is intensively deforested and to the east by about 4.5 km within swampy savannah forest. Considered a rare and vulnerable species due to its small area of ocuurence (Ref. 89836). - 
Rivulidae Hypsolebias guanambi Costa & Amorim, 2011 Fr, Thr native   3.92 cm SL male/unsexed  Found only in some seasonal pools adjacent to a small stream tributary to the Carnaíba de Dentro River, which is a right tributary of the São Francisco River, 13 km W of Guanambi, Bahia (Ref. 87364). Considered a critically endangered species due to rapid decline in the extent of occurrence and quality of habitat (Ref. 89836). - 
Rivulidae Hypsolebias hamadryades Costa, Amorim & Mattos, 2018 Fr native   2.69 cm SL male/unsexed ;2.37 cm SL female  Type locality of Hypsolebias hamadryades, temporary pool in the floodplains of the Gorutuba River, São Francisco River basin, Minas Gerais (Ref. 128003). - 
Rivulidae Hypsolebias harmonicus (Costa, 2010) Fr native    Known from the middle São Francisco River in northeastern Brazil (Ref. 84055). - 
Rivulidae Hypsolebias hellneri (Berkenkamp, 1993) Fr endemic    6.00 cm TL male/unsexed  Known from the São Francisco River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Hypsolebias igneus (Costa, 2000) Fr native   5.14 cm SL male/unsexed ;5.56 cm SL female  Known from the floodplains of the middle portion, left bank, of the rio São Francisco, between Barra and Igarité, Estado da Bahia, NE Brazil (Ref. 49550). + 
Rivulidae Hypsolebias janaubensis (Costa, 2006) Fr native   3.94 cm SL male/unsexed  Known from rio Gorutuba floodplains, upper rio Verde Grande drainage (Ref. 57610). - 
Rivulidae Hypsolebias longignatus (Costa, 2008) Fr native   2.87 cm SL male/unsexed ;3.04 cm SL female  Type locality, seasonal swamp in the Pacoti River floodplains, road CE-040, about 25 km of Fortaleza, Município de Aquiraz, Estado do Ceará, UFRJ 6614 (holotype of Simpsonichthys longignatus, 2.52 cm SL, male) (Ref. 78710). - 
Rivulidae Hypsolebias lopesi (Nielsen, Shibatta, Suzart & Martín, 2010) Fr native   4.58 cm SL male/unsexed ;3.45 cm SL female   - 
Rivulidae Hypsolebias lulai Ramos, Nielsen, Abrantes, Lira & Lustosa-Costa, 2023 Fr native   4.84 cm SL male/unsexed  Type locality of the holotype of Hypsolebias lulai: Trairi River basin, Recanto II settlement, Capim Grosso Lagoon, Lagoa Salgada (Ref. 130546). - 
Rivulidae Hypsolebias macaubensis (Costa & Suzart, 2006) Fr native   3.87 cm SL male/unsexed ;3.37 cm SL female  Known from the upper rio Paramirim drainage (Ref. 57610). - 
Rivulidae Hypsolebias magnificus (Costa & Brasil, 1991) Fr endemic    5.00 cm TL male/unsexed  Known from the middle São Francisco River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Hypsolebias marginatus (Costa & Brasil, 1996) Fr endemic    6.00 cm TL male/unsexed  Known from the São Francisco River basin (Ref. 36579). Type locality, Temporary pool near Rio dos Patos, trib. of Rio Maranhao, Rio Tocantins basin, Barro Alto, Goiás State, Brazil (Ref. 26282). + 
Rivulidae Hypsolebias martinsi Britzke, Nielsen & Oliveira, 2016 Fr native   3.42 cm SL male/unsexed ;2.93 cm SL female  Type locality of Hypsolebias martinsi: temporary pool near Rio Icaraizinho, Amontada, Ceara (Ref. 108434). - 
Rivulidae Hypsolebias mediopapillatus (Costa, 2006) Fr native    Known from rio São Domingos drainage, a part of the upper rio Verde Grande drainage (Ref. 57610). - 
Rivulidae Hypsolebias nitens Costa, 2012 Fr native   4.09 cm SL male/unsexed  Known only from seasonal lagoons in the floodplains of the lower Verde River, a right tributary of the middle São Francisco River, about 30 km N of the town of Itaguaçu,, Município de Itaguaçu da Bahia, Estado da Bahia (Ref. 89836). - 
Rivulidae Hypsolebias notatus (Costa, Lacerda & Brasil, 1990) Fr endemic    5.00 cm TL male/unsexed  Known from the upper Tocantins River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Hypsolebias nudiorbitatus Costa, 2011 Fr native    Known from the upper Itapicuru River basin in the semi-arid Caatinga area of northeastern Brazil (Ref. 88806). - 
Rivulidae Hypsolebias picturatus (Costa, 2000) Fr native   4.25 cm SL male/unsexed ;3.75 cm SL female  Occurs in the rio São Francisco basin, NE Brazil. Type locality, Estado da Bahia (Ref. 44211). Also Ref. 36579. + 
Rivulidae Hypsolebias pterophyllus Costa, 2012 Fr native   6.49 cm SL male/unsexed ;5.64 cm SL female  Known from several localities between the vicinity of the town of Igarité and the town of Paratinga, both situated on the banks of the São Francisco River (Ref. 89836). - 
Rivulidae Hypsolebias radiosus (Costa & Brasil, 2004) Fr native    Known from the upper Rio Tocantins basin, central Brazil (Ref. 53226). - 
Rivulidae Hypsolebias radiseriatus Costa, 2012 Fr native   4.71 cm SL male/unsexed ;4.42 cm SL female  Known only from the floodplains of Verde Grande River near the village of Gado Bravo, São Francisco River basin in Município de Monte Azul, Estado de Minas Gerais (Ref. 89836). - 
Rivulidae Hypsolebias sertanejo Costa, 2012 Fr, Thr native   4.75 cm SL male/unsexed ;3.94 cm SL female  Found in the vast area of the floodplains in the upper part of the middle section of the São Francisco River, about 10 km wide on each side of the main river channel, along a straight line parallel to the river channel of about 140 km between the areas near the villages of Manga and São Francisco, Minas Gerais state. The combination of the extent and occurrence is estimated to be below 5000 square kilometer. The continuing decline of the area of occupancy and number of populations may suggest that this species is endangered. (Ref. 89836). - 
Rivulidae Hypsolebias shibattai Nielsen, Martins, de Araujo & dos Reis Suzart, 2014 Fr, Thr native   3.44 cm SL male/unsexed ;2.57 cm SL female  Found only in a temporary pool beside the highway BR-430, at Bom Jesus da Lapa, rio São Francisco basin in Bahia state. Can be considered as critically endangered due to the ongoing pace of disturbance in its only known habitat from a single pool (Ref. 94796). - 
Rivulidae Hypsolebias splendissimus Costa, 2018 Fr native   4.33 cm SL male/unsexed ;3.05 cm SL female  Type lcoality of Hypsolebias splendissimus, middle São Francisco River basin, Guanambi, Bahia (Ref. 119423). - 
Rivulidae Hypsolebias tocantinensis Nielsen, Cruz & Baptista, 2012 Fr native    Known from the Rio Tocantins basin in Maranhão state (Ref. 92140). - 
Rivulidae Hypsolebias trifasciatus Nielsen, Martins, de Araujo, de Lira & Four, 2014 Fr native   3.30 cm SL male/unsexed ;2.40 cm SL female  Found only in a temporary pool beside the highway BA- 225, at Santa Rita de Cássia, rio Preto, rio São Francisco basin, Bahia state (Ref. 111470). - 
Characidae Hysteronotus megalostomus Eigenmann, 1911 Fr, Thr native  Piaba (Portuguese)  4.15 cm SL male/unsexed  Known from the upper São Francisco River basin (Ref. 38597). Type locality, Rio das Velhas, Mato Grosso (Ref. 30296). Regarded as threatened in the state of Minas Gerais (Ref. 26603). - 
Ictaluridae Ictalurus punctatus (Rafinesque, 1818) Fr introduced  Bagre americano (Portuguese)   132 cm TL male/unsexed    + 
Iguanodectidae Iguanodectes adujai Géry, 1970 Fr native   6.20 cm SL male/unsexed  Known from the Negro River basin (Ref. 38383). - 
Iguanodectidae Iguanodectes geisleri Géry, 1970 Fr native    5.52 cm SL male/unsexed  Known from Madeira and Negro River basins (Ref. 38383). + 
Iguanodectidae Iguanodectes gracilis Géry, 1993 Fr native   4.64 cm SL male/unsexed  Known from the Negro River basin (Ref. 38383). Museum: Rio Mamolé, affluent of Rio Cuiuini, Rio Negro system, MZUSP 45682 (holotype of I. Gracilis, 3.9 cm SL) (Ref. 27925). - 
Iguanodectidae Iguanodectes polylepis Géry, 1993 Fr native   8.45 cm SL male/unsexed  Known from Madeira and Purus River basins (Ref. 38383). Museum: tributary of Rio Ituxiou, Rio Purus basin, MZUSP 45684 (holotype of I. polylepis, 8.45 cm SL) (Ref. 27925). . - 
Iguanodectidae Iguanodectes purusii (Steindachner, 1908) Fr native    7.50 cm SL male/unsexed    - 
Iguanodectidae Iguanodectes rachovii Regan, 1912 Fr native    6.21 cm SL male/unsexed  Known from the Amazon River from Manaus to Belém, and coastal rivers close to Belém (north and south of the mouth of the Amazon River, including the Capim River) (Ref. 38383). - 
Iguanodectidae Iguanodectes spilurus (Günther, 1864) Fr native    10.15 cm SL male/unsexed  Also Ref. 598. + 
Iguanodectidae Iguanodectes variatus Géry, 1993 Fr native    10.30 cm SL male/unsexed  Known from Branco, Guaporé, Trombetas, and Urubu River basins (Ref. 38383). Museum: Igarapé Jatuarana, 5 km above Samuel, Rio Guaporé, Rondonia, MZUSP 45683 (holotype o fI. variatus, 10 cm SL) (Ref. 27925). - 
Pimelodidae Iheringichthys labrosus (Lütken, 1874) Fr, Fi native  Mandi-beiçudo (Portuguese), Mandi (Portuguese), Mandi bicudo (Portuguese), Papa isca (Portuguese)   43.50 cm TL female 12.8 TL Found in Piracicaba river (Ref. 50076) and the Uruguay River (Ref. 79585). + 
Pimelodidae Iheringichthys syi Azpelicueta & Britski, 2012 Fr native   22.00 cm TL male/unsexed  Known from the upper rio Paraná (Ref. 89852). - 
Pristigasteridae Ilisha amazonica (Miranda Ribeiro, 1920) Fr, Fi native  Apapa (Portuguese), Apapá (Portuguese), Asuna nahui (Portuguese), Sardinhão (Portuguese)   19.70 cm SL male/unsexed  Known from the Amazon River basin (Ref. 50628). Also Ref. 12202. + 
Heptapteridae Imparfinis cochabambae (Fowler, 1940) Fr native    6.00 cm SL male/unsexed   - 
Heptapteridae Imparfinis guttatus (Pearson, 1924) Fr native    12.70 cm SL male/unsexed   - 
Heptapteridae Imparfinis hasemani Steindachner, 1915 Fr endemic   8.10 cm SL male/unsexed  Known from Branco and Tapajós River basins (Ref. 36914). Type locality, Rio Surumú near Serra do Mello; Rio Branco at Bem Querer; Rio Tapajos near Santarém, Pará (Ref. 36656). - 
Heptapteridae Imparfinis hollandi Haseman, 1911 Fr native   23.00 cm SL male/unsexed  Found in the Rio Iguaçu in Porto União da Victoria, Sta. Catarina (Ref. 6868). Also Ref. 36914. - 
Heptapteridae Imparfinis minutus (Lütken, 1874) Fr native  Bagre (Portuguese), Bagrinho (Portuguese), Mandi (Portuguese), Mandizinho (Portuguese)   12.00 cm SL male/unsexed  Occurs in the upper São Francisco River basin (Ref. 36914). Type locality, Rio das Velhas (Ref. 36914). + 
Heptapteridae Imparfinis mirini Haseman, 1911 Fr endemic  Bagrinho (Portuguese), Lobó (Portuguese), Mandizinho (Portuguese)   8.50 cm SL male/unsexed  Known from the upper Araguaia and Paraná River basins (Ref. 36914). Recorded from the Jacutinga and Quinta streams, in Piracicaba, São Paulo (Ref. 6868), and Pardo River, upper Paraná River basin, southeastern Brazil (Ref. 27745). Recorded from Córrego Barreiro (Ref. 53011). + 
Heptapteridae Imparfinis piperatus Eigenmann & Norris, 1900 Fr endemic  Mandi pintado (Portuguese)  3.20 cm SL male/unsexed  Occurs in Betari River basin, Southeastern Brazil (Ref. 38979). Type locality: Sao Paulo, Brazil (Ref. 6868). Also Ref. 36914. + 
Heptapteridae Imparfinis pristos Mees & Cala, 1989 Fr native   3.80 cm SL male/unsexed  Occurs in the Negro River basin (Ref. 36914). + 
Heptapteridae Imparfinis schubarti (Gomes, 1956) Fr endemic  Bagrinho (Portuguese), Lobó (Portuguese), Mandizinho (Portuguese)  9.30 cm SL male/unsexed  Occurs in the upper Paraná River basin (Ref. 36914). + 
Heptapteridae Imparfinis stictonotus (Fowler, 1940) Fr native  Bagrinho (Portuguese), Mandizinho (Portuguese)   4.80 cm SL male/unsexed  Occurs in the Mamoré/Madeira River, Paraguay (Ref. 36914), Machado (Ref. 97589) and Acre River basins (Ref. 97592). - 
Characidae Inpaichthys kerri Géry & Junk, 1977 Fr native  Puxa-puxa (Portuguese)  2.80 cm SL male/unsexed  Known from the Aripuanã River, upper Madeira River basin, Mato Grosso (Ref. 38376). + 
Rhamphichthyidae Iracema caiana Triques, 1996 Fr native   36.00 cm TL male/unsexed  Known from Jauaperi River basin in Negro River drainage (Ref. 36685). - 
Loricariidae Isbrueckerichthys alipionis (Gosline, 1947) Fr native   8.15 cm SL male/unsexed  Known from the rio Betari, in the rio Ribeira do Iguape basin, in São Paulo State. Type locality, almost certainly the Ribeirão do Monjolinho in the Iporanga basin of Sao Paulol (Ref. 42856). Also Ref. 6868, 36817. - 
Loricariidae Isbrueckerichthys calvus Jerep, Shibatta, Pereira & Oyakawa, 2006 Fr native   9.02 cm SL male/unsexed  Found only in the córrego Juruba and ribeirão Agua dos Oito, affluents of rio Taquara of the rio Tibagi basin in Paraná State (Ref. 57731). - 
Loricariidae Isbrueckerichthys duseni (Miranda Ribeiro, 1907) Fr native  Cascudinho (Portuguese)  9.88 cm SL male/unsexed  Known only from the upper reaches of the rio Ribeira do Iguape, in Paraná State. Type locality: ribeirão do Monjolinho, 300 m above sea level, a tributary of the rio Betari, near Iporanga, Sao Paulo (Ref. 42856). Also Ref. 6868, 36817. - 
Loricariidae Isbrueckerichthys epakmos Pereira & Oyakawa, 2003 Fr endemic   10.30 cm SL male/unsexed  Type locality: rio Verde at Piúva, a tributary of the R. Ribeira de Iguape basin, São Paulo State. Other localities: rio Juquiá, same basin, at Cachoeira de Fumaça; rio Coruja, tributary to rio Juquiá, near Cachoeira do Chá (Ref. 52250). - 
Loricariidae Isbrueckerichthys saxicola Jerep, Shibatta, Pereira & Oyakawa, 2006 Fr native   8.77 cm SL male/unsexed  Found only in the headwater of ribeirão Jacutinga of the rio Tibagi basin in Paraná State (Ref. 57731). - 
Trichomycteridae Ituglanis agreste Lima, Neves & Campos-Paiva, 2013 Fr native   4.41 cm SL male/unsexed  Known only from rio Tarugo, a tributary of the rio Uruba, that flows into rio Gongogi, principal drainage of right margin on the middle section of rio de Contas basin in Bahia State (Ref. 94155). - 
Trichomycteridae Ituglanis amazonicus (Steindachner, 1882) Fr native  Candiru (Portuguese), Cambeva (Portuguese)   7.50 cm NG male/unsexed  Known from the Amazon (Ref. 39970) and Machado River basins (Ref. 97589). Type locality: Codajaz, Brazil (Ref. 6868). + 
Trichomycteridae Ituglanis amphipotamus Mendonça, Oyakawa & Wosiacki, 2018 Fr native     - 
Trichomycteridae Ituglanis apteryx Datovo, 2014 Fr native   6.72 cm SL male/unsexed  Known from the reservoir formed during the building of the Buriti Hydroelectric Dam, across the Rio Curuá, Rio Xingu basin, Rio Amazonas drainage in Pará State (Ref. 95610). - 
Trichomycteridae Ituglanis australis Datovo & de Pinna, 2014 Fr native   7.56 cm SL male/unsexed  Known from the Laguna dos Patos basin (Ref. 95054). - 
Trichomycteridae Ituglanis bambui Bichuette & Trajano, 2004 Fr native   4.63 cm SL male/unsexed  Found in two upper tributaries of the main stream in the Angelica Cave which are 7,000 m far apart, indicating a wide distribution in the epikarst (Ref. 55401). - 
Trichomycteridae Ituglanis boitata Ferrer, Donin & Malabarba, 2015 Fr native   12.26 cm SL male/unsexed  Known from rio Araranguá, rio Mampituba and rio Tramandaí basins in southern Brazil (Ref. 104908). - 
Trichomycteridae Ituglanis cahyensis Sarmento-Soares, Martins-Pinheiro, Aranda & Chamon, 2006 Fr native    4.86 cm SL male/unsexed  Found only in rio Palmares, a tributary of the rio Cahy, a small coastal river drainage from southeastern Bahia State (Ref. 57703). + 
Trichomycteridae Ituglanis compactus Castro & Wosiacki, 2017 Fr native   2.58 cm SL male/unsexed  Known from rio Iratapuru, a left-bank tributary of the rio Jari, Amapá State. The hydroelectric dam of Santo Antônio do Jari, situated between the municipalities of Almeirim in Pará and Laranjal do Jari in Amapá, is the main threat of this species as it abruptly alters the natural characteristics of the regional aquatic ecosystem and can affect the survival of this and other species (Ref. 116503). - 
Trichomycteridae Ituglanis eichorniarum (Miranda Ribeiro, 1912) Fr native   5.69 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 39970). Type locality: Cácares, Rio Paraguay, Mato Grosso, Brazil (Ref. 26282). - 
Trichomycteridae Ituglanis epikarsticus Bichuette & Trajano, 2004 Fr native  scarce (very unlikely) 3.40 cm SL male/unsexed  Known from a single set of rimstone dams in São Mateus Cave, central Brazil (Ref. 55401). - 
Trichomycteridae Ituglanis goya Datovo, Aquino & Langeani, 2016 Fr native   9.17 cm SL male/unsexed  Type locality of Ituglanis goya, Goiás, Planaltina, district of São Gabriel de Goiás; Rio Tocantins basin, Ribeirão Cocal, under bridge of GO-118 Road. Known from the tributaries of the right margin of the Rio Paranaíba, Upper Paraná, La Plata Province, and from several watercourses of the upper portion of the Rio Tocantins basin, Amazon Province (Ref. 117615). - 
Trichomycteridae Ituglanis herberti (Miranda Ribeiro, 1940) Fr native   16.00 cm SL male/unsexed  Known from the Bodoquena River in Paraguay River basin (Ref. 39970). Type locality: Rio Bodoquena, Mato Grosso, Brazil (Ref. 6868). - 
Trichomycteridae Ituglanis ina Wosiacki, Dutra & Mendonça, 2012 Fr native   6.20 cm SL male/unsexed  Type locality. Known from the tributaries of rio Parauapebas, a tributary of the rio Itacaiúnas, which is in turn a tributary of the right bank of the rio Tocantins, Serra dos Carajás, State of Pará (Ref. 91742). - 
Trichomycteridae Ituglanis macunaima Datovo & Landim, 2005 Fr native   4.63 cm SL male/unsexed  Known from the rio Araguaia basin in Mato Grosso (Ref. 56915). - 
Trichomycteridae Ituglanis mambai Bichuette & Trajano, 2008 Fr native   6.83 cm SL male/unsexed  Found in a single subterranean stream inside the Lapa do Sumidouro Cave (upper rio Tocantins basin) in Posse, northeastern State of Goiás (Ref. 75008). - 
Trichomycteridae Ituglanis paraguassuensis Campos-Paiva & Costa, 2007 Fr native   4.30 cm SL male/unsexed   - 
Trichomycteridae Ituglanis parahybae (Eigenmann, 1918) Fr native    5.10 cm NG male/unsexed  Known from Paraíba do Sul and São João River basins (Ref. 39970). - 
Trichomycteridae Ituglanis parkoi (Miranda Ribeiro, 1944) Fr native   17.00 cm NG male/unsexed  Known from the Amazon River basin (Ref. 39970). Type locality: Rio Javarí [R. Iticoaí], Amazonas, Brazil (Ref. 26282, 6868). - 
Trichomycteridae Ituglanis passensis Fernández & Bichuette, 2002 Fr native   7.00 cm SL male/unsexed  Type locality, subterranean stream in the Tocantins drainage, Passa Três cave, São Domingos, Goiás (Ref. 46923). Also Ref. 39970. + 
Trichomycteridae Ituglanis proops (Miranda Ribeiro, 1908) Fr native   8.70 cm NG male/unsexed  Known from the Ribeira de Iguape River basin (Ref. 39970). Recorded from Rio Paraiba basin; Sao Paulo (Ref. 6868). - 
Trichomycteridae Ituglanis ramiroi Bichuette & Trajano, 2004 Fr native   3.13 cm SL male/unsexed  Found only in a pool formed by infiltration of water in the São Bernardo Cave in central Brazil (Ref. 55401). - 
Anablepidae Jenynsia diphyes Lucinda, Ghedotti & da Graça, 2006 Fr native   5.51 cm SL male/unsexed ;7.30 cm SL female  Presently found only in Córrego Passo do Aterrado and Rio das Torres, both tributaries of the left margin of the Rio Jordão in the Rio Iguaçu drainage (Ref. 75966). - 
Anablepidae Jenynsia eigenmanni (Haseman, 1911) Fr native     Type locality, creek near Serrinha Paraná, Rio Iguassu (Ref. 26282). - 
Anablepidae Jenynsia eirmostigma Ghedotti & Weitzman, 1995 Fr native    7.10 cm SL male/unsexed  Found in the upper Uruguay and Jacui River basins (Ref. 80013). Type locality, Rio Grande do Sul, Rio Manoel Leao, Município de Cambará do Sul, near Sao José dos Ausentes, Brazil (Ref. 30913). Also Ref. 33161. - 
Anablepidae Jenynsia lineata (Jenyns, 1842) Fr native  Barrigudinho (Portuguese)  7.66 cm SL male/unsexed 3.75 SL Known from the Lago de Freitas in Rio de Janeiro (Ref. 26130) and recorded from the southern Río Grande do Sul Province (Ref, 30912). Also Ref. 4537. + 
Anablepidae Jenynsia onca Lucinda, Reis & Quevedo, 2002 Fr native    5.50 cm SL male/unsexed  Known from the Rio Ibicui drainage, a tributary of lower Rio Uruguai (Ref. 42933). Type locality, rio Inhacundá about 500 m upstream pottery, Rio Grande do Sul (Ref. 42933). + 
Anablepidae Jenynsia sanctaecatarinae Ghedotti & Weitzman, 1996 Fr native    3.70 cm SL male/unsexed ;4.18 cm SL female  Type locality, Rio Pique off road between Meleiro and Aranagua, Morro Cortado, Santa Catarina (Ref. 30912). - 
Anablepidae Jenynsia unitaenia Ghedotti & Weitzman, 1995 Fr native    7.60 cm SL male/unsexed  Found in coastal rivers in Santa Catarina and northeastern Rio Grande do Sul States (Ref. 80013). Type locality, Rio Faxinalzinho at Mae dos Homens near Praia Grande, Município de Praia Grande, Santa Catarina (Ref. 30913). + 
Anablepidae Jenynsia weitzmani Ghedotti, Meisner & Lucinda, 2001 Fr native    7.60 cm SL male/unsexed ;7.02 cm SL female  Type locality: Trib. of rio Pinheiros near Anitápolis, 7 km from road SC-407, ca. 27°54'S, 49°07'W, Santa Catarina State, Brazil (Ref. 45800). - 
Characidae Jupiaba acanthogaster (Eigenmann, 1911) Fr native  Lambari (Portuguese)   5.50 cm SL male/unsexed  Recorded from Paraguay, upper Tapajos and Tocantins River basins (Ref. 38376). + 
Characidae Jupiaba ajuricaba (Marinho & Lima, 2009) Fr native   9.52 cm SL male/unsexed  Found in the upper rio Negro basin at the rio Tiquié, a large tributary from the rio Uaupés, the middle and lower rio Negro areas at Santa Isabel do Rio Negro and Anavilhanas archipelago, respectively, and the lower rio Tapajós basin. Also recorded from the lago Castanho, a large lake connected to the better-known lago Janauacá, both of which are situated at the floodplains of the rio Solimões, in the central Amazon basin (Ref. 81201). - 
Characidae Jupiaba anterior (Eigenmann, 1908) Fr native   11.13 cm SL male/unsexed  Found in the Amazon River basin (Ref. 38376). - 
Characidae Jupiaba anteroides (Géry, 1965) Fr native    7.45 cm SL male/unsexed  Found in the upper Amazon and Curuá-Una River basins (Ref. 38376). - 
Characidae Jupiaba apenima Zanata, 1997 Fr native   5.86 cm TL male/unsexed  Known from Peixoto de Azevedo and Noedori River basins (Ref. 38376). Recorded from Almas, Rio do Peixe, rio Tocantins basin in Tocantins (Ref. 96859). - 
Characidae Jupiaba asymmetrica (Eigenmann, 1908) Fr native    Found in the upper Amazon River basin (Ref. 38376). - 
Characidae Jupiaba atypindi Zanata, 1997 Fr native    Found in Negro River and some of its tributaries including the Uraricoera, Surumu, and Cuminá rivers (Ref. 38376). - 
Characidae Jupiaba citrina Zanata & Ohara, 2009 Fr native   6.05 cm SL male/unsexed  Reported from Machado river basin (Ref. 97589). + 
Characidae Jupiaba elassonaktis Pereira & Lucinda, 2007 Fr native    Known from the rio Tocantins drainage (Ref. 72401). - 
Characidae Jupiaba iasy Netto-Ferreira, Zanata, Birindelli & Sousa, 2009 Fr native   4.71 cm SL male/unsexed   - 
Characidae Jupiaba kurua Birindelli, Zanata, Sousa & Netto-Ferreira, 2009 Fr native   8.66 cm SL male/unsexed  Found in the upper rio Curuá (above the two great falls in Serra do Cachimbo), a tributary of rio Iriri, a large tributary of the lower rio Xingu. Its absence below the waterfalls suggests that this species might be restricted to the isolated river portion above the falls (Ref. 80699). - 
Characidae Jupiaba minor (Travassos, 1964) Fr native    Found in the and Cachimbo River basin in Pará (Ref. 38376). Recorded from Rio Tapajoz basin (Ref. 598). - 
Characidae Jupiaba ocellata (Géry, Planquette & Le Bail, 1996) Fr native   12.00 cm TL male/unsexed  Occurs in Rio Paru de Oeste in the state of Para and in Curua Una (Ref. 12225). - 
Characidae Jupiaba paranatinga Netto-Ferreira, Zanata, Birindelli & Sousa, 2009 Fr native   3.76 cm SL male/unsexed   - 
Characidae Jupiaba pirana Zanata, 1997 Fr native   4.35 cm SL male/unsexed   - 
Characidae Jupiaba poekotero Zanata & Lima, 2005 Fr native  Utaseã (Portuguese), Poekotero-potatigu (Portuguese), Utasako (Portuguese)  6.80 cm SL male/unsexed  Known only from the upper Rio Tiquié, a tributary of the lower course of the Rio Uaupés (Vaupés in Colombia), upper Rio Negro basin in Amazonas (Ref. 54762). Collected only at Caruru and nearby sites dowstreams (Ref. 54762). - 
Characidae Jupiaba polylepis (Günther, 1864) Fr native   7.30 cm TL male/unsexed  Known from Xingu, Tocantins and Araguaia rivers. - 
Characidae Jupiaba poranga Zanata, 1997 Fr native   8.02 cm SL male/unsexed  Reported from Machado river basin (Ref. 97589). - 
Characidae Jupiaba scologaster (Weitzman & Vari, 1986) Fr native   3.70 cm SL male/unsexed  Museum: Amazonas, Rio Negro, MZUSP 30247 (Ref. 27925). - 
Characidae Jupiaba yarina Zanata, 1997 Fr native   7.73 cm SL male/unsexed   - 
Characidae Jupiaba zonata (Eigenmann, 1908) Fr native    4.71 cm SL male/unsexed  Reported from Machado river basin (Ref. 97589). - 
Engraulidae Jurengraulis juruensis (Boulenger, 1898) Fr native    17.90 cm SL male/unsexed    + 
Doradidae Kalyptodoras bahiensis Higuchi, Britski & Garavello, 1990 Fr native  Peracuca (Portuguese)   24.50 cm SL male/unsexed  Found in Rio Paraguaçu (Ref. 26714). + 
Crenuchidae Klausewitzia ritae Géry, 1965 Fr native   2.50 cm SL male/unsexed  Recorded from the Igarapé Préto, along Upper Amazon, near Belem, about 60 km below Leticia, Amazonas (Ref. 13683). Also Ref. 37059. - 
Characidae Knodus breviceps (Eigenmann, 1908) Fr native  Piaba (Portuguese)   8.70 cm TL male/unsexed  Found in the Tocantins River basin (Ref. 38376). + 
Characidae Knodus chapadae (Fowler, 1906) Fr native   5.70 cm SL male/unsexed  Recorded from Mato Grosso (Ref. 598). Known from the upper Paraguay River basin (Ref. 38376). - 
Characidae Knodus delta Géry, 1972 Fr native    3.61 cm SL male/unsexed  Found in the Purus and Acre River basins (Ref. 97592). - 
Characidae Knodus dorsomaculatus Ferreira & Netto-Ferreira, 2010 Fr native   4.81 cm SL male/unsexed  Type locality, Pará, Jacareacanga, tributary of the Teles Pires River, Tapajós Basin, MZUSP 102823 (holotype of Knodus dorsomaculatus, 4.8 cm SL). Known only from the Teles Pires River, a tributary of the Tapajós River (Ref. 85071). - 
Characidae Knodus figueiredoi Esguícero & Castro, 2014 Fr native   3.17 cm SL male/unsexed  Known from the Rio das Gasças, upper Rio Araguaia basin (Ref. 97362). - 
Characidae Knodus geryi Lima, Britski & Machado, 2004 Fr native   6.48 cm SL male/unsexed  Known only from the rio do Peixe, a tributary of the rio Cabaçal, in the upper rio Paraguay basin, Mato Grosso (Ref. 55831). - 
Characidae Knodus heteresthes (Eigenmann, 1908) Fr native   5.10 cm TL male/unsexed  Occurs in Rio Tapajoz (Ref. 12225). Found in Machado river basin (Ref. 97589). + 
Characidae Knodus moenkhausii (Eigenmann & Kennedy, 1903) Fr native    4.50 cm TL male/unsexed   + 
Characidae Knodus savannensis Géry, 1961 Fr native   5.96 cm TL male/unsexed  Known from the Tocantins River basin (Ref. 38376). - 
Characidae Knodus smithi (Fowler, 1913) Fr native    3.50 cm TL male/unsexed  Found in the Madeira River basin (Ref. 38376). - 
Characidae Knodus tiquiensis Ferreira & Lima, 2006 Fr native   7.26 cm SL male/unsexed  Found only in upper Rio Tiquié basin, a tributary of the Rio Uaupés in the upper Rio Negro basin, Amazonas. Widely distributed in the upper Rio Tiquié, occurring above large waterfalls such as the Cachoeira do Caruru, Cachoeira da Pedra Curta, and Cachoeira Comprida. Reported by Tukano and Tuyuka fishermen to occur all along the upper Rio Tiquié (Ref. 75965). - 
Characidae Knodus victoriae (Steindachner, 1907) Fr native     Recorded from the Parnahyba river. + 
Characidae Kolpotocheirodon figueiredoi Malabarba, Lima & Weitzman, 2004 Fr native   3.05 cm SL male/unsexed ;3.10 cm SL female  Found only in rio Pratinha in Bahia, a tributary of the rio Santo Antônio, itself a tributary of the rio Paraguaçu, a coastal drainage of eastern Brazil (Ref. 76978). - 
Characidae Kolpotocheirodon theloura Malabarba & Weitzman, 2000 Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese), Piaba (Portuguese)  2.99 cm SL male/unsexed  Known from the uppermost tributaries of the São Francisco and Paraná rivers near Brasília (Ref. 37055). - 
Cichlidae Krobia guianensis (Regan, 1905) Fr native    12.80 cm SL male/unsexed  Known from Araguari river basin, Amapá (Ref. 101387). + 
Cichlidae Krobia xinguensis Kullander, 2012 Fr native   8.60 cm SL male/unsexed  Found only in the Xingu river drainage, with several localities in headwaters in Mato Grosso and the type locality at the Ilha Babaquara, close to Altamira (Ref. 89398) + 
Loricariidae Kronichthys heylandi (Boulenger, 1900) Fr native  Cascudinho (Portuguese), Heyland's suckermouth catfish (English)  15.00 cm TL male/unsexed ;8.80 cm SL female  Type locality: Mountain stream near Santos, Sao Paulo State, Brazil, elev. 400 ft. (Ref. 26282, 6868). Also in Betari River basin, Southeastern Brazil (Ref. 38979). + 
Loricariidae Kronichthys lacerta (Nichols, 1919) Fr native   7.00 cm SL male/unsexed  Type locality: Poço Grande, Rio Juquia, Estado de Sao Paulo, Brazil (Ref. 26282, 6868). - 
Loricariidae Kronichthys subteres Miranda Ribeiro, 1908 Fr native  Mãe-do-anhá (Portuguese), Anhã (Portuguese)   12.00 cm TL male/unsexed  Type locality: Rio Betari [Betharí], Rio Pardo, Rio Iporanga, Brazil (Ref. 26282, 6868). + 
Rivulidae Kryptolebias brasiliensis (Valenciennes, 1821) Fr endemic  Rívulo (Portuguese)  6.00 cm TL male/unsexed   + 
Rivulidae Kryptolebias campelloi (Costa, 1990) Fr endemic   6.00 cm TL male/unsexed   - 
Rivulidae Kryptolebias caudomarginatus (Seegers, 1984) Fr endemic    6.00 cm TL male/unsexed    - 
Rivulidae Kryptolebias gracilis Costa, 2007 Fr native   2.76 cm SL male/unsexed  Known from the Mato Grosso River drainage, Saquarema Lagoon basin in Municipio de Saquarema, Estado do Rio de Janeiro, southeastern Brazil (Ref. 72398). - 
Rivulidae Kryptolebias hermaphroditus Costa, 2011 Fr native    Known only from the coastal plains of Rio de Janeiro and São Paulo in southeastern Brazil (Ref. 87200). + 
Rivulidae Kryptolebias marmoratus (Poey, 1880) Fr native   7.50 cm TL male/unsexed   + 
Rivulidae Kryptolebias ocellatus (Hensel, 1868) Fr native    6.00 cm TL male/unsexed    + 
Anostomidae Laemolyta fernandezi Myers, 1950 Fr native  Aracu (Portuguese), Casca seca (Portuguese), Piau (Portuguese), Piau boca fina (Portuguese), Piau crote (Portuguese), Piau curimatá (Portuguese), Piau de loca (Portuguese)   25.00 cm SL male/unsexed  Known from the Amazon basin in rios Xingu, Tocantins and Araguaia (Ref. 80799). + 
Anostomidae Laemolyta garmani (Borodin, 1931) Fr native   21.40 cm SL male/unsexed  Known from the Amazon River (Ref. 36801). + 
Anostomidae Laemolyta nitens (Garman, 1890) Fr native     + 
Anostomidae Laemolyta proxima (Garman, 1890) Fr native  Aracú-caneta (Portuguese)   28.50 cm SL male/unsexed  Known from Guaporé River basin (Ref. 36801). Type locality: Villa Bella and Ueranduba, Brazil (Ref. 26282). - 
Anostomidae Laemolyta taeniata (Kner, 1858) Fr native  Piau-vara (Portuguese), Aracú-caneta (Portuguese), Uaracu biribiri (Portuguese) fairly common (chances are about 50%) 28.80 cm SL male/unsexed  Found in the middle Amazon; common in the Rio Negro (Ref. 598). Also Ref. 36801. + 
Anostomidae Laemolyta varia (Garman, 1890) Fr native    Type locality: Gurupa; Jose Fernandez; Lake Hyanuary; Manaos; Obydos; Porto do Moz; and Rio Negro, Brazil. + 
Cichlidae Laetacara araguaiae Ottoni & Costa, 2009 Fr native   3.63 cm SL male/unsexed  Known from the Rio Verde, rio Araguaia basin in central Brazil (Ref. 80972). + 
Cichlidae Laetacara curviceps (Ahl, 1923) Fr endemic  Curvicepe (Portuguese)  4.60 cm SL male/unsexed ;6.60 cm female  Found in the lower portions of tributaries of the Amazon River (Ref. 36377). + 
Cichlidae Laetacara dorsigera (Heckel, 1840) Fr native  Cará (Portuguese), Acará (Portuguese), Acará bobo (Portuguese), Acará pataquira (Portuguese), Cará bobo (Portuguese), Carazinho (Portuguese)   6.00 cm SL male/unsexed  Known from the Paraná River basin in the Paraguay River drainage (Ref. 36377). + 
Cichlidae Laetacara flamannellus Ottoni, Bragança, Amorim & Gama, 2012 Fr native   3.82 cm SL male/unsexed  Found along eastern coastal rivers of Amapá state, which overflows during the rainy season, originating huge floodplains. The northernmost record is from Igarapé do Davi, in Amapá municipality and the southernmost record is from córrego Areal, in Mazagão municipality (Ref. 91058). - 
Cichlidae Laetacara flavilabris (Cope, 1870) Fr native   8.20 cm SL male/unsexed  Known from the Amzon River basin in the upper Solimöes and Juruá River basins (Ref. 36377). + 
Cichlidae Laetacara thayeri (Steindachner, 1875) Fr native    12.00 cm TL male/unsexed  Found along the Solimões, Amazon (to lower Trombetas River) and lower Negro River basins (Ref. 36377). + 
Rivulidae Laimosemion amanapira (Costa, 2004) Fr native    Known from the upper rio Negro drainage, Amazonian basin in northern Brazil (Ref. 52792). - 
Rivulidae Laimosemion dibaphus (Myers, 1927) Fr endemic   4.00 cm TL male/unsexed  Museum: Igarapé do Ajamuri, Lower Amazon, CAS 44214 (lectotype of R. dibaphus) (Ref. 36579). + 
Rivulidae Laimosemion geayi (Vaillant, 1899) Fr native   5.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Laimosemion kirovskyi (Costa, 2004) Fr native   2.27 cm SL male/unsexed ;1.72 cm SL female  Found only in the floodplains of igarapé Acará, lower rio Negro drainage of the rio Amazonas basin in northern Brazil (Ref. 54752). - 
Rivulidae Laimosemion romeri (Costa, 2003) Fr native    Type locality, Brook tributary to Igarapé Iauiari, ca. 0°14.31'N, 68°03.48'W, trib. of Uaupés R. which is a trib. of Negro R., Amazon basin, Amazonas, n. Brazil (Ref. 54621). + 
Rivulidae Laimosemion strigatus (Regan, 1912) Fr native   6.00 cm TL male/unsexed  Known from the lower Amazon River basin (Ref. 36579). - 
Rivulidae Laimosemion uakti (Costa, 2004) Fr native    Known from the upper rio Negro drainage, Amazonian basin in northern Brazil. - 
Rivulidae Laimosemion uatuman (Costa, 2004) Fr native    Known from Rio Uatumã drainage, cenral Amazonian basin (Ref. 52555). - 
Rivulidae Laimosemion ubim Costa & Lazzarotto, 2014 Fr native   1.81 cm SL male/unsexed ;1.70 cm SL female  Found only in one locality near Igarapé do Ubím, a stream draining into Lago Amanã, Japurá-Solimões drainage system, Rio Amazonoas basin in northern Brazil (Ref. 95522). - 
Rivulidae Laimosemion xiphidius (Huber, 1979) Fr native   4.50 cm TL male/unsexed ;3.00 cm TL female   + 
Loricariidae Lamontichthys avacanoeiro de Carvalho Paixão & Toledo-Piza, 2009 Fr native   15.99 cm SL male/unsexed  Type locality, Goiás, rio Tocantins, pools below U.H.E. Serra da Mesa, MNRJ 32795 (holotype of Lamontichthys avacanoeiro, 15.05 cm SL) (Ref. 83332). - 
Loricariidae Lamontichthys filamentosus (La Monte, 1935) Fr native  Bode cachimbo (Portuguese), Bode cachoeira (Portuguese)   16.70 cm SL male/unsexed  Known from the Amazon River (Ref. 36389). + 
Loricariidae Lamontichthys parakana de Carvalho Paixão & Toledo-Piza, 2009 Fr native   13.13 cm SL male/unsexed  Type locality, Pará, lower rio Tocantins basin, rio Tocantins, below dam of Tucuruí, INPA 3010 (holotype of Lamontichthys parakana, 11.27 cm SL) (Ref. 83332). - 
Loricariidae Lampiella gibbosa (Miranda Ribeiro, 1908) Fr native   5.00 cm TL male/unsexed  Type locality: Rio Bethary [Betharí], Sao Paulo, Brazil (Ref. 26282). - 
Loricariidae Lasiancistrus saetiger Armbruster, 2005 Fr native   10.01 cm SL male/unsexed  Type locality, Pará, rio Guamá near Ourém, MCP 37942 (holotype of Lasiancistrus saetiger, 10.01 cm SL), purchased from an aquarium dealer (Ref. 56920). - 
Loricariidae Lasiancistrus schomburgkii (Günther, 1864) Fr native    14.40 cm SL male/unsexed  Known from the Madeira and upper Guaporé River basins (Ref. 36713). Also recorded from Aripuanã (Ref. 46237) and Machado River (Ref. 97589). Also Ref. 6868, 56920. + 
Lebiasinidae Lebiasina intermedia Meinken, 1936 Fr native   10.70 cm TL male/unsexed   - 
Lebiasinidae Lebiasina marilynae Netto-Ferreira, 2012 Fr native   8.88 cm SL male/unsexed  Known from a single collection site in the rio Curuá, rio Xingu basin (Ref. 91748). - 
Lebiasinidae Lebiasina melanoguttata Netto-Ferreira, 2012 Fr native   6.84 cm SL male/unsexed  Known from two tributaries of the rio Curuá (rio Xingu basin) in Serra do Cachimbo (Ref. 91748). - 
Lebiasinidae Lebiasina minuta Netto-Ferreira, 2012 Fr native   6.84 cm SL male/unsexed  Known from two tributaries of the rio Curuá (rio Xingu basin) in Serra do Cachimbo (Ref. 91748). - 
Lebiasinidae Lebiasina yepezi Netto-Ferreira, Oyakawa, Zuanon & Nolasco, 2011 Fr native   15.29 cm SL male/unsexed  Known from Rio Parima (rio Mucajaí system) and rio Uraricoera in the rio Branco drainage, rio Amazonas system, Roraima State; and rio Marari (rio Padauari system) in the rio Negro drainage, rio Amazonas system, Amazonas State (Ref. 88953). - 
Pimelodidae Leiarius arekaima (Jardine, 1841) Fr native  Arekaima (Portuguese), Aruá (Portuguese), Jandiá (Portuguese), Jundiá (Portuguese), Yacima (Portuguese)   Known from the Rio Branco. - 
Pimelodidae Leiarius longibarbis (Castelnau, 1855) Fr native    Type locality, Amazon River (Ref. 56787). + 
Pimelodidae Leiarius marmoratus (Gill, 1870) Fr, Fi native  Jundiá (Portuguese), Jandiá (Portuguese), Mandi bandeira (Portuguese), Mandi de pedra (Portuguese), Peixe pedra (Portuguese)   100.00 cm TL male/unsexed  Quite abundant in São Benedito River (Ref. 54668). Usually found in riverbeds and deep wells, but also occurs in lakes especially the young (Ref. 54668). Young or sub-adults form large schools (Ref. 54668). Prefers to lay over rock and tree trunks during the day, being more active at sunrise, sunset and night (Ref. 54668). + 
Pimelodidae Leiarius pictus (Müller & Troschel, 1849) Fr native    60.00 cm TL male/unsexed    + 
Characidae Lepidocharax burnsi Ferreira, Menezes & Quagio-Grassiotto, 2011 Fr native   3.99 cm SL male/unsexed  Known from the tributaries of the upper rio São Francisco and rio Doce basins (Ref. 87315). - 
Characidae Lepidocharax diamantina Ferreira, Menezes & Quagio-Grassiotto, 2011 Fr native   3.88 cm SL male/unsexed  Found in rio Paraguaçu basin, an independent costal river system in Bahia State, northeastern Brazil (Ref. 87315). - 
Lepidosirenidae Lepidosiren paradoxa Fitzinger, 1837 Fr native  Piracourou-boia (Portuguese), Boi una (Portuguese), Caramuru (Portuguese), Carapaná (Portuguese), Cobra dágua (Portuguese), Loalach (Portuguese), Loloque (Portuguese), Piracuru-bóia (Portuguese), Piramboia (Portuguese), Pirambóia (Portuguese), Pirarucu bóia (Portuguese), Pirarucubóia (Portuguese), Tariíra bóia (Portuguese), Tarira bóia (Portuguese), Tarrira-boia (Portuguese), Tarrira-bóia (Portuguese), Traíra bóia (Portuguese), Trairam bóia (Portuguese)   125 cm TL male/unsexed  Known from Marajo I., Tapajoz River, Obidus region, Madeira River, and Negro River (Ref. 12225). Also Ref. 4537, 36887. + 
Centrarchidae Lepomis cyanellus Rafinesque, 1819 Fr introduced   31.00 cm TL male/unsexed   + 
Centrarchidae Lepomis gibbosus (Linnaeus, 1758) Fr introduced    40.00 cm TL male/unsexed   + 
Centrarchidae Lepomis macrochirus Rafinesque, 1819 Fr not established   41.00 cm TL male/unsexed   + 
Loricariidae Leporacanthicus galaxias Isbrücker & Nijssen, 1989 Fr native   21.10 cm SL male/unsexed  Known from the southern tributaries of the middle and lower Amazon, Madeira, Tocantins and Guamá rivers (Ref. 36713). + 
Loricariidae Leporacanthicus heterodon Isbrücker & Nijssen, 1989 Fr endemic   16.00 cm TL male/unsexed  Known from Xingu River basin (Ref. 36713). + 
Loricariidae Leporacanthicus joselimai Isbrücker & Nijssen, 1989 Fr native   9.80 cm SL male/unsexed  Known from Tapajós River basin (Ref. 36713). + 
Anostomidae Leporellus cartledgei Fowler, 1941 Fr native  Taguara (Portuguese)    Known from São Francisco basin (Ref. 57478). - 
Anostomidae Leporellus pictus (Kner, 1858) Fr native  Charuto (Portuguese), Piau (Portuguese), Solteira (Portuguese), Taguara (Portuguese), Timboré (Portuguese)   Known from Paraná and São Francisco River basins (Ref. 36801). + 
Anostomidae Leporellus retropinnis (Eigenmann, 1922) Fr native     Known from Paraná River basin (Ref. 36801). Recorded from Rio Piracicabia (Ref. 598). - 
Anostomidae Leporellus vittatus (Valenciennes, 1850) Fr native  Piava (Portuguese), Piau rola (Portuguese), Piau-listrado (Portuguese), Solteira (Portuguese), Solteirinha (Portuguese)   30.00 cm SL male/unsexed  Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). Also Ref. 598, 36801. + 
Anostomidae Leporinus acutidens (Valenciennes, 1837) Fr native  Piava de três pintas (Portuguese)  33.00 cm TL male/unsexed  Known from the Amazon River (Ref. 36801). Present in the Oyapock River which forms the border between French Guiana and Brazil (Ref. 12225). - 
Anostomidae Leporinus affinis Günther, 1864 Fr, Fi, Or native  Piau-flamengo (Portuguese), Araçu flamenco (Portuguese), Aracu flamengo (Portuguese), Aracu pinima (Portuguese), Araçu pinima (Portuguese), Bargado (Portuguese), Camisa de meia (Portuguese), Caninana (Portuguese), Flamenguista (Portuguese), Piau aracu (Portuguese), Rajado (Portuguese)   30.00 cm TL male/unsexed  Known from the Amazon basin (Ref. 36801). Reported from Para (Ref. 598). Found in fish markets in Santarém (Ref. 12202). Type locality: Rio Parin. Also Ref. 1672. + 
Anostomidae Leporinus agassizii Steindachner, 1876 Fr native  Aracú (Portuguese), Piau (Portuguese)   23.40 cm SL male/unsexed  Known from the Amazon River (Ref. 36801). + 
Anostomidae Leporinus alternus Eigenmann, 1912 Fr native    Known from the Amazon River (Ref. 36801). - 
Anostomidae Leporinus amae Godoy, 1980 Fr native  Perna-de-moça (Portuguese), Boca-de-moça (Portuguese), Cara de fogo (Portuguese)  19.40 cm TL male/unsexed  Known from the Uruguay River basin (Ref. 36801). + 
Anostomidae Leporinus amazonicus Santos & Zuanon, 2008 Fr native    25.30 cm SL male/unsexed    - 
Anostomidae Leporinus amblyrhynchus Garavello & Britski, 1987 Fr native  Chimbore (Portuguese), Piau (Portuguese)   27.40 cm SL male/unsexed  Known from the Paraná River basin (Ref. 36801). Museum: Fazenda Pau d'Alho, Rio Tietê, Itu, Sao Paulo, MZUSP 14411 (holotype of L. amblyrhynchus, 12.5 cm SL) (Ref. 27925). + 
Anostomidae Leporinus aripuanaensis Garavello & dos Santos, 1981 Fr native   9.30 cm SL male/unsexed  Known from the Aripuanã River basin (Ref. 36801). Museum: Igarapé do Aeroporto, tributary of Rio Aripuana, Humboldt, Aripuana, Mato Grosso State, MZUSP 14495 (holotype to L. aripuanensis, 9.27 cm SL) (Ref. 27925). Also Ref. 46237. - 
Anostomidae Leporinus bahiensis Steindachner, 1875 Fr native  Piau (Portuguese)    Recorded from Bahia (Ref. 598). Also Ref. 36801. + 
Anostomidae Leporinus bimaculatus Castelnau, 1855 Fr native    Known from the Tocantins River basin (Ref. 36801). - 
Anostomidae Leporinus bistriatus Britski, 1997 Fr native   13.70 cm SL male/unsexed  Known from the Tocantins River basin (Ref. 36801). Type locality: Itacaiunas river, Igarape Aguas Claras, Caldeirao (Ref. 42606). - 
Anostomidae Leporinus bleheri Géry, 1999 Fr native   14.20 cm SL male/unsexed   - 
Anostomidae Leporinus britskii Feitosa, Santos & Birindelli, 2011 Fr native   10.04 cm male/unsexed  Found in rio Teles Pires and rio Jamanxim, rio Tapajós basin, and rio Jari, clearwater tributaries of the lower portion of the Amazon (Ref. 88850). - 
Anostomidae Leporinus brunneus Myers, 1950 Fr native  Uaracu piranga (Portuguese)  25.60 cm SL male/unsexed  Known from Rio Negro (Ref. 30270). Also Ref. 36801. + 
Anostomidae Leporinus cylindriformis Borodin, 1929 Fr native   19.86 cm SL male/unsexed  Known from the lower Amazon River basin (Ref. 36801). Type locality: Porto do Moz (Ref. 26282). Also Ref. 96869. - 
Anostomidae Leporinus desmotes Fowler, 1914 Fr native    22.00 cm TL male/unsexed    + 
Anostomidae Leporinus enyae Burns, Chatfield, Birindelli & Sidlauskas, 2017 Fr native    (southern tributaries of the Orinoco river drainage. including the Ventuari, Known from the upper Negro River and Casiquiare canal, which connects the Negro and Orinoco rivers (Ref. 119688). - 
Anostomidae Leporinus falcipinnis Mahnert, Géry & Muller, 1997 Fr endemic    Known from the lower Tapajós River basin (Ref. 36801). Type locality: Rio Arapiuns, 1 hr. by boat downstream of mouth of rio Arua, lower Tapajos basin, Para, Brazil, 2°04'S, 55°38'W (Ref. 26282). + 
Anostomidae Leporinus fasciatus (Bloch, 1794) Fr, Fi native  Aracú-flamengo (Portuguese), Aracu amarelo (Portuguese), Aracu flamengo (Portuguese), Aracu pinima (Portuguese), Ferreirinha (Portuguese), Piau flamengo (Portuguese)   37.00 cm TL male/unsexed  Known from the Amazon River (Ref. 36801). + 
Anostomidae Leporinus friderici (Bloch, 1794) Fr, Fi native  Piapara (Portuguese), Acaru paca (Portuguese), Aracu cabeça gorda (Portuguese), Araçu cabeça gorda (Portuguese), Aracu comum (Portuguese), Piaba (Portuguese), Piau (Portuguese), Piau cabeça-gorda (Portuguese), Piau listrado (Portuguese), Piau três pintas (Portuguese), Piava (Portuguese), Uaracu (Portuguese) scarce (very unlikely) 40.00 cm SL male/unsexed 13.1 TL Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076), Pircacicaba river (Ref. 50076) and Machado river (Ref. 97589). Also Ref. 31923. + 
Anostomidae Leporinus geminis Garavello & Santos, 2009 Fr native   18.00 cm SL male/unsexed  Found in the Rio Tocantins (Ref. 80692). + 
Anostomidae Leporinus gomesi Garavello & Santos, 1981 Fr native   16.00 cm SL male/unsexed  Known from the Aripuanã River basin (Ref. 36801). Museum: Rio Aripuana above the Cachoeira de Dardanelos, Humboldt, Aripuana, Mato Grosso State, MZUSP 14436 (holotype of L. gomesi, 15 cm SL) (Ref. 27925). Also Ref. 46237. - 
Anostomidae Leporinus guttatus Birindelli & Britski, 2009 Fr native   12.47 cm SL male/unsexed  Found in the upper rio Curuá (above the great falls of Serra do Cachimbo), a tributary of the rio Iriri, rio Xingu in Pará State. Its absence below the waterfalls suggests that this species might be restricted to the river portion isolated above the falls (Ref. 80699). - 
Anostomidae Leporinus jamesi Garman, 1929 Fr native    15.49 cm SL male/unsexed  Known from the rio Amazonas, rio Solimões, rio Madeira and lower portion of their tributaries at the central Amazonian region (Ref. 96869). Also Ref. 36801. - 
Anostomidae Leporinus klausewitzi Géry, 1960 Fr native    Known from central Amazon River basin (Ref. 36801). Type locality: Mundurucú, Rio Manacapuru, Amazon basin, near Manaos, Brazil (Ref. 26282). + 
Anostomidae Leporinus lacustris Amaral Campos, 1945 Fr, Fi native  Piava de lagoa (Portuguese), Piau (Portuguese)   24.00 cm TL male/unsexed 8.4 TL Known from Paraná River basin (Ref. 36801). Found in Piracicaba river (Ref. 50076). Museum: Pirassununga, Estado de Sao Paulo, MZUSP 3458 (holotype of L . Lacustris, 11.1 cm SL) (Ref. 27925). Also Ref. 598. + 
Anostomidae Leporinus leschenaulti Valenciennes, 1850 Fr native    Known from coastal rivers in northern Brazil (Ref. 36801). + 
Anostomidae Leporinus maculatus Müller & Troschel, 1844 Fr, Thr native  Araçu pinima (Portuguese), Piau (Portuguese), Timboré pichó (Portuguese), Ximburé (Portuguese)   18.00 cm TL male/unsexed ;20.00 cm TL female  Known from São Francisco River basin (Ref. 36801). Regarded as threatened in the state of Minas Gerais (Ref. 26603). + 
Anostomidae Leporinus marcgravii Lütken, 1875 Fr native  Piau (Portuguese), Timboré (Portuguese)  11.85 cm SL male/unsexed  Known from São Francisco River basin (Ref. 36801). + 
Anostomidae Leporinus melanopleura Günther, 1864 Fr, Thr native  Piau (Portuguese), Piau de coco (Portuguese)    Known from Cipó River basin in Bahia (Ref. 36801). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 598. - 
Anostomidae Leporinus melanopleurodes Birindelli, Britski & Garavello, 2013 Fr native   12.87 cm SL male/unsexed  Found in rio das Almas and rio Jiquiriçá, two small coastal river in southern Bahia (Ref. 93224). - 
Anostomidae Leporinus melanostictus Norman, 1926 Fr native  Araçu (Portuguese)  28.00 cm SL male/unsexed  Present in the Oyapock River which forms the border between Brazil and French Guiana (Ref. 12225). Also Ref. 36801. + 
Anostomidae Leporinus microphthalmus Garavello, 1989 Fr, Thr native    11.80 cm SL male/unsexed  Known from Paraná River basin (Ref. 36801). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Museum: Rio Araguari, salto de Nova Ponte, Nova Ponte, Estado de Minas Gerais, MZUSP 38535 (holotype of L. microphthalmus, 8.7 cm SL) (Ref. 27925). - 
Anostomidae Leporinus microphysus Birindelli & Britski, 2013 Fr native   12.88 cm SL male/unsexed  Type locality of Leporinus microphysus from Laranjal do Jari, Rio Iratapuru, tributary of Rio Jari, at Cachoeira Sao Raimundo, Amapa, Brazil, MZUSP 111001. Also known from Rio Iratapuru, a tributary of the Rio Jari, above Cachoeira do Santo Antonio and tributaries of the Rio Tapajos, including the Rio Teles Pires and the Rio Jamanxim, in the states of Mato Grosso and Para (Ref. 128920). - 
Anostomidae Leporinus moralesi Fowler, 1942 Fr native  Aracu autã (Portuguese)  30.00 cm TL male/unsexed  Known from the Amazon River (Ref. 36801). + 
Anostomidae Leporinus multimaculatus Birindelli, Teixeira & Britski, 2016 Fr native   11.06 cm SL male/unsexed  Known from the small tributaries at the rio Araguaia, rioTocantins and rio Xingu basins in Goiás, Mato Grosso, Pará and Tocantins states; rio Jari basin and coastal drainages of Amapá state (Ref. 117595). Status of threat: Least Concern (LC) (Ref. 117595). - 
Anostomidae Leporinus nattereri Steindachner, 1876 Fr native    Known from Negro River, Aleixo Lake, central Amazon basin (Ref. 36801). - 
Anostomidae Leporinus nigrotaeniatus (Jardine, 1841) Fr native  Biri biri (Portuguese), Uaracu murutinga (Portuguese)  40.00 cm TL male/unsexed  Found in the Negro River basin (Ref. 36801). + 
Anostomidae Leporinus nijsseni Garavello, 1990 Fr native   17.00 cm TL male/unsexed  Present in the Oyapock River which forms th border between Brazil and French Guiana (Ref. 12225). Also Ref. 36801. + 
Anostomidae Leporinus octofasciatus Steindachner, 1915 Fr native  Ferreirinha (Portuguese), Piau listrado (Portuguese), Piava (Portuguese), Salmo ferreiro (Portuguese)   31.20 cm SL male/unsexed  Known from the northern Cubatão River in Santa Catarina and upper Paraná River basin (Ref. 36801). Also Ref. 598. + 
Anostomidae Leporinus octomaculatus Britski & Garavello, 1993 Fr native   12.90 cm SL male/unsexed  Known from the Arinos River basin in Tapajós River drainage (Ref. 36801). Museum: MZUSP 44794 (holotype of L. octomaculatus, 6.85 cm SL) (Ref. 27925). + 
Anostomidae Leporinus ortomaculatus Garavello, 2000 Fr native   7.80 cm SL male/unsexed  Known from the Negro River (Ref. 36801). + 
Anostomidae Leporinus pachyurus Valenciennes, 1850 Fr native    Occurs in the Amazon River basin (Ref. 36801). - 
Anostomidae Leporinus parae Eigenmann, 1907 Fr native    22.90 cm SL male/unsexed  Known from the river basins of Pará, lower Amazon (Ref. 36801) and Acre (Ref. 97592). - 
Anostomidae Leporinus paralternus Fowler, 1914 Fr native    Known from the Amazon River (Ref. 36801). - 
Anostomidae Leporinus paranensis Garavello & Britski, 1987 Fr, Fi native    16.00 cm SL male/unsexed  Known from the Paraná River basin (Ref. 36801). Found in Piracicaba river (Ref. 50076). Museum: Marimbondo, Rio Grande, Sao Paulo, MZUSP 14453 (holotype of L. paranensis, 15.4 cm SL) (Ref. 27925). - 
Anostomidae Leporinus parvulus Birindelli, Britski & Lima, 2013 Fr native   7.68 cm SL male/unsexed  Found in two sites in the the Rio Tapajós, Pederneiras and São Luiz, which are immediately below and a few kilometers upriver of the city of Itaituba in Pará (Ref. 93868). - 
Anostomidae Leporinus pellegrinii Steindachner, 1910 Fr native   12.00 cm TL male/unsexed  Known from the upper Amazon (Ref. 598, 36801). + 
Anostomidae Leporinus piau Fowler, 1941 Fr native  Piau (Portuguese), Piau gordura (Portuguese), Piau verdadeiro (Portuguese)   33.02 cm FL male/unsexed  Known from Salgado, Ceará (Ref. 36801). + 
Anostomidae Leporinus pitingai Santos & Jégu, 1996 Fr native   31.50 cm SL male/unsexed  Known from the Pitinga River, Amazonas (Ref. 36801). Type locality: Rio Pitinga, Cachoeira 40 Ilhas, Amazonas (Ref. 42606). - 
Anostomidae Leporinus reticulatus Britski & Garavello, 1993 Fr native   13.59 cm SL male/unsexed  Known from the Arinos and Tapajós River basins (Ref. 36801). Museum: headwaters of the Rio Arinos, Rio Tapajós basin, Mato Grosso, MZUSP 44781 (holotype of L. reticulatus, 6.62 cm SL ) (Ref. 26282, 27925). - 
Anostomidae Leporinus santosi Britski & Birindelli, 2013 Fr native   13.50 cm SL male/unsexed  Found in a tributary of the rio Tocantins, at the stretch now inundated by the Tucuruí reservoir, and a tributary of the rio Itacaiúnas, a large tributary of the lower rio Tocantins (Ref. 93223). - 
Anostomidae Leporinus sexstriatus Britski & Garavello, 1980 Fr native   8.00 cm SL male/unsexed  Known from Papagaio and Tapajós River basins (Ref. 36801). Museum: Rio Papagaio, acima de Salto de Utiariti, Mato Grosso, MZUSP 9232 (holotype of L. sexstriatus, 7 cm SL) (Ref. 27925). - 
Anostomidae Leporinus spilopleura Norman, 1926 Fr native   26.50 cm SL male/unsexed   - 
Anostomidae Leporinus striatus Kner, 1858 Fr, Fi native  Canivete (Portuguese), Ferreirinha (Portuguese), Piau (Portuguese), Piava (Portuguese), Riscadinho (Portuguese), Tanchina (Portuguese), Taxina (Portuguese)   25.00 cm TL male/unsexed  Found in Piracicaba river (Ref. 50076) and Uruguay River (Ref. 79585). Also Ref. 598. + 
Anostomidae Leporinus taeniatus Lütken, 1875 Fr native  Piau (Portuguese), Piau jejo (Portuguese), Piau jeju (Portuguese), Timburé (Portuguese)   19.00 cm TL male/unsexed  Known from Das Velhas and São Francisco River basins (Ref. 36801). Type locality : Rio das Velhas, Minas Gerais, Brazil (Ref. 26282). + 
Anostomidae Leporinus taeniofasciatus Britski, 1997 Fr native   27.80 cm SL male/unsexed ;31.50 cm SL female  Known from the Tocantins River basin (Ref. 36801). Type locality: Maranhao river, Barro Alto and Niquelandia (Ref. 42606). - 
Anostomidae Leporinus tigrinus Borodin, 1929 Fr native    22.00 cm SL male/unsexed ;29.80 cm SL female  Known from the Tocantins River basin (Ref. 36801). + 
Anostomidae Leporinus torrenticola Birindelli, Teixeira & Britski, 2016 Fr native   14.50 cm TL male/unsexed  Occurs in the rapids of the middle rio Xingu and its main tributaries, the rio Iriri and rio Curuá in Pará state. The construction of hydroelectiirc dam Belo Monte modified part of the rapids of the rio Xingu. The impacts of this dam to the population of Leporinus torrenticola need to be assessed (Ref. 117595). Status of threat: Data Deficient (DD) (Ref. 117595). - 
Anostomidae Leporinus trimaculatus Garavello & Santos, 1992 Fr native   23.20 cm SL male/unsexed  Known from the Aripuanã River basin (Ref. 36801). Museum: Rio Aripuana, Humboldt, Aripuana, Mato Grosso State, Amazonia, MZUSP 14459 (holotype of L. trimaculatus, 19.5 cm SL) (Ref. 27925). Also Ref. 46237. - 
Anostomidae Leporinus tristriatus Birindelli & Britski, 2013 Fr native   10.10 cm SL male/unsexed  Type locality of Leporinus tristriatus from Peixoto de Azevedo, tributary of Rio Peixoto de Azevedo, at Cachoeira da Neblina, Rio Teles Pires basin, Mato Grosso, Brazil, MZUSP 96800. Also known from tributaries of the upper Rio Tocantins, upper Rio Xingu and the Rio Tapajos, including the Rio Arinos, the Rio Teles Pires and the Rio Jamanxim, in the states of Goias, Mato Grosso and Para (Ref. 128920). - 
Anostomidae Leporinus uatumaensis Santos & Jégu, 1996 Fr native   10.20 cm SL male/unsexed  Known from the Uatumã River basin (Ref. 36801). Type locality: Rio Uatumã, Cachoeira do Miriti, abaixo da cachoeira Balbina, Amazonas (Ref. 42606). - 
Anostomidae Leporinus unitaeniatus Garavello & Santos, 2009 Fr native   12.50 cm SL male/unsexed  Known from the Araguaia and Tocantins rivers (Ref. 80692). - 
Anostomidae Leporinus vanzoi Britski & Garavello, 2005 Fr native    Known from the Rio Araguaia (Ref. 75002). - 
Anostomidae Leporinus venerei Britski & Birindelli, 2008 Fr native   13.55 cm SL male/unsexed  Found only in the rio Araguaia basin in Mato Grosso and Goiás states, central Brazil (Ref. 75002). - 
Anostomidae Leporinus villasboasorum Burns, Chatfield, Birindelli & Sidlauskas, 2017 Fr native   12.79 cm SL male/unsexed  Type locality of Leporinus villasboasorum, Mato Grosso, Campinápolis, rio Culuene, tributary of rio Xingu, at cofferdam of PCH Paranatinga 2. Known from the Mato Grosso State: throughout the middle and upper Xingu drainage, from Volta Grande rapids near Belo Monte, downstream of the city of Altamira in Pará State to the headwaters of the Xingu River in Mato Grosso State and in the tributaries of the upper Tapajós River, the Teles Pires and Juruena rivers (Ref. 119688). + 
Callichthyidae Lepthoplosternum beni Reis, 1997 Fr native    5.00 cm SL male/unsexed   + 
Callichthyidae Lepthoplosternum pectorale (Boulenger, 1895) Fr native  Tamoatá (Portuguese), Camboatá (Portuguese), Tamboatá (Portuguese)   6.03 cm SL male/unsexed  Recorded from the Rio Paraguay (Ref. 26144). Also Ref. 37395, 81048. + 
Callichthyidae Lepthoplosternum stellatum Reis & Kaefer, 2005 Fr native   4.58 cm SL male/unsexed  Type locality, Igarapé Repartimento, a tributary of the mouthbay lake, Lago Tefé, some 6 kilometers south of the town of Tefé, Amazonas. - 
Callichthyidae Lepthoplosternum tordilho Reis, 1997 Fr native  Cascudo (Portuguese), Tamoatá (Portuguese)   4.58 cm SL male/unsexed  Known from the northern tributaries of Laguna dos Patos in southern Brazil (Ref. 37395). Recorded from Rio Grande do Sul (Ref. 26144). Also Ref. 33172, 56211. - 
Callichthyidae Lepthoplosternum ucamara Reis & Kaefer, 2005 Fr native   4.55 cm SL male/unsexed  Known from the area of confluence of the Rio Solimões and Rio Japurá. - 
Characidae Leptobrycon jatuaranae Eigenmann, 1915 Fr native   2.90 cm male/unsexed  Found in the Amazon River basin (Ref. 38376). Type locality: Jatuarana, Amazon R., Brazil. - 
Doradidae Leptodoras acipenserinus (Günther, 1868) Fr native  Mandi-serra (Portuguese)   20.30 cm SL male/unsexed  Known from the Amazon basin (Ref. 56896). + 
Doradidae Leptodoras cataniai Sabaj Pérez, 2005 Fr native   19.40 cm SL male/unsexed  Known from rio Negro of the Amazonas drainage (Ref. 56896). + 
Doradidae Leptodoras copei (Fernández-Yépez, 1968) Fr native  Botinho (Portuguese)   14.20 cm SL male/unsexed    + 
Doradidae Leptodoras hasemani (Steindachner, 1915) Fr native   22.80 cm TL male/unsexed  Found in the mouth of Rio Negro, in Rio Branco at Boa Vista and Serra Grande (Ref. 6868). Also found in the lower rio Demini, a tributary of the rio Negro (Ref. 56896). Two large adults were recently collected in the rio Jamanxim in the middle Tapajós, extending the range of this species to the Brazilian Shield (Ref. 79526). + 
Doradidae Leptodoras juruensis Boulenger, 1898 Fr native  Reco (Portuguese)   28.80 cm SL male/unsexed  Known from the Amazon basin (Ref. 56896). Also Ref. 6868. + 
Doradidae Leptodoras linnelli Eigenmann, 1912 Fr native  Mandi-serra (Portuguese)   23.00 cm SL male/unsexed  Known from rios Araguari, Demini, Negro, Pitinga and Tacutu (Ref. 56896). Recently collected from the rio Tiquié basin (right bank tributary of the upper rio Negro) in the Amazonas State and from the upper rio Aripuaña (tributary of the rio Madeira) in Mato Grosso State. This represents an extension of the known distribution of this species into the western limits of the Brazilian Shield (Ref. 79526). + 
Doradidae Leptodoras marki Birindelli & Sousa, 2010 Fr native   9.25 cm SL male/unsexed   - 
Doradidae Leptodoras myersi Böhlke, 1970 Fr native    7.70 cm SL male/unsexed   + 
Doradidae Leptodoras oyakawai Birindelli, Sousa & Sabaj Pérez, 2008 Fr native   12.35 cm SL male/unsexed  Found in rio Jamanxim (type series) and rio Teles Pires, rio Tapajós basin, and rio Culuene and rio Curisevo, upper rio Xingu basin (Ref. 79526). - 
Doradidae Leptodoras praelongus (Myers & Weitzman, 1956) Fr native  Botinho (Portuguese), Cuyú cuyú (Portuguese)   18.50 cm SL male/unsexed  Known from the Madeira, Negro and Amazon river drainages; also Tocantins River (Ref. 56896). Also Ref. 6868. + 
Rivulidae Leptolebias aureoguttatus (da Cruz, 1974) Fr native   4.00 cm TL male/unsexed   + 
Rivulidae Leptolebias citrinipinnis (Costa, Lacerda & Tanizaki, 1988) Fr native    5.00 cm TL male/unsexed  Museum: pool in Maricá, Estado do Rio de Janeiro, MZUSP 37199 (holotype) (Ref. 36579). + 
Rivulidae Leptolebias itanhaensis Costa, 2008 Fr, Thr native    2.17 cm SL male/unsexed  Known from the seasonal pools in the Itanhaém river basin in São Paulo State, southeastern Brazil (Ref. 75888). This area is undergoing slight urbanization, endangering this species (Ref. 75888). + 
Rivulidae Leptolebias marmoratus (Ladiges, 1934) Fr, Fi, Or endemic    3.00 cm TL male/unsexed  Found in temporary pools close to streams of river basins draining into northern baía de Guanabara, including rio Iguaçú and rio Estrela basins. In recent survey encompassing the whole geographic range, this species is critically endangered (Ref. 50094). Possibly extinct in the wild (Ref. 27139). Also Ref. 3881, 36579. - 
Rivulidae Leptolebias opalescens (Myers, 1942) Fr, Fi, Or endemic   4.00 cm TL male/unsexed  Found in Rio de Janeiro. - 
Rivulidae Leptolebias splendens (Myers, 1942) Fr, Fi, Or endemic    3.00 cm TL male/unsexed  Known from Rio de Janeiro. - 
Eleotridae Leptophilypnion fittkaui Roberts, 2013 Fr native   0.95 cm SL male/unsexed  Type locality of Leptopphilypnion fittkaui from Rio Negro watershed, Rio Cuieiras, Igarapé Cachoeira at Cachoeira Pedras dos Indios, Amazonas, Brazil, ZSM 42249 (Ref. 93348). - 
Eleotridae Leptophilypnion pusillus Roberts, 2013 Fr native   0.91 cm SL male/unsexed  Type locality of Leptophilypnion pusillus from the right bank of lower part of igarapé tributary to Rio Tapajós bordering city of Santarém, MZUSP 40297 (Ref. 93348). - 
Heptapteridae Leptorhamdia essequibensis (Eigenmann, 1912) Fr native   16.00 cm SL male/unsexed  Known from the lower Tocantins River basin (Ref. 36914). + 
Heptapteridae Leptorhamdia marmorata Myers, 1928 Fr native   12.80 cm SL male/unsexed  Found in the Negro River basin (Ref. 6868, 36914). - 
Heptapteridae Leptorhamdia schultzi (Miranda Ribeiro, 1964) Fr native   9.40 cm SL male/unsexed  Known from the upper Xingu River basin (Ref. 36914). + 
Loricariidae Leptotocinclus ctenistus Delapieve, Lehmann A & Reis, 2018 Fr native  abundant (always seen in some numbers) 3.06 cm SL male/unsexed  Found in the tributaries to the rio Solimões and rio Negro (Ref. 116855). Status of threat: Least Concern (LC) (Ref. 116855). - 
Loricariidae Leptotocinclus madeirae Delapieve, Lehmann A & Reis, 2018 Fr native   3.06 cm SL male/unsexed  Known from the tributaries to the middle rio Madeira and Purus (Ref. 116855). - 
Triportheidae Lignobrycon myersi (Miranda Ribeiro, 1956) Fr native  Canivete (Portuguese), Mossarupè (Portuguese), Piaba-faca (Portuguese)   8.48 cm SL male/unsexed  Museum: Rio do Braço, Bahia, 2 km SW of town of Rio do Braço, USNM 304497. Also Ref. 38376. - 
Loricariidae Limatulichthys griseus (Eigenmann, 1909) Fr native  Bode cachimbo (Portuguese), Uacari (Portuguese)   23.70 cm TL male/unsexed    + 
Auchenipteridae Liosomadoras oncinus (Jardine, 1841) Fr native   17.00 cm TL male/unsexed  Known from Branco River basin (Ref. 37098). + 
Trichomycteridae Listrura boticario de Pinna & Wosiacki, 2002 Fr native   3.70 cm SL male/unsexed  Known from Da Figueira and Guaraqueçaba River basins (Ref. 39970). - 
Trichomycteridae Listrura camposi (Miranda Ribeiro, 1957) Fr native  Bagre mole (Portuguese), Candiru (Portuguese)   3.94 cm SL male/unsexed  Known from Poço Grande River, tributary of the Juquiá River, São Paulo and Ribeirão da Ilha, Florianópolis, Santa Catarina (Ref. 39970). - 
Trichomycteridae Listrura costai Villa-Verde, Lazzarotto & Lima, 2012 Fr, Br, Thr native   3.43 cm SL male/unsexed  Know from two neighboring small unnamed coastal streams draining into a swampy portion of the rio Jurumirim, close to its mouth, in Angra dos Reis Municipality, Rio de Janeiro State. Vulnerable of becoming critically endangered or even extinct in a very short time period due to effects of human activities or stochastic events (Ref. 91744). - 
Trichomycteridae Listrura depinnai Villa-Verde, Ferrer & Malabarba, 2014 Fr native   3.08 cm SL male/unsexed  Known from a swamp on the wildlife reserve Refúgio de Vida Silvestre Banhado dos Pachecos, Rio Gravataí basin, Laguna dos Patos system (Ref. 94748). - 
Trichomycteridae Listrura nematopteryx de Pinna, 1988 Fr native    3.66 cm SL male/unsexed  Found in marsh that is the source of a creek later joining Imbariê Creek, tributary of the Estrela River, Piabetá, Rio de Janeiro, and similar habitats in Picinguaba, São Paulo (Ref. 39970). + 
Trichomycteridae Listrura picinguabae Villa-Verde & Costa, 2006 Fr native   4.86 cm SL male/unsexed  Known from small tributary streams of rio da Fazenda, an isolated coastal river in Picinguaba, São Paulo State, southeastern Brazil (Ref. 57477). - 
Trichomycteridae Listrura tetraradiata Landim & Costa, 2002 Fr native    4.44 cm SL male/unsexed  Type locality, about 5 km north from Bacaxá, Palmital, rio Ibicuíba basin of the Lagoa de Araruama system, tributary of rio Bom Sucesso, rio da Represa, Município de Saquarema, Estado do Rio de Janeiro (Ref. 41513). Also Ref. 39970. - 
Doradidae Lithodoras dorsalis (Valenciennes, 1840) Fr, Fi native  Pacú (Portuguese), Bacu (Portuguese), Bacu de pedra (Portuguese), Bacu pedra (Portuguese), Cascudo (Portuguese), Daqueiro (Portuguese), Pacu (Portuguese), Vacu (Portuguese), Vacú (Portuguese)   100.00 cm TL male/unsexed  Known from the Amazon River (Ref. 37054). Found in fish markets in Santarém (Ref. 12202). + 
Acestrorhynchidae Lonchogenys ilisha Myers, 1927 Fr native   8.00 cm TL male/unsexed  Known from the Negro River basin (Ref. 36811). + 
Characidae Lophiobrycon weitzmani Castro, Ribeiro, Benine & Melo, 2003 Fr endemic   2.89 cm SL male/unsexed ;2.73 cm SL female  Known only from the type locality: upper Paraná River basin, Rio Grande basin; Município de Delfinópolis, Estância Carmen Sílvia, córrego Bom Jesus (20°12'10"S; 46°55'22"W). Specimens caught in winter 1998 and 1999 (Ref. 52251). - 
Pseudopimelodidae Lophiosilurus alexandri Steindachner, 1876 Fr, Fi, Thr endemic  Pacamão (Portuguese), Bagre sapo (Portuguese), Cururu (Portuguese), Pacamã (Portuguese), Pacamon (Portuguese), Peixe sapo (Portuguese), Piacururu (Portuguese), Piracururu (Portuguese)   72.00 cm TL male/unsexed  Known from São Francisco River basin (Ref. 39418). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 6868. + 
Loricariidae Loricaria apeltogaster Boulenger, 1895 Fr native   32.40 cm SL male/unsexed   - 
Loricariidae Loricaria birindellii Thomas & Sabaj Pérez, 2010 Fr native   36.50 cm TL male/unsexed   + 
Loricariidae Loricaria cataphracta Linnaeus, 1758 Fr native  Acari (Portuguese), Aacarí (Portuguese), Acarí (Portuguese), Acari cachimbo (Portuguese), Acarí cachimbo (Portuguese), Bode cachimbo (Portuguese), Cachimbo (Portuguese), Cari chicote (Portuguese), Pilote (Portuguese)   29.50 cm SL male/unsexed  Known from the Amazon (Ref. 36389) and Machado River basins (Ref. 97589). + 
Loricariidae Loricaria clavipinna Fowler, 1940 Fr native   18.00 cm SL male/unsexed  Known from the Amazon River (Ref. 36389). - 
Loricariidae Loricaria coximensis Rodriguez, Cavallaro & Thomas, 2012 Fr native   9.36 cm SL male/unsexed  Found only in a riffle in the Rio Coxim and a first order tributary within 500 meters from the powerhouse of the Ponte Alta Hydroelectric facility, municipality of São Gabriel do Oeste, Mato Grosso do Sul State (Ref. 90156). - 
Loricariidae Loricaria lata Eigenmann & Eigenmann, 1889 Fr native   27.00 cm SL male/unsexed  Known from Rio Araguaia drainage in Goiás (Ref. 6868). + 
Loricariidae Loricaria lentiginosa Isbrücker, 1979 Fr native    51.40 cm SL male/unsexed  Known from the Paraná River (Ref. 36389). - 
Loricariidae Loricaria luciae Thomas, Rodriguez, Carvallaro, Froehlich & Macedo Corrêa e Castro, 2013 Fr native   18.91 cm SL male/unsexed  Known from the rio Paraguay basin (Ref. 94550). + 
Loricariidae Loricaria lundbergi Thomas & Rapp Py-Daniel, 2008 Fr native   13.81 cm SL male/unsexed  Known from the rio Negro system (Ref. 79031). - 
Loricariidae Loricaria parnahybae Steindachner, 1907 Fr native  Cascudo (Portuguese)   16.00 cm SL male/unsexed    + 
Loricariidae Loricaria piracicabae Ihering, 1907 Fr native  Cascudo espada (Portuguese)  17.00 cm SL male/unsexed  Known from the Piracicaba River basin (Ref. 36389). - 
Loricariidae Loricaria pumila Thomas & Rapp Py-Daniel, 2008 Fr native   8.10 cm SL male/unsexed  Found in the Rio Amazonas near the mouth of rio Tapajós and rio Pará adjacent to and including lower rio Tocantins (Ref. 79031). - 
Loricariidae Loricaria simillima Regan, 1904 Fr native    26.40 cm SL male/unsexed    + 
Loricariidae Loricaria spinulifera Thomas & Rapp Py-Daniel, 2008 Fr native   13.77 cm SL male/unsexed  Found in the Rio Negro and in the lower rio Branco downstream to the mouth of the rio Negro, including the lower rio Jauaperi (Ref. 79031). - 
Loricariidae Loricariichthys acutus (Valenciennes, 1840) Fr native    28.00 cm SL male/unsexed    - 
Loricariidae Loricariichthys anus (Valenciennes, 1835) Fr native  Cascudo-chicote (Portuguese), Cascudo viola (Portuguese), Viola (Portuguese)  46.00 cm male/unsexed  Recorded from the Patos lagoon (Ref. 58359) and the Uruguay River (Ref. 79585). Also Ref. 36389. + 
Loricariidae Loricariichthys castaneus (Castelnau, 1855) Fr native    39.60 cm TL male/unsexed  Found in coastal streams of southeastern Brazil between southern São Paulo and northern Espírito Santo, including the Paraíba do Sul River basin (Ref. 36389). + 
Loricariidae Loricariichthys derbyi Fowler, 1915 Fr native    24.90 cm TL male/unsexed  Known from the Jaguaribe River basin (Ref. 36389). + 
Loricariidae Loricariichthys labialis (Boulenger, 1895) Fr native  Cari (Portuguese), Acari (Portuguese), Cascudo viola (Portuguese), Rapa-canoa (Portuguese)   22.00 cm SL male/unsexed    - 
Loricariidae Loricariichthys maculatus (Bloch, 1794) Fr native    26.30 cm SL male/unsexed    + 
Loricariidae Loricariichthys melanocheilus Reis & Pereira, 2000 Fr native   43.00 cm SL male/unsexed  Known from the Paraná and Uruguay River basins (Ref. 36389). - 
Loricariidae Loricariichthys nudirostris (Kner, 1853) Fr native  Cachimbinho (Portuguese), Cachimbo (Portuguese), Foguete (Portuguese), Jotoxi (Portuguese)   23.50 cm SL male/unsexed  Found in the Amazon River basin (Ref. 36389). - 
Loricariidae Loricariichthys platymetopon Isbrücker & Nijssen, 1979 Fr native  Acari (Portuguese), Cari (Portuguese), Rapa-canoa (Portuguese)   38.30 cm TL male/unsexed ;39.00 cm TL female 14.5 TL   + 
Loricariidae Loricariichthys rostratus Reis & Pereira, 2000 Fr native    27.50 cm SL male/unsexed  Known from the Paraná River (Ref. 36389). + 
Pimelodidae Luciopimelodus pati (Valenciennes, 1835) Fr, Fi native  Pati (Portuguese), Morre morre (Portuguese), Piracatinga (Portuguese)  103 cm TL male/unsexed  Found in the Uruguay River (Ref. 79585). + 
Blenniidae Lupinoblennius paivai (Pinto, 1958) Fr, Br native  Paiva's blenny (English)  5.07 cm SL male/unsexed  Found in Rio Mococa, Rio Claro, and Rio Escuro (Ref. 49399). + 
Engraulidae Lycengraulis batesii (Günther, 1868) Fr, Br native  Sardinha-dogato (Portuguese), Arem (Portuguese), Arenque (Portuguese), Arenque-boca-de-velho (Portuguese), Arenque-boca-larga (Portuguese), Cachorro (Portuguese), João duro (Portuguese), Maiaca (Portuguese), Maiacá (Portuguese), Manjuba (Portuguese), Peixe-cachorro (Portuguese), Sardinha (Portuguese), Sardinha de boto (Portuguese), Sardinha de lata (Portuguese), Sardinha fedorenta (Portuguese), Sardinha-do-gato (Portuguese)   30.00 cm TL male/unsexed    + 
Engraulidae Lycengraulis figueiredoi Loeb & Alcântara, 2013 Fr native   17.10 cm SL male/unsexed  Found only in the lago Castro and lago Beruri, in the drainage of rio Purus; rio Negro; lago José Açu at Parintins; lago Jacupá and rio Trombetas at Oriximiná, middle Amazon basin, Amazonas and Pará State (Ref. 93939) - 
Engraulidae Lycengraulis grossidens (Spix & Agassiz, 1829) Fr, Br, M native  Sardinha prata (Portuguese), Arem (Portuguese), Arenga-branca (Portuguese), Arenque (Portuguese), Arenque-amarelo (Portuguese), Arenque-branco (Portuguese), Arenque-do-dia (Portuguese), Comidiu (Portuguese), Manjuba (Portuguese), Manjubao (Portuguese), Manjubão (Portuguese), Mussolina (Portuguese), Mussulina (Portuguese), Pitinga (Portuguese), Sardinha manjuba (Portuguese), Sardinha plata (Portuguese), Sardinha preta (Portuguese), Sardinha-arenque (Portuguese), Sardinha-boca-de-cobra (Portuguese), Sardinha-branca (Portuguese), Sardinha-prata (Portuguese)  23.50 cm SL male/unsexed 8 TL Located at the southernmost tip of the Bombinhas peninsula, southern Brazil (Ref. 55758). Also Ref. 27363, 101685. + 
Characidae Macropsobrycon uruguayanae Eigenmann, 1915 Fr native  Lambari (Creole, Portuguese)  4.60 cm TL male/unsexed  Recorded from the Patos lagoon (Ref. 58359). - 
Characidae Macropsobrycon xinguensis Géry, 1973 Fr native  Piabinha (Creole, Portuguese)  3.21 cm SL male/unsexed  Known from the Xingu River basin (Ref. 48602). - 
Characidae Makunaima guaporensis (Eigenmann, 1911) Fr native    Found in the Guaporé River basin (Ref. 38376). - 
Characidae Makunaima guianensis (Eigenmann, 1909) Fr native   6.00 cm TL male/unsexed  Reported from Brazil, Pará, rio Xingu, vinicity of campsite 11 on downstream end of public beach along right bank, ca. 3 km downstream of Porto de Moz (Ref. 100733). + 
Characidae Makunaima multidens (Eigenmann, 1908) Fr native    Found in the Amazon River basin (Ref. 38376); at rio Amazonas at Silves, State of Amazonas, and Óbidos, State of Pará, and the rios Trombetas, Tapajós, Xingú and Araguaia (Ref. 93658). - 
Rivulidae Maratecoara formosa Costa & Brasil, 1995 Fr endemic    5.00 cm TL male/unsexed  Found in seasonal lagoons in the middle rio Tocantins floodplains in a typical savannah area (Ref. 57947). Also Ref. 27139, 36579. + 
Rivulidae Maratecoara gesmonei Nielsen, Martins & Britzke, 2014 Fr endemic    2.34 cm SL male/unsexed ;2.45 cm SL female  Currently only known from the type-locality, a temporary pool at an island from middle rio Xingu, Amazon basin, Pará state (Ref. 95615). - 
Rivulidae Maratecoara lacortei (Lazara, 1991) Fr endemic   5.00 cm TL male/unsexed  Known from Araguaia-das Mortes river basin, in typical savannah areas or transitional region between savannah and the Amazonian forest (Ref. 57947). + 
Rivulidae Maratecoara splendida Costa, 2007 Fr native   3.19 cm SL male/unsexed ;2.51 cm SL female  Found only in a seasonal lagoon near rio Canabrava of the rio Tocantins basin in a savannah region (Ref. 57947). - 
Characidae Markiana nigripinnis (Perugia, 1891) Fr native  Lambari-campo (Portuguese)   10.40 cm SL male/unsexed    + 
Heptapteridae Mastiglanis asopos Bockmann, 1994 Fr native  Bagrinho (Portuguese), Mandizinho (Portuguese)   6.60 cm SL male/unsexed  Known from Amazon and Capim River basins (Ref. 36914). Type locality: Igarapé Saracazinho, trib. of Rio Trombetas, near Porto Trombetas, Pará, Brazil (Ref. 26282). + 
Apteronotidae Megadontognathus kaitukaensis Campos-da-paz, 1999 Fr native   16.00 cm TL male/unsexed  Museum: Cachoeiras de Kaituká (=Caitucá), Rio Xingu, Pará State, INPA 14074 (holotype of M. kaitukaensis, 16 cm TL) (Ref. 33371). Also Ref. 36886. - 
Loricariidae Megalancistrus barrae (Steindachner, 1910) Fr endemic    38.50 cm SL male/unsexed  Known from São Francisco River basin (Ref. 36713). Also Ref. 6868. + 
Loricariidae Megalancistrus parananus (Peters, 1881) Fr native  Cascudo-abacaxi (Portuguese), Cascudo (Portuguese)   58.80 cm SL male/unsexed 14 TL   + 
Callichthyidae Megalechis picta (Müller & Troschel, 1849) Fr native  Tamboatá (Portuguese), Tamoatá (Portuguese), Tamuata (Portuguese)   17.00 cm SL male/unsexed  Recorded from the Amazon (Ref. 26144) and Machado River basins (Ref. 97589). + 
Callichthyidae Megalechis thoracata (Valenciennes, 1840) Fr native  Tamoatá (Portuguese), Atipa (Portuguese), Camboatá (Portuguese), Cambuí (Portuguese), Cascudo (Portuguese), Eloí (Portuguese), Sete léguas (Portuguese), Tamatá (Portuguese), Tamboatá (Portuguese), Tamuatá (Portuguese)   15.50 cm SL male/unsexed  Found in the Acre River basin (Ref. 97592). Also Ref. 81048. + 
Anostomidae Megaleporinus brinco (Birindelli, Britski & Garavello, 2013) Fr native   18.72 cm SL male/unsexed  Found in the rio de Contas and its tributaries, a medium size coastal river in the states of Minas Gerais and Bahia (Ref. 93224). - 
Anostomidae Megaleporinus conirostris (Steindachner, 1875) Fr native  Boga (Portuguese), Piaba (Portuguese), Piapara (Portuguese)   36.50 cm TL male/unsexed  Known from the Paraíba do Sul River basin (Ref. 36801). Type locality: Rio Parahyba at Mendez, Juiz de Fora and Palmeira; Rio Doco; Rio Mucuri; Parahyba Valley, Brazil (Ref. 26282). + 
Anostomidae Megaleporinus elongatus (Valenciennes, 1850) Fr native  Piapara (Portuguese), Piau (Portuguese), Piau verdadeiro (Portuguese)   50.00 cm TL male/unsexed 19 TL Known only from the Rio Jequitinhonha and Rio Pardo, rivers of the eastern region of Brazil in the states of Minas Gerais and Bahia. Record from São Francisco River seems to be erroneous (Ref. 93038). Also Ref. 36801. + 
Anostomidae Megaleporinus garmani (Borodin, 1929) Fr native    24.70 cm SL male/unsexed  Known from the Jequitinhonha River basin (Ref. 36801). - 
Anostomidae Megaleporinus macrocephalus (Garavello & Britski, 1988) Fr native  Piaussu (Portuguese), Piauçu (Portuguese), Piavuçu (Portuguese)   68.40 cm TL male/unsexed  Known from the Paraguay River basin (Ref. 36801). Museum: Rio Cuiabá, Barao de Melgaço, Mato Grosso, MZUSP 36586 (holotype of L. macrocephalus, 29.5 cm SL) (Ref. 27925). + 
Anostomidae Megaleporinus obtusidens (Valenciennes, 1837) Fr, Fi, Aq native  Piapara (Portuguese), Piaussú (Portuguese), Piaba uçu (Portuguese), Piabuçu (Portuguese), Piau (Portuguese), Piau verdadeiro (Portuguese), Piava (Portuguese), Piava uçu (Portuguese), Piavuçu (Portuguese) scarce (very unlikely) 76.00 cm TL male/unsexed 16.1 TL Known from the Paraná, Uruguay, Paraguay, Rio Guaíba and São Francisco River basins (Ref. 93038). Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076), and Piracicaba river (Ref. 50076). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 27925, 79585, 36801. + 
Anostomidae Megaleporinus piavussu (Britski, Birindelli & Garavello, 2012) Fr native   38.02 cm SL male/unsexed  Known only from the upper Rio Paraná (Ref. 93038). - 
Anostomidae Megaleporinus reinhardti (Lütken, 1875) Fr native  Piau (Portuguese), Piau rajado (Portuguese), Piau três pintas (Portuguese), Piau-cabecudo (Portuguese), Rajadinho (Portuguese), Timboré pintado (Portuguese)   17.00 cm SL male/unsexed  Known from São Francisco River basin (Ref. 36801). - 
Anostomidae Megaleporinus trifasciatus (Steindachner, 1876) Fr, Fi native  Araçu cabeça gorda (Portuguese), Aracu cabeça gorda (Portuguese), Piau (Portuguese), Piau cachoeira (Portuguese), Piau capelobo (Portuguese), Piau coco (Portuguese), Piau curimatá (Portuguese), Piau danta (Portuguese)   29.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36801). Also Ref. 598, 12202. + 
Trichomycteridae Megalocentor echthrus de Pinna & Britski, 1991 Fr native    8.79 cm SL male/unsexed  Known from Rio Madeira and Rio Purus. - 
Doradidae Megalodoras uranoscopus (Eigenmann & Eigenmann, 1888) Fr, Fi native  Bacu (Portuguese), Cuiú cuiú (Portuguese), Cuiú cuiú amarelo (Portuguese), Cuiú cuiú boca curta (Portuguese), Cumbá (Portuguese), Dukeru (Portuguese), Mandí serra (Portuguese), Rebacao (Portuguese), Rebeca (Portuguese)   53.00 cm SL male/unsexed ;60.00 cm SL female  Type locality, Lake Hyanuary, Amazonas. Found in fish markets in Santarém (Ref. 12202). Also Ref. 6868. + 
Pimelodidae Megalonema amaxanthum Lundberg & Dahdul, 2008 Fr native    24.10 cm SL male/unsexed ;31.20 cm SL female  Known from the Amazon River basin (Ref. 79495). - 
Pimelodidae Megalonema platanum (Günther, 1880) Fr, Thr native  Jundiá-branco (Portuguese), Fidalgo (Portuguese)   40.00 cm SL male/unsexed  Known from Paraná River basin (Ref. 36506). Reported from the Uruguay River (Ref. 79585). Regarded as threatened in the state of Minas Gerais (Ref. 26603). + 
Pimelodidae Megalonema platycephalum Eigenmann, 1912 Fr native    30.00 cm TL male/unsexed    + 
Crenuchidae Melanocharacidium auroradiatum Costa & Vicente, 1994 Fr native   4.33 cm SL male/unsexed  Known from the Araguaia River basin (Ref. 37059). Museum: small tributary of Rio Verde, 1 km south of Sao Miguel do Araguaia, Rio Araguaia basin, Goiás, MZUSP 45769 (Ref. 27925). - 
Crenuchidae Melanocharacidium depressum Buckup, 1993 Fr native   3.40 cm TL male/unsexed  Occurs in Uatumã and Negro River basins (Ref. 37059). Specimens collected in rapids over rocky areas. Museum: Cachoreira Morena, Rio Uatuma, Estado do Amazonas, INPA 1738 (holotype, 2.71 cm SL) (Ref. 13683). Also Ref. 27925, 37059. - 
Crenuchidae Melanocharacidium dispilomma Buckup, 1993 Fr native   5.00 cm TL male/unsexed  Known from the Amazon (Ref. 37059) and Machado River basin (Ref. 97589). Museum: Cachoeira, Rio Uatuma, Estado do Amazonas, INPA 6628 (holotype, 4.02 cm SL) (Ref. 13683). Also Ref. 12225, 27925. - 
Crenuchidae Melanocharacidium nigrum Buckup, 1993 Fr native   6.70 cm SL male/unsexed  Recorded from Rio Mucajaí, Rio Uraricoera, and drainages of Branco and Uatumã rivers. Museum: Rio Mucajaí, upstream of Ilha do Paredao, Território Federal de Roraima, INPA 1681 (holotype, 5.38 cm SL) (Ref. 13683). Also Ref. 27925, 37059. - 
Crenuchidae Melanocharacidium pectorale Buckup, 1993 Fr native   4.36 cm TL male/unsexed  Known from the Amazon (Ref. 37059) and Machado River basin (Ref. 97589). Museum: Cachoeira Morena, Rio Uatuma, Estado do Amazonas, INPA 6629 (holotype, 3.15 cm SL) (Ref. 13683). Also Ref. 27925. - 
Rivulidae Melanorivulus aithogrammus Nielsen & Britzke, 2019 Fr native   2.80 cm SL male/unsexed ;1.75 cm SL female  Type locality of Melanorivulus aithogrammus from Itaituba, Igarapé da Aldeia, Rio Tapajós basin, Pará, Brazil, MZUSP 123088 (Ref. 128908). - 
Rivulidae Melanorivulus amambaiensis Volcan, Severo-Neto & Lanés, 2018 Fr native   2.79 cm SL male/unsexed ;2.87 cm SL female  Type locality of Melanorivulus amambaiensis, Mato Grosso do Sul State, near of municipality of Naviraí, first order stream of Rio Amambai, margin of BR 487 highway (Ref. 119399). + 
Rivulidae Melanorivulus apiamici (Costa, 1989) Fr endemic    3.00 cm SL male/unsexed  Known from Paraná River basin (Ref. 36579). + 
Rivulidae Melanorivulus atlanticus Costa, Bragança & Ottoni, 2015 Fr native   1.78 cm SL male/unsexed ;1.49 cm SL female  Found in the coastal plains of northeastern Brazil, between the villages of Lagoa Grande and Pau Seco, Estado de Sergipe (Ref. 101434). - 
Rivulidae Melanorivulus bororo (Costa, 2008) Fr native   2.46 cm SL male/unsexed ;2.19 cm SL female  Known only from the type locality, swampy flooodplains of córrego Buriti mouth, close to Santana River, upper Paraguay River basin in Mato Grosso (Ref. 76975). - 
Rivulidae Melanorivulus crixas (Costa, 2007) Fr native   2.73 cm SL male/unsexed ;2.63 cm SL female  Type locality of Rivulus crixas, Estado de Goiás: stream tributary to rio Crixás Mirim, rio Crixás Açu drainage, rio Araguaia basin, road GO-164, about 5 km S from Nova Crixás/ Known from the Crixás Açu River drainage of the Araguaia River basin (Ref. 59346). - 
Rivulidae Melanorivulus cyanopterus (Costa, 2005) Fr native   2.76 cm SL male/unsexed ;2.42 cm SL female  Known only from the type locality, floodplains of rio Tenente Amaral, upper rio São Lourenço drainage, rio Paraguay basin, central Brazil. - 
Rivulidae Melanorivulus dapazi (Costa, 2005) Fr native   3.17 cm SL male/unsexed ;2.49 cm SL female  Recorded from the upper section of the rio Correntes drainage, rio Paraguay basin, central Brazil. - 
Rivulidae Melanorivulus decoratus (Costa, 1989) Fr endemic   5.00 cm TL male/unsexed  Recorded only from a few localities in the Rio Sao Francisco basin (Ref. 26657). Also Ref. 27139, 36579. - 
Rivulidae Melanorivulus egens (Costa, 2005) Fr native    Type locality, Município de Camapuã, road BR-060, rio São Domingos, upper rio Verde drainage, rio Paraná basin, Estsdo de Mato Grosso do Sul, 532 m elevation (Ref. 54355). - 
Rivulidae Melanorivulus faucireticulatus (Costa, 2008) Fr native   3.03 cm SL male/unsexed ;2.31 cm SL female  Known only from small ponds in Bonfim river floodplains of the upper Claro drainage, upper Paraná river basin in central Brazil (Ref. 75134). - 
Rivulidae Melanorivulus giarettai (Costa, 2008) Fr native   3.23 cm SL male/unsexed ;3.72 cm SL female  Known from three localities located in the middle Araguari river drainage, upper Paraná river basin in Minas Gerais (Ref. 75625). - 
Rivulidae Melanorivulus illuminatus (Costa, 2007) Fr native   2.88 cm SL male/unsexed ;3.32 cm SL female  Found in a shallow swamp adjacent to córrego da Queixada, rio dos Bois drainage, rio Paraná basin (Ref. 78126). - 
Rivulidae Melanorivulus imperatrizensis Nielsen & Pinto, 2015 Fr endemic   3.18 cm SL male/unsexed  Currently known only from the type locality, a small headspring in the urban area of the small village of Bananal, close to the middle rio Tocantins channel, Maranhao, Brazil (Ref. 119335). - 
Rivulidae Melanorivulus interruptus Volcan, Severo-Neto & Lanés, 2018 Fr native   3.23 cm SL male/unsexed ;2.90 cm SL female  Type locality of Melanorivulus interruptus, Mato Grosso do Sul State, municipality of Campo Grande, first order stream, in the headwaters of Rio Pardo (Ref. 119399). + 
Rivulidae Melanorivulus ivinhemensis Volcan, Severo-Neto & Lanés, 2018 Fr native   3.01 cm SL male/unsexed ;3.04 cm SL female  Type locality of Melanorivulus ivinhemensis, Brazil, Mato Grosso do Sul State, municipality of Nova Andradina, first order stream of Rio Ivinhema (Ref. 119399). + 
Rivulidae Melanorivulus jalapensis (Costa, 2010) Fr native    Found in Sono River drainage, Tocantins River basin in central Brazil (Ref. 85564). - 
Rivulidae Melanorivulus javahe (Costa, 2007) Fr native   2.40 cm SL male/unsexed ;2.30 cm SL female  Type locality of Rivulus javahe, Estado de Goiás: stream tributary to rio Verde, rio Araguaia basin, serra dos Javaés, road GO-164, about 30 km N from São Miguel do Araguaia, Known from Verde River and Crixás Açu River drainages of the Araguaia River basin (Ref. 59346). - 
Rivulidae Melanorivulus karaja (Costa, 2007) Fr native   3.01 cm SL male/unsexed ;2.81 cm SL female  Type locality of Rivulus karaja, Estado do Tocantins: Município de Dueré: stream tributary to rio Dueré, near road BR-153, 10 km S of rio Dueré, rio Formoso drainage, rio Araguaia basin. Known from the Formoso River drainage of the Araguaia River basin (Ref. 59346). - 
Rivulidae Melanorivulus kayabi (Costa, 2008) Fr native   2.99 cm SL male/unsexed ;2.89 cm SL female  Occurs in the middle and upper reaches of the Tapajós river basin, in altitudes between 261 and 488 m, in central Brazil (Ref. 76937). - 
Rivulidae Melanorivulus kayapo (Costa, 2006) Fr native    Known from the rio Caiapó drainage of the upper rio Araguaia basin (Ref. 57725). - 
Rivulidae Melanorivulus kunzei Costa, 2012 Fr native   3.30 cm SL male/unsexed ;3.22 cm SL female   - 
Rivulidae Melanorivulus leali Costa, 2013 Fr native   3.20 cm SL male/unsexed  Known from a small stream of the Grande river drainage, upper Paraná river basin in south-eastern Brazil (Ref. 94719). - 
Rivulidae Melanorivulus linearis Costa, 2018 Fr native   3.01 cm SL male/unsexed ;2.37 cm SL female  Known only from the upper section of the Rio Pardo, middle Rio Paraná Basin in central Brazil (Ref. 116860). - 
Rivulidae Melanorivulus litteratus (Costa, 2005) Fr native   2.81 cm SL male/unsexed ;3.02 cm SL female   + 
Rivulidae Melanorivulus megaroni (Costa, 2010) Fr native    Known from the Xingu River drainage of the southern Amazon River basin in central Brazil (Ref. 83423). - 
Rivulidae Melanorivulus modestus (Costa, 1991) Fr endemic   4.00 cm TL male/unsexed  Known from the Tapajós River basin (Ref. 36579). Recorded from Rio Mutum, Rio Tapajos basin, Comodoro, Mato Grosso (Ref. 26657). + 
Rivulidae Melanorivulus nigromarginatus Costa, 2018 Fr native   3.56 cm SL male/unsexed ;3.08 cm SL female  Found only in two close small streams in the middle section of the Corrente River drainage, upper Paraná River Basin (Ref. 116860). - 
Rivulidae Melanorivulus nigropunctatus Volcan, Klotzel & Lanés, 2017 Fr native   2.41 cm SL male/unsexed  Known only from a wetland associated with a small stream which is a direct tributary of the main channel of the Rio Verde, upper Rio Paraná basin in Mato Grosso do Sul (Ref. 117357). - 
Rivulidae Melanorivulus ofaie Volcan, Klotzel & Lanés, 2017 Fr native   3.05 cm SL male/unsexed ;2.15 cm SL female  Found only in the wetlands along a c. 50 km stretch on the right bank of the Rio Verde in Ribas do Rio Pardo municipality, Mato Grosso do Sul State (Ref. 117357). - 
Rivulidae Melanorivulus paracatuensis (Costa, 2003) Fr native    Type locality, Stream in Rio Paracatú floodplains near Brasilândia de Minas, road MG 181, Rio São Francisco basin,, ca. 17°00'00"S, 46°00'00"W, Estado de Minas Gerais (Ref. 50838). - 
Rivulidae Melanorivulus paresi (Costa, 2008) Fr native   2.58 cm male/unsexed ;2.30 cm SL female  Found only in a single locality, swampy floodplains of stream tributary to Sepotuba River, an upper tributary of the Paraguay River basin at the Parecis Hills (Chapada dos Parecis) in central Brazil (Ref. 76975). - 
Rivulidae Melanorivulus parnaibensis (Costa, 2003) Fr native    Type locality, Lagoon close to the road BR-135, 18 km northeast of São Dimas, ca. 9°40'S, 45°00'W, Parnaiba R. basin, Piauí, ne. Brazil (Ref. 54621). - 
Rivulidae Melanorivulus pictus (Costa, 1989) Fr endemic   5.00 cm TL male/unsexed  Recorded from streams of the upper and middle sections of the rio Parana basin (Ref. 26657). Also Ref. 27139. + 
Rivulidae Melanorivulus pindorama Costa, 2012 Fr native    Type locality, upper Tocantins. - 
Rivulidae Melanorivulus pinima (Costa, 1989) Fr endemic   3.00 cm SL male/unsexed  Known only from the upper rio Paraná basin in central Brazilian plateau (Ref. 54355). + 
Rivulidae Melanorivulus planaltinus (Costa & Brasil, 2008) Fr native   3.11 cm SL male/unsexed ;2.76 cm SL female  Known only from the type locality in the Cocal River floodplains, Maranhão River drainage, upper Tocantins River basin at an altitude of 1,100 m in central Brazil (Ref. 75171). - 
Rivulidae Melanorivulus proximus Costa, 2018 Fr native   3.00 cm SL male/unsexed ;2.74 cm SL female  Known from the middle section of the Rio Aporé drainage, upper Rio Paraná Basin in central Brazil (Ref. 116860). - 
Rivulidae Melanorivulus punctatus (Boulenger, 1895) Fr native    3.50 cm TL male/unsexed  Recorded from the Paraguay basin (Ref. 26657). + 
Rivulidae Melanorivulus rossoi (Costa, 2005) Fr native   3.57 cm TL male/unsexed  Type locality, stream at road BR-060, 21.5 km southwest from Campo Grande, Inhanduí drainage, rio Paraná basin, ca. 20°40'S, 54°40'W, Estado de Mato Grosso do Sul, Brazil, ca. 500 m elevation. - 
Rivulidae Melanorivulus rubromarginatus (Costa, 2007) Fr native   2.81 cm SL male/unsexed ;2.52 cm SL female  Type locality of Rivulus rubromarginatus, Estado de Goiás: stream tributary to rio Espingarda, rio do Peixe drainage, rio Araguaia basin, road GO-164. Known from the Peixe River drainage of the middle Araguaia River basin (Ref. 59346). - 
Rivulidae Melanorivulus rubroreticulatus Costa, Amorim & Bragança, 2014 Fr native   2.57 cm SL male/unsexed  Known from the floodplains of the lower Xingu river around the town of Altamira, Amazonas river basin in northern Brazil (Ref. 96663). - 
Rivulidae Melanorivulus rutilicaudus (Costa, 2005) Fr native     + 
Rivulidae Melanorivulus salmonicaudus (Costa, 2007) Fr native   2.52 cm SL male/unsexed ;2.47 cm SL female  Type locality of Rivulus salmonicaudus, Estado de Goiás: Montes Claros de Goiás: córrego Dom Bill, a tributary to rio Araguaia, road BR070, about 44 km W of Aparecida do Rio Claro (Ref. 59346). - 
Rivulidae Melanorivulus scalaris (Costa, 2005) Fr native    Rio Sucurúi, rio Aporé and upper rio Correntes drainages, rio Paraná basin, and upper rio Taquari drainage, rio Paragay basin, central Brazil. + 
Rivulidae Melanorivulus schuncki (Costa & De Luca, 2011) Fr native   2.44 cm SL male/unsexed  Known from the Anauerapucu River drainage, lower Amazonas River basin in northern Brazil (Ref. 86535). - 
Rivulidae Melanorivulus ubirajarai Costa, 2012 Fr native   2.99 cm SL male/unsexed ;2.72 cm SL female   - 
Rivulidae Melanorivulus violaceus (Costa, 1991) Fr endemic   5.00 cm TL male/unsexed  Known from the Araguaia River basin (Ref. 36579). + 
Rivulidae Melanorivulus vittatus (Costa, 1989) Fr endemic    Found only in the upper rio Paraná basin in central Brazilian plateau (Ref. 54355). + 
Rivulidae Melanorivulus wallacei Costa, 2016 Fr native   2.83 cm SL male/unsexed ;2.94 cm SL female  Type locality of Melanorivulus wallacei from a stream tributary of the Rio Joao Aires, road TO-010, Rio Tocantins drainage, Município de Palmeirante, Tocantins, Brazil, UFRJ 6871. - 
Rivulidae Melanorivulus zygonectes (Myers, 1927) Fr endemic   4.00 cm TL male/unsexed  Known from the Araguaia, Tocantins, Xingu, and Tapajós River basins (Ref. 36579). Also Ref. 26657, 27139. - 
Cichlidae Mesonauta acora (Castelnau, 1855) Fr endemic    7.10 cm SL male/unsexed  Kown from the Amazon River basin in the Tocantins and Xingu River basins (Ref. 36377). + 
Cichlidae Mesonauta festivus (Heckel, 1840) Fr native  Acará Bandeira (Portuguese), Acará (Portuguese), Acará festivo (Portuguese), Cará (Portuguese)   12.10 cm SL male/unsexed  Known from the Paraná River basin in the Paraguay River drainage, Amazon River basin in the Guaporé, and Jamari and Tapajós River drainages (Ref. 36377). + 
Cichlidae Mesonauta guyanae Schindler, 1998 Fr native   11.20 cm TL male/unsexed  Known from the Amazon River basin in the Negro River drainage (Ref. 36377). + 
Cichlidae Mesonauta insignis (Heckel, 1840) Fr native    12.40 cm SL male/unsexed  Known from the Negro River drainage of the Amazon River basin (Ref. 36377). + 
Serrasalmidae Metynnis argenteus Ahl, 1923 Fr, Fi endemic  Pacu (Portuguese), Pacu-marreca (Portuguese)   13.96 cm SL male/unsexed  Known from Tapajós River basin (Ref. 39031). Type locality is Rio Tapajos. Found regularly in markets in Santarém (Ref. 12202) but restricted to area south of lower Amazon according to Ref. 34077. + 
Serrasalmidae Metynnis cuiaba Pavanelli, Ota & Petry, 2009 Fr native   14.25 cm SL male/unsexed  Known from the upper portions of rio Paraguai basin, in Cuiabá and Manso river drainages, including lakes (baías) in the Pantanal, Mato Grosso State, Central Brazil (Ref. 81196). - 
Serrasalmidae Metynnis fasciatus Ahl, 1931 Fr endemic  Pacu-marreca (Portuguese), Pacu (Portuguese)  5.80 cm SL male/unsexed  Known from Capiuru River basin in middle Amazon River drainage (Ref. 39031). + 
Serrasalmidae Metynnis guaporensis Eigenmann, 1915 Fr native  Pacu (Portuguese), Pacu-marreca (Portuguese)   16.00 cm SL male/unsexed  Known from the Guaporé River basin (Ref. 39031). Type locality: Rio Guaporé at Maciél, Brazil (Ref. 34077). - 
Serrasalmidae Metynnis hypsauchen (Müller & Troschel, 1844) Fr, Fi native  Pacu (Portuguese), Pacu dente seco (Portuguese), Pacu lombo de foia (Portuguese), Pacu-marreca (Portuguese)   18.00 cm SL male/unsexed  Also Ref. 4537, 39031. + 
Serrasalmidae Metynnis lippincottianus (Cope, 1870) Fr native  Pacu (Portuguese), Pacu-marreca (Portuguese) common (usually seen) 16.40 cm SL male/unsexed  Amazon, common in white water. Reports from the Rio Suia Missu (Mato Grosso) are misidentifications of M. argenteus (Ref. 34077). Also Ref. 598, 39031. + 
Serrasalmidae Metynnis luna Cope, 1878 Fr native    12.90 cm SL male/unsexed   + 
Serrasalmidae Metynnis maculatus (Kner, 1858) Fr, Fi native  Pacu peva (Portuguese), Pacu (Portuguese), Pacu-peva (Portuguese), Piranha (Portuguese)   18.00 cm TL male/unsexed  Lower Oyapock, border to French Guiana (Ref. 35237). + 
Serrasalmidae Metynnis mola Eigenmann & Kennedy, 1903 Fr native  Pacu peva (Portuguese), Pacu-peva (Portuguese)   15.00 cm TL male/unsexed    + 
Serrasalmidae Metynnis polystictus Zarske & Géry, 2008 Fr native   16.70 cm SL male/unsexed   - 
Trichomycteridae Microcambeva barbata Costa & Bockmann, 1994 Fr native  Cambeva (Portuguese)   2.60 cm SL male/unsexed  Found in coastal drainages in Rio de Janeiro and Espírito Santo (Ref. 39970). - 
Trichomycteridae Microcambeva draco Mattos & Lima, 2010 Fr native    Known from Rio Jucuruçu basin in Bahia State, northeastern Brazil (Ref. 85561). - 
Trichomycteridae Microcambeva ribeirae Costa, Lima & Bizerril, 2004 Fr native   4.81 cm SL male/unsexed  Known from Rio Ribeira do Iguape basin in southeastern Brazil (Ref. 53272). - 
Crenuchidae Microcharacidium eleotrioides (Géry, 1960) Fr native    2.10 cm SL male/unsexed   + 
Crenuchidae Microcharacidium gnomus Buckup, 1993 Fr native   2.20 cm SL male/unsexed  Recorded from the Rio Negro drainage, Amazon basin (Ref. 13683). Also Ref. 37059. - 
Crenuchidae Microcharacidium weitzmani Buckup, 1993 Fr native    1.20 cm SL male/unsexed  Recorded from the Amazon and Negro rivers (Ref. 13683). Also Ref. 37059. - 
Pseudopimelodidae Microglanis ater Ahl, 1936 Fr endemic   8.10 cm SL male/unsexed   - 
Pseudopimelodidae Microglanis cibelae Malabarba & Mahler, 1998 Fr endemic    7.10 cm SL male/unsexed  Found in rivers from the coastal slope of Serra Geral Formation, in coastal drainages from northern Rio Grande do Sul and Santa Catarina states (Ref. 33009). Also Ref. 39418. + 
Pseudopimelodidae Microglanis cottoides (Boulenger, 1891) Fr endemic  Bagrinho (Portuguese)   6.75 cm SL male/unsexed  Known from Laguna dos Patos and rio Uruguay drainages (Ref. 39418). Also Ref. 81048. + 
Pseudopimelodidae Microglanis eurystoma Malabarba & Mahler, 1998 Fr endemic  Bagrinho (Portuguese)  7.76 cm SL male/unsexed  Known only from the upper rio Uruguay drainage in Rio Grande do Sul and Santa Catarina states, southern Brazil (Ref. 33009). Also Ref. 39418. - 
Pseudopimelodidae Microglanis garavelloi Shibatta & Benine, 2005 Fr native    4.18 cm SL male/unsexed  Found in the tributaries of rio Paranapanema and rio Tietê of the upper rio Paraná basin (Ref. 56901). + 
Pseudopimelodidae Microglanis leptostriatus Mori & Shibatta, 2006 Fr native   4.23 cm SL male/unsexed  Known from the tributaries of the middle-upper course of São Francisco River basin (Ref. 58766). - 
Pseudopimelodidae Microglanis lundbergi Jarduli & Shibatta, 2013 Fr native   2.77 cm SL male/unsexed  Found in rio Amazonas, near the Madeira and Itacoatiara tributaries, and from rio Solimões, in Tefé, Amazonas (Ref. 94156). - 
Pseudopimelodidae Microglanis maculatus Shibatta, 2014 Fr native   3.65 cm SL male/unsexed  Found in the rio dos Patos basin, upper rio Tocantins basin in Barro Alto, Goiás State (Ref. 95500). - 
Pseudopimelodidae Microglanis malabarbai Bertaco & Cardoso, 2005 Fr native   5.01 cm SL male/unsexed   - 
Pseudopimelodidae Microglanis minutus Ottoni, Mattos & Barbosa, 2010 Fr native    2.97 cm SL male/unsexed  Known from Rio Barra Seca basin in Espírito Santo state, southeastern Brazil (Ref. 86273). - 
Pseudopimelodidae Microglanis nigripinnis Bizerril & Perez-Neto, 1992 Fr endemic   4.72 cm SL male/unsexed  Known from Macacu River basin in Rio de Janeiro (Ref. 39418). - 
Pseudopimelodidae Microglanis oliveirai Ruiz & Shibatta, 2011 Fr native   2.63 cm SL male/unsexed   - 
Pseudopimelodidae Microglanis parahybae (Steindachner, 1880) Fr native    8.00 cm SL male/unsexed  Known from Paraíba do Sul river basin (Ref. 39418). Also Ref. 6868. - 
Pseudopimelodidae Microglanis pataxo Sarmento-Soares, Martins-Pinheiro, Aranda & Chamon, 2006 Fr native    3.90 cm SL male/unsexed  Known from coastal drainages of rio Peruípe, rio Jucuruçu and rio Cahy in southeastern Bahia (Ref. 57827). - 
Pseudopimelodidae Microglanis pleriqueater Mattos, Ottoni & Barbosa, 2013 Fr native   5.18 cm SL male/unsexed  Type locality of Microglanis pleriqueater from Águas Claras river, tributary of São João river, 29 km northwest from Silva Jardim municipality, Rio de Janeiro, Brazil, UFRJ 8183 (Ref. 94539). - 
Pseudopimelodidae Microglanis poecilus Eigenmann, 1912 Fr native    6.90 cm SL male/unsexed  Recorded from Machado river basin (Ref. 97589). + 
Pseudopimelodidae Microglanis reikoae Ruiz, 2016 Fr native   2.86 cm SL male/unsexed  Type locality of Microglanis reikoae, Bahia, São Desidério, rio dos Angicos. Known from streams in the middle rio São Francisco basin (Ref. 130492). - 
Pseudopimelodidae Microglanis robustus Ruiz & Shibatta, 2010 Fr native   2.33 cm SL male/unsexed  Found in two localities in Rio Tocantins: in rapids of Jatobal and in small rapids below Jatobal, in Tucuruí, Pará. Collected in 1982 in rapids upstream and downstream of the district of Jatobal (Tucuruí, State of Pará), that were flooded by the construction of Tucuruí dam in 1984. This represents the first Microglanis species encountered in rapids as all other species occur among marginal submerged vegetation, depositional substrata of leaves, and/or trunks in calm water stretches of rivers. The disappearance of those environments may be the reason that no other specimen was captured after the flood along 28 years. Maybe threatened by extinction due to its restricted distribution in the rapids of Rio Tocantins, a biotope currently destroyed by hydroelectric power plants (Ref. 85327). - 
Pseudopimelodidae Microglanis sparsus Ruiz, 2016 Fr native   2.31 cm SL male/unsexed  Type locality of Microglanis sparsus, Mato Grosso: Campinápolis: rio Couto de Magalhães (upper rio Xingu basin), near Vila São José do Rio do Couto (Ref. 130492). - 
Pseudopimelodidae Microglanis xerente Ruiz, 2016 Fr native   2.71 cm SL male/unsexed  Type locality of Microglanis xerente, Tocantins, Aurora do Tocantins, córrego Cana Brava. Known from small tributaries from the upper-middle rio Tocantins basin, Tocantins state (Ref. 130492). - 
Pseudopimelodidae Microglanis xylographicus Ruiz & Shibatta, 2011 Fr native   2.78 cm SL male/unsexed   - 
Loricariidae Microlepidogaster arachas Martins, Calegari & Langeani, 2013 Fr native   4.34 cm SL male/unsexed  Found in the tributaries to rio Araguari, rio Perdizes, and rio Dourados, all pertaining to the rio Paranaíba drainage, upper rio Paraná basin (Ref. 92936). - 
Loricariidae Microlepidogaster bourguyi Miranda Ribeiro, 1911 Fr native     Type locality. - 
Loricariidae Microlepidogaster dimorpha Martins & Langeani, 2011 Fr native   3.77 cm SL male/unsexed  Known from rio Uberaba and riacho Grotão, both tributaries of the rio Grande, upper rio Paraná system in Minas Gerais (Ref. 86675). - 
Loricariidae Microlepidogaster discontenta Calgari, Silva & Reis, 2014 Fr native   4.02 cm SL male/unsexed  Found in córrego Arrependido and one tributary creek, in the upper reaches of the rio São Francisco basin, along the border between Minas Gerais and Goiás States, in central Brazil (Ref. 98822). - 
Loricariidae Microlepidogaster discus Martins, Rosa & Langeani, 2014 Fr native   4.64 cm SL male/unsexed  Known from the headwaters of the rio Itacambiruçu, an affluent on the left side of the rio Jequitinhonha, a coastal basin in southeastern Brazil (Ref. 97523). - 
Loricariidae Microlepidogaster longicolla Calegari & Reis, 2010 Fr native   4.64 cm SL male/unsexed  known from five localities in the upper reaches of the rio São Bartolomeu, a tributary to the rio Corumbá, itself a tributary to the rio Paranaíba of the upper rio Paraná basin near Brasília in central Brazil (Ref. 85171). + 
Loricariidae Microlepidogaster negomata Martins, Cherobim, Andrade & Langeani, 2017 Fr native   4.11 cm SL male/unsexed  Type locality of Microlepidogaster negomata: Rio São Francisco basin, Minas Gerais (Ref. 115560). - 
Loricariidae Microlepidogaster perforata Eigenmann & Eigenmann, 1889 Fr native   5.00 cm SL male/unsexed  Known from the Carandaí River in upper Paraná River basin (Ref. 36885). Type locality: Rio Carandahí, trib. of Rio das Velhas at Carandaí, Minas Gerais, Brazil (Ref. 26282). - 
Hemiodontidae Micromischodus sugillatus Roberts, 1971 Fr native   17.00 cm SL male/unsexed  Known from the Amazon, Madeira, Negro and Solimões River basins (Ref. 38289). Museum: Tarumazinho, Igarapé, northwest of Manaus, left bank of Rio Negro, Amazonas, MZUSP 6773 (holotype of M sugillatus, 15.2 cm SL) (Ref. 27925). Also Ref. 598. - 
Aspredinidae Micromyzon akamai Friel & Lundberg, 1996 Fr native    1.58 cm SL male/unsexed  Known from two localities of the Amazon; approximately 115 km below the mouth of Rio Tapajos near the town of Monte Alegre and lower Rio Tocantins and about 30 km above confluence with Rio Pará (Ref. 13087). Also Ref. 36695. + 
Eleotridae Microphilypnus acangaquara Caires & Figueiredo, 2011 Fr native   1.41 cm SL male/unsexed   - 
Eleotridae Microphilypnus amazonicus Myers, 1927 Fr native   2.40 cm SL male/unsexed  Known from the lower Negro River basin (Ref. 50190). - 
Eleotridae Microphilypnus macrostoma Myers, 1927 Fr native   2.00 cm SL male/unsexed  Known from the lower Negro River basin (Ref. 50190). - 
Eleotridae Microphilypnus ternetzi Myers, 1927 Fr native    2.00 cm SL male/unsexed   - 
Syngnathidae Microphis brachyurus (Bleeker, 1854) Fr native    22.00 cm SL male/unsexed    + 
Loricariidae Microplecostomus forestii Silva, Roxo, Ochoa & Oliveira, 2016 Fr native   3.83 cm SL male/unsexed  Occurs in Roncador Stream and the das Brancas Stream, both tributaries of the Tocantizinho River in the Tocantins basin (Ref. 115935). - 
Poeciliidae Micropoecilia bifurca (Eigenmann, 1909) Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  3.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 50894). - 
Poeciliidae Micropoecilia branneri (Eigenmann, 1894) Fr native  Barrigudinho (Portuguese), Cospe cospe (Portuguese), Guaru (Portuguese), Guaru guaru (Portuguese)  3.00 cm TL male/unsexed ;4.00 cm TL female  Known from the Amazon River basin (Ref. 50894). Type locality, Santarém, Pará (Ref. 50838). Also Ref. 26855. - 
Poeciliidae Micropoecilia minima (Costa & Sarraf, 1997) Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  1.60 cm SL male/unsexed ;2.36 cm SL female  Found in Rio Guamá basin in Ourém, Para (Ref. 26655). Also Ref. 50894. + 
Centrarchidae Micropterus salmoides (Lacepède, 1802) Fr not established  Black bass (Portuguese), Boca grande (Portuguese)   97.00 cm TL male/unsexed    + 
Characidae Microschemobrycon callops Böhlke, 1953 Fr native    3.48 cm SL male/unsexed  Found in Negro and Paru do Oeste River basins (Ref. 38376). Type locality: Camanaos Rapids, Rio Negro, about 0°10'N, 66°55'W (Ref. 26282). - 
Characidae Microschemobrycon casiquiare Böhlke, 1953 Fr native    3.48 cm SL male/unsexed  Found in the Negro and Madeira River basins (Ref. 38376). - 
Characidae Microschemobrycon elongatus Géry, 1973 Fr native   4.50 cm TL male/unsexed  Type locality: Rio Suiazinho, Rio Xingù basin, 12°49'S, 51°46'W (Ref. 26282). + 
Characidae Microschemobrycon geisleri Géry, 1973 Fr native    2.80 cm SL male/unsexed  Type locality: Igarapé, about 35 km northwest from Obidos, Rio Curuçamba drainage, lower Amazon basin (Ref. 26282). - 
Characidae Microschemobrycon guaporensis Eigenmann, 1915 Fr native    3.23 cm SL male/unsexed  Found in Machado river basin (Ref. 97589). Type locality: Rio Guaporé at Maciél, Amazon system (Ref. 26282). - 
Characidae Microschemobrycon melanotus (Eigenmann, 1912) Fr native    4.30 cm TL male/unsexed  Found in the Negro River basin (Ref. 38376). - 
Characidae Microschemobrycon meyburgi Meinken, 1975 Fr native   2.20 cm SL male/unsexed  Found in the Branco River basin (Ref. 38376). Museum: Rio Xeriuini, MZUSP 48131 (Ref. 27925). - 
Hypopomidae Microsternarchus bilineatus Fernández-Yépez, 1968 Fr native    12.00 cm TL male/unsexed  Found in the Negro River basin (Ref. 37053). - 
Hypopomidae Microsternarchus brevis Cox Fernandes, Nogueira, Williston & Alves-Gomes, 2015 Fr native   5.30 cm TL male/unsexed ;5.32 cm TL female  Type locality of Microsternarchus brevis. It also occurs in black-water streams along the middle part of the rio Negro Basin (Amazon). It was never captured upriver of the town of São Gabirel da Cachoeira nor below the confluence of the Branco and Negro rivers (Ref. 104297). + 
Cichlidae Mikrogeophagus altispinosus (Haseman, 1911) Fr native    5.60 cm SL male/unsexed  Known from the Amazon River basin in the Guaporé River drainage (Ref. 36377). + 
Characidae Mimagoniates barberi Regan, 1907 Fr questionable   3.45 cm SL male/unsexed  Reported from Pantanal (Ref. 81048). Outside the distributional range, occurrence needs further confirmation. - 
Characidae Mimagoniates inequalis (Eigenmann, 1911) Fr native  Lumbari (Portuguese), Lambari (Portuguese)  3.26 cm SL male/unsexed  Found in blackwater tributaries of lower Jacuí River and blackwater coastal streams and swamps of Rio Grande do Sul (Ref. 38597). Also Ref. 4537. + 
Characidae Mimagoniates lateralis (Nichols, 1913) Fr native    3.30 cm SL male/unsexed  Found in coastal blackwater streams in Paraná and São Paulo (Ref. 38597). Status in 1996 is vulnerable according to Ref. 30296. - 
Characidae Mimagoniates microlepis (Steindachner, 1877) Fr native  Lambari azul (Portuguese), Piabinha azul (Portuguese)   6.11 cm SL male/unsexed 3.25 TL Occurs usually in clear coastal streams from southern Bahia to northern Rio Grande do Sul (Ref. 38597). Type locality: Brooks near Rio de Janeiro, Rio dos Macacos, Brazil (Ref. 26282). + 
Characidae Mimagoniates pulcher Menezes & Weitzman, 2009 Fr native   3.70 cm SL male/unsexed  Known from an uncertain locality in the upper rio Paraguai in Mato Grosso (Ref. 82395). - 
Characidae Mimagoniates rheocharis Menezes & Weitzman, 1990 Fr native  Lambari-azul (Portuguese)   4.78 cm SL male/unsexed  Found in coastal streams from southeastern Santa Catarina to northeastern Rio Grande do Su (Ref. 38597). Museum: near Praia Grande, Rio Faxinalzinho at Mae dos Homens, Santa Catarina, MZUSP 40278 (holotype of M. rheocharis, 4.73 cm SL) (Ref. 27925). + 
Characidae Mimagoniates sylvicola Menezes & Weitzman, 1990 Fr native    3.02 cm SL male/unsexed  Found in coastal blackwater streams in southeastern Bahia (Ref. 38597). Museum: forest stream tributary to Atlantic, near Fazenda Embaçuaba, Município de Prado, Bahia, MZUSP 36612 (holotype of M. sylvicola, 3.02 cm SL) (Ref. 27925). - 
Trichomycteridae Miuroglanis platycephalus Eigenmann & Eigenmann, 1889 Fr native    1.23 cm NG male/unsexed  Known from Solimões (Ref. 39970) and Machado River basins (Ref. 97589). Type locality: Rio Jutahy, trib. Of Rio Solimoes, Amazonas, Brazil (Ref. 26282, 6868). + 
Rivulidae Moema apurinan Costa, 2004 Fr native    Known from the upper Rio Purus drainage, Amazon basin, northern Brazil (Ref. 52556). - 
Rivulidae Moema heterostigma Costa, 2003 Fr native   7.35 cm SL male/unsexed  Known from Rio Cuiabá floodplains, Rio Paraguay basin in Mato Grosso (Ref. 52822). - 
Rivulidae Moema nudifrontata Costa, 2003 Fr native    Known from Estado de Roraima (Ref. 50838). + 
Rivulidae Moema pepotei Costa, 1993 Fr native   12.00 cm TL male/unsexed  Known from the Amazon River (Ref. 36579). + 
Rivulidae Moema piriana Costa, 1989 Fr endemic   12.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36579). + 
Rivulidae Moema portugali Costa, 1989 Fr endemic   12.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36579). - 
Rivulidae Moema staecki (Seegers, 1987) Fr native   12.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36579). + 
Characidae Moenkhausia affinis Steindachner, 1915 Fr native  Lambari (Portuguese)  6.00 cm SL male/unsexed  Found in the lower Negro River basin (Ref. 38376). - 
Characidae Moenkhausia agnesae Géry, 1965 Fr native  Lambari (Portuguese)  6.90 cm SL male/unsexed  Recorded from I'arapé Préto, along Upper Amazon, near Belem, about 60 km below Leticia, Brazil (Ref. 26282). Also Ref. 598. + 
Characidae Moenkhausia andrica Reia, Oliveira & Benine, 2021 Fr native   7.02 cm SL male/unsexed  Type locality of Moenkhausia andrica, Mato Grosso, Diamantino, ribeirao Santo Antônio, rio Arinos, rio Tapajos basin. Known from the rio Juruena and its tributaries: rio Arinos, rio do Sangue and rio Papagaio (Ref. 124591). Status of threat: It is known from diverse localities in the rio Juruena basin and found in areas already impacted by agricultural activities and hydroelectric reservoirs. Thus, this species should be categorized as least concern (LC) following the categories and criteria of the IUCN (2019) (Ref. 124591). - 
Characidae Moenkhausia aurantia Bertaco, Jerep & Carvalho, 2011 Fr native   4.95 cm SL male/unsexed 3.57 SL Found in the tributaries of the rio Paranã, upper rio Tocantins basin in the Chapada dos Veadeiros region, Brazilian Cerrado, Goiás (Ref. 87319). - 
Characidae Moenkhausia barbouri Eigenmann, 1908 Fr native  Lambari (Portuguese)  6.50 cm TL male/unsexed  Known from the Amazon River basin (Ref. 38376). Recorded from Villa Bella, Amazonas (Ref. 26282). - 
Characidae Moenkhausia bonita Benine, Castro & Sabino, 2004 Fr native    8.53 cm SL male/unsexed  Rio Baía Bonita, 21°09'S, 56°25'W, Parque Baía Bonita, "Aguáio Natural", upper Rio Miranda, Rio Parguay basin, Mato Grosso do Sul, sw. Brazil. + 
Characidae Moenkhausia britskii Azevedo-Santos & Benine, 2016 Fr native   5.83 cm SL male/unsexed  Type locality of Moenkhausia britskii, Igarapé da Cachoeira, Içá River, Amazon basin, Santo Antônio do Içá, Amazonas (Ref. 112434). - 
Characidae Moenkhausia browni Eigenmann, 1909 Fr native   8.20 cm TL male/unsexed  Recorded from igarapé Apeu, Boa Vista, Castanhal, Pará , MZUSP 17140 (Ref. 46237). + 
Characidae Moenkhausia celibela Marinho & Langeani, 2010 Fr native   4.90 cm TL male/unsexed  Type locality, Igarapé tributary of the Rio Tapajós, at the bridge of the road between Pimental and Itaituba, 2 km from Pimental, Pará State, MZUSP 102984 (holotype of Moenkhausia celibela, 3.19 cm SL). Known from Rio Amazonas at Santarém, Rio Maraú, several localities in the Rio Tapajós, Rio Curuá-Una, Rio Xingu and Rio Jari, all from the Amazon basin (Ref. 85060). - 
Characidae Moenkhausia ceros Eigenmann, 1908 Fr native  Lambari (Portuguese)   5.00 cm TL male/unsexed  Recorded from Rio Tapajós, Pederneiras, poço de Pedral, Pará, MZUSP 30275 (Ref. 46237). Found in the Amazon River (Ref. 38376). + 
Characidae Moenkhausia chlorophthalma Sousa, Netto-Ferreira & Birindelli, 2010 Fr native   6.79 cm SL male/unsexed  Known from the type locality: Pará, Altamira, rio Treze de Maio, tributary of rio Curuá, rio Iriri basin, rio Xingu drainage, MZUSP 99412 (holotype of Moenkhausia chlorophthalma, 6.74 cm SL) (Ref. 84462). - 
Characidae Moenkhausia chrysargyrea (Günther, 1864) Fr native  Lambari (Portuguese)   12.00 cm SL male/unsexed  Occurs in the Amazon River (Ref. 12225). + 
Characidae Moenkhausia collettii (Steindachner, 1882) Fr native  Lambari (Portuguese) common (usually seen) 6.40 cm TL male/unsexed  Found in Amazon and Machado river basin (Ref. 97589). + 
Characidae Moenkhausia comma Eigenmann, 1908 Fr native  Lambari (Portuguese)   7.40 cm SL male/unsexed  Found in the Amazon River basin (Ref. 38376). Recorded from Lago Cudajas, Amazonas (Ref. 598). + 
Characidae Moenkhausia copei (Steindachner, 1882) Fr native   6.00 cm SL male/unsexed  Found in the Amazon River basin (Ref. 38376). Recorded from Rio Uraricoera, Roraima, MZUSP 30263 (Ref. 46237). Type locality, Santarém, Amazon R., Pará (Ref. 46206). + 
Characidae Moenkhausia cosmops Lima, Britski & Machado, 2007 Fr native   5.37 cm SL male/unsexed  Type locality of Moenkhausia cosmops, Mato Grosso, Sapezal, córrego Vinte e Cinco de Maio, near its mouth at the Rio Papagaio. Found in the tributaries of the upper rio Sepotuba in the rio Paraguai basin and tributaries of the rio Juruena in the rio Tapajôs basin in Mato Grosso, central Brazil (Ref. 72399). + 
Characidae Moenkhausia costae (Steindachner, 1907) Fr native  Lambari (Portuguese), Piaba (Portuguese)   5.90 cm SL male/unsexed  Recorded from Sao Francisco and Itapicuru rivers (Ref. 598); Rio Carnaíba, Bom Jesus da Lapa, Bahia, MZUSP 54705 (Ref. 46237). + 
Characidae Moenkhausia cotinho Eigenmann, 1908 Fr native  Lambari (Portuguese), Pira miri (Portuguese)   6.12 cm SL male/unsexed  Type locality, Rio Parahyba do Norte at Joao Pessoa and Pará (Ref. 46206). Recorded from Rio Negro, above Barcelos, Barcelos, Amazonas, MZUSP 29829 (Ref. 46237). + 
Characidae Moenkhausia dasalmas Bertaco, Jerep & Carvalho, 2011 Fr native   4.29 cm SL male/unsexed  Type locality, Goiás, Cavalcante, tributary of the rio das Almas about 8 km North of Cavalcante on GO 241 road, upper rio Tocantins basin, between Cavalcante and Minaçu, UFRGS 11221 (holotype of Moenkhausia dasalmas, 4.29 cm SL). Known from tributaries of the rio das Almas, rio Paranã drainage, upper rio Tocantins basin, in the Chapada dos Veadeiros region, Brazilian Cerrado, Goiás (Ref. 86678). - 
Characidae Moenkhausia diamantina Benine, Castro & Santos, 2007 Fr native   6.56 cm SL male/unsexed  Found in the upper and middle course of rio Paraguaçu which have several relatively small tributaries entering its margins. Recorded from seven tributaries of rio São José and Santo Antônio, two of the main tributaries of the upper course of rio Paraguaçu (Ref. 75036). - 
Characidae Moenkhausia dichroura (Kner, 1858) Fr native  Lambari (Portuguese), Lambari-corintiano (Portuguese), Piaba do rabo preto (Portuguese)   10.00 cm SL male/unsexed  Recorded from rio Pardo basin, Município de Ribeirão Preto, São Paulo, LIRP 250 (Ref. 46237). Also Ref. 4537. + 
Characidae Moenkhausia diktyota Lima & Toledo-Piza, 2001 Fr native  Lambari (Portuguese), Tumuapé (Portuguese), Tuniupe (Portuguese)  5.24 cm SL male/unsexed  Type locality, near Santa Isabel do Rio Negro, igarapé at São João, rio Negro, Amazonas. - 
Characidae Moenkhausia doceana (Steindachner, 1877) Fr native  Lambari (Portuguese)   7.70 cm SL male/unsexed  Found in the Mucuri and Doce River basins (Ref. 38376). Recorded from rio Bamburral, São Mateus, Espírito Santo, MZUSP 54777 (Ref. 46237). Also Ref. 598. - 
Characidae Moenkhausia eurystaenia Marinho, 2010 Fr native   3.68 cm SL male/unsexed  Known from Rio Ronuro drainage, upper rio Xingu basin (Ref. 85160). - 
Characidae Moenkhausia forestii Benine, Mariguela & Oliveira, 2009 Fr native    3.79 cm SL male/unsexed  Known from Rio Paraguay drainage, rio Baía (upper rio Paraná system), and rio Paraná (Ref. 81199). - 
Characidae Moenkhausia gracilima Eigenmann, 1908 Fr native  Lambari (Portuguese)  5.90 cm SL male/unsexed  Found in the Amazon River basin (Ref. 38376). Type locality: Villa Bella; Serpa, Amazon R. (Ref. 26282). Recorded from Igarape connecting rio Solimoes and blackwater lake west of Coari, Amazonas, USNM 310357 (Ref. 46237). - 
Characidae Moenkhausia grandisquamis (Müller & Troschel, 1845) Fr native  Lambari (Portuguese)   10.00 cm SL male/unsexed  Occurs in the Amazon basin (Ref. 12225); recorded from Rio Marauiá, MZUSP 30267 (Ref. 46237) and Machado river basin + 
Characidae Moenkhausia hasemani Eigenmann, 1917 Fr native  Lambari (Portuguese)  4.50 cm SL male/unsexed  Known from the lower Tapajós River basin (Ref. 38376). Type locality: Santarém, Amazon R., Pará, Brazil (Ref. 26282). - 
Characidae Moenkhausia heikoi Géry & Zarske, 2004 Fr native   8.70 cm TL male/unsexed  Found in the rio Xingu basin, Altamira, Pará (Ref. 96859). Type locality, Rio Iriri, a left-hand tributary of the Rio Xingú well above Altamira, at edge of island between Rio Novo and Igarapé Grota, ca 10 km below mouth of R. Novo, Para, ca 4°25'S, 53°40'W (Ref. 56787). + 
Characidae Moenkhausia hemigrammoides Géry, 1965 Fr native    4.00 cm SL male/unsexed   + 
Characidae Moenkhausia hysterosticta Lucinda, Malabarba & Benine, 2007 Fr native    4.54 cm SL male/unsexed  Known from the middle portions of the Rio Tocantins in Porto Nacional, Ipueiras and Lageado (Ref. 58760). - 
Characidae Moenkhausia icae Eigenmann, 1908 Fr native   4.16 cm SL male/unsexed  Type locality, Rio Iça, Amazonas (Ref. 85815). - 
Characidae Moenkhausia intermedia Eigenmann, 1908 Fr, Fi native  Lambari (Portuguese), Lambari-corintiano (Portuguese), Piqui (Portuguese)   8.00 cm SL male/unsexed  Recorded from Caracu and Sao Pedro streams, tributaries of the Paraná river (Ref. 26076); from the Amazon basin and Paraguay and Paranagua rivers (Ref. 598); including lagoa do Diogo, Estação Ecológica de Jataí, Luis Antônio, São Paulo, LIRP 346 (Ref. 46237). Found in Piracicaba (Ref. 50076) and Acre river basins (Ref. 97592). Also Ref. 31923. + 
Characidae Moenkhausia jamesi Eigenmann, 1908 Fr native  Lambari (Portuguese)   6.80 cm SL male/unsexed  Found in the Amazon River basin (Ref. 38376). Type locality, Iça; Obidos; Lago do Maximo; Tajapuru, Amazon River (Ref. 26282). Also Ref. 598. - 
Characidae Moenkhausia justae Eigenmann, 1908 Fr native  Lambari (Portuguese)  6.00 cm SL male/unsexed  Found in the Amazon River basin (Ref. 38376). Recorded from Rio Branco, próximo de Viruá, Roraima (Ref. 46237). Also Ref. 598. - 
Characidae Moenkhausia lata Eigenmann, 1908 Fr native  Lambari (Portuguese)   8.00 cm SL male/unsexed  Found in the Tapajós River basin (Ref. 38376). Type locality: N. part of Rio Tapajós, Pará, Brazil. - 
Characidae Moenkhausia latissima Eigenmann, 1908 Fr native  Lambari (Portuguese)  9.20 cm SL male/unsexed  Known from the upper Amazon River near Tabatinga (Ref. 38376). Also Ref. 598. - 
Characidae Moenkhausia lepidura (Kner, 1858) Fr native  Rabo de fogo (Portuguese)   10.50 cm TL male/unsexed  Recorded from Rio Urubaxi, rio Negro basin, Amazonas, MZUSP 34627 (Ref. 46237). + 
Characidae Moenkhausia levidorsa Benine, 2002 Fr native   6.42 cm SL male/unsexed  Type locality, Núcleo Aripuanã, Igarapé do Aeroporto, Furo Bahia, above cachoeira de Dardanelos, ca. 10°10'S, 59°25'W, Mato Grosso State (Ref. 46237). Found in the middle Tapajós River basin (Ref. 38376). - 
Characidae Moenkhausia lineomaculata Dagosta, Marinho & Benine, 2015 Fr native   6.78 cm SL male/unsexed  Known from the rio Juruena basin, upper rio Tapajós basin, Mato Grosso State (Ref. 104871). - 
Characidae Moenkhausia lopesi Britski & de Silimon, 2001 Fr native   3.85 cm SL male/unsexed  Known from Paraguay River basin (Ref. 38376). - 
Characidae Moenkhausia loweae Géry, 1992 Fr native  Lambari (Portuguese)  7.50 cm TL male/unsexed  Found in the Araguaia River basin (Ref. 38376). Museum: Rio das Mortes at Xavantina, Mato Grosso, MZUSP 44560 (holotype of M. loweae, 5.25 cm SL) (Ref. 27925). - 
Characidae Moenkhausia megalops (Eigenmann, 1907) Fr native  Lambari (Portuguese)  5.00 cm SL male/unsexed  Recorded from the Amazon (Ref. 598). Also Ref. 26282. + 
Characidae Moenkhausia melogramma Eigenmann, 1908 Fr native  Lambari (Portuguese)  4.00 cm SL male/unsexed  Found in the upper Amazon River basin (Ref. 38376). - 
Characidae Moenkhausia miangi Steindachner, 1915 Fr native   8.90 cm SL male/unsexed  Found in the upper Branco River basin (Ref. 38376). - 
Characidae Moenkhausia mikia Marinho & Langeani, 2010 Fr native    7.83 cm SL male/unsexed  Seems to be distributed throughout the Amazon basin (Ref. 85074). Found in Machado river basin (Ref. 97589). - 
Characidae Moenkhausia mutum Dagosta & Marinho, 2016 Fr native   6.53 cm SL male/unsexed  Found in rio Arinos drainage, tributary of rio Juruena, upper rio Tapajós basin, Mato Grosso State (Ref. 109750). Status of threat: Least Concern (LC) following the International Union for Conservation of Nature (IUCN) categories and criteria (Ref. 109750). - 
Characidae Moenkhausia newtoni Travassos, 1964 Fr native  Lambari (Portuguese)  2.70 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38376). - 
Characidae Moenkhausia nigromarginata Costa, 1994 Fr native  Lambari (Portuguese)  5.30 cm SL male/unsexed  Museum: small stream, tributary to Rio Cravari near road MT-170, ca. 10 km north of Campo Novo do Parecis, Rio Tapajós basin, Mato Grosso, MZSUP 45289 (Ref. 27925). Also Ref. 46237. - 
Characidae Moenkhausia oligolepis (Günther, 1864) Fr native  Pequira (Portuguese), Lambari olho-de-fogo (Portuguese), Pira miri (Portuguese)   10.00 cm SL male/unsexed  Occurs in the Amazon (Ref. 12225), Machado (Ref. 97589) and Acre River basins (Ref. 97592). Recorded from Rio Cupixi, Amapá, MZUSP 30287 (Ref. 46237), Also Ref. 4537. + 
Characidae Moenkhausia pankilopteryx Bertaco & Lucinda, 2006 Fr native   9.67 cm SL male/unsexed   - 
Characidae Moenkhausia parecis Ohara & Marinho, 2016 Fr native   7.79 cm SL male/unsexed  Found only in its type locality, a headwater tributary of igarapé Piracolina, itself a tributary of the upper rio Machado at Chapada dos Parecis, rio Madeira basin, about 9 km south of Vilhena, near the border of Rondônia and Mato Grosso States (Ref. 109906). Might be considered as Vulnerable (D2), based on its occupation area (AOO) of less than 20 km2 and the plausible future threats (agricultural development and expansion of Vilhena town around its very restricted distribution) that could lead the species to become critically endangered or extinct (Ref. 109906). - 
Characidae Moenkhausia petymbuaba Lima & Birindelli, 2006 Fr native   5.59 cm SL male/unsexed  Found only in the upper Rio Curuá, a tributary of the Rio Iriri, at the Serra do Cachimbo, Rio Xingu basin (Ref. 56956). - 
Characidae Moenkhausia phaeonota Fink, 1979 Fr native  Piaba (Portuguese), Lambari (Portuguese)  5.60 cm SL male/unsexed  Museum: shores of an island "below Rio dos Peixes", Rio Arinos, Juruena-Tapajós drainage, Mato Grosso, MZUSP 13793 (holotype of M. phaeonota, 3.26 SL) (Ref. 27925). Also Ref. 46237. - 
Characidae Moenkhausia pirauba Zanata, Birindelli & Moreira, 2010 Fr native   9.92 cm SL male/unsexed  Type locality, Estado do Mato Grosso, Município de Campinápolis, Rio Sucuri, tributary of Rio Culuene, Rio Xingu basin, MZUSP 97741 (holotype of Moenkhausia pirauba, 6.92 cm SL). Known from tributaries in the upper portions of the Rio Xingu basin, from the Rio Von Den Steinen west to the Rio Suiá-Miçú and east in the Mato Grosso State, and the Rio Treze de Maio, tributary of the Rio Curúa, Rio Iriri drainage in Par´a State; also in the Rio Arinos and Rio Teles Pires and its tributaries in the upper Rio Tapajós basin (Ref. 83482). Reported from Machado river basin (Ref. 97589). - 
Characidae Moenkhausia plumbea Sousa, Netto-Ferreira & Birindelli, 2010 Fr native   4.95 cm SL male/unsexed  Type locality, Pará, Novo Progresso, tributary to rio Braço Norte, at bridge of BR 163 road near Air Force Base, rio Peixoto de Azevedo, rio Teles Pires drainage, rio Tapajós basin, MZUSP 99415 (holotype of Moenkhausia plumbea, 4.95 cm SL) (Ref. 84462). - 
Characidae Moenkhausia pyrophthalma Costa, 1994 Fr native  Lambari olho-de-fogo (Portuguese)  3.40 cm SL male/unsexed  Museum: stream crossing road between Agua Boa and Cocalinho, Rio Araguaia-Tocantins basin, Mato Grosso, MZUSP 45290 (Ref. 27925). Also Ref. 46237. + 
Characidae Moenkhausia rubra Pastana & Dagosta, 2014 Fr native   5.43 cm SL male/unsexed  Found in the rio Juína and rio Juruena of the rio Juruena basin, upper rio Tapajós drainage in Mato Grosso State (Ref. 96859). - 
Characidae Moenkhausia sanctaefilomenae (Steindachner, 1907) Fr native  Pequira (Portuguese), Lambari (Portuguese), Lambari olho-de-fogo (Portuguese), Piaba (Portuguese)   7.00 cm SL male/unsexed  Recorded from Caracu and Sao Pedro streams, tributaries of the Paraná river (Ref. 26076); lagoon near rio Cuiabá, Mato Grosso, LIRP 717 (Ref. 46237). Also Ref. 4537. + 
Characidae Moenkhausia surinamensis Géry, 1965 Fr native   10.30 cm SL male/unsexed  Present in the Oyapock River which forms the border between Brazil and French Guiana (Ref. 12225). - 
Characidae Moenkhausia takasei Géry, 1964 Fr native  Lambari (Portuguese), Jaqueta preta (Portuguese)  3.30 cm SL male/unsexed   - 
Characidae Moenkhausia tergimacula Lucena & Lucena, 1999 Fr native  Lambari (Portuguese), Piaba (Portuguese)   5.20 cm SL male/unsexed    - 
Characidae Moenkhausia tridentata Holly, 1929 Fr native  Lambari (Portuguese)   Recorded from the Amazon (Ref. 26282). - 
Characidae Moenkhausia uirapuru Ohara & Lima, 2015 Fr endemic   5.97 cm SL male/unsexed  Currently only known from two headwater tributaries of the upper rio Guaporé, Mato Grosso State, Brazil (Ref. 119236). - 
Characidae Moenkhausia venerei Petrolli, Azevedo-Santos & Benine, 2016 Fr native   3.88 cm SL male/unsexed  Found in streams around Barra do Garças, rio Araguaia basin, and from Araguaçu, rio Araguaia basin (Ref. 107661). - 
Characidae Moenkhausia xinguensis (Steindachner, 1882) Fr native  Piaba (Portuguese), Lambari (Portuguese)  10.30 cm TL male/unsexed  Recorded from rio Xingu, Cachoeira do Espelho, Pará (Ref. 46237). Also Ref. 598. - 
Polycentridae Monocirrhus polyacanthus Heckel, 1840 Fr native  Peixe-folha (Portuguese), Pirá-caá (Portuguese), Pirá-cará (Portuguese)   8.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 50082). Also Ref. 4537. + 
Rivulidae Mucurilebias leitaoi (da Cruz & Peixoto, 1992) Fr endemic    3.00 cm TL male/unsexed  Known from the Mucurí River basin (Ref. 36579). Also Ref. 27139. + 
Mugilidae Mugil cephalus Linnaeus, 1758 Fr, Br, M native  Curemà (Portuguese), Cambiro (Portuguese), Curimã (Portuguese), Curimã-í (Portuguese), Tainha (Portuguese), Tainhota (Portuguese), Tamaratana (Portuguese), Tamatarana (Portuguese), Tapiara (Portuguese), Tapuji (Portuguese), Urichoa (Portuguese)  100.00 cm SL male/unsexed   + 
Mugilidae Mugil curema Valenciennes, 1836 Fr, Br, M, Aq native  Caíca (Portuguese), Mondego (Portuguese), Parati (Portuguese), Parati guaçú (Portuguese), Parati-olho-de-fogo (Portuguese), Paratibu (Portuguese), Paratiguera (Portuguese), Pratiqueira (Portuguese), Pratiquera (Portuguese), Sassaiuba (Portuguese), Saúna (Portuguese), Saúna-olho-de-fogo (Portuguese), Solé (Portuguese), Tainha (Portuguese), Tainha pitiu (Portuguese), Tainha sajuba (Portuguese), Tainha-de-olho-amarelo (Portuguese), Tainha-do-olho-amarelo (Portuguese), Tainha-do-olho-preto (Portuguese), Tainha-parati (Portuguese), Tainha-verdadeira (Portuguese)   91.00 cm TL male/unsexed 27.5 TL Located at the southernmost tip of the Bombinhas peninsula, southern Brazil (Ref. 55758). Also Ref. 7251, 13442, 26340, 27188. + 
Mugilidae Mugil liza Valenciennes, 1836 Fr, Br, M, Fi native  Cambão (Portuguese), Cacatão (Portuguese), Cacetão (Portuguese), Cambiro (Portuguese), Chaveta (Portuguese), Curimã (Portuguese), Curimã-aiva (Portuguese), Curimaí (Portuguese), Meloso (Portuguese), Parati (Portuguese), Sauna (Portuguese), Saúna (Portuguese), Sauna-açu (Portuguese), Saúna-açu (Portuguese), Tainha (Portuguese), Taínha (Portuguese), Tainha de rio (Portuguese), Tainha-curimã (Portuguese), Tainha-de-corrida (Portuguese), Tainha-de-corso (Portuguese), Tainha-de-entrada (Portuguese), Tainha-de-rio (Portuguese), Tainha-pau (Portuguese), Tainha-seca (Portuguese), Tainha-verdadeira (Portuguese), Tainhota (Portuguese), Tamatarana (Portuguese), Tapiara (Portuguese), Tapugi (Portuguese), Urichoca (Portuguese)   80.00 cm TL male/unsexed ;69.00 cm TL female 35 TL Ranges from Rio de Janeiro southward. Commonly found in markets throughout the region, but much more common south of São Paulo (Ref. 9062). Also reported from the southernmost tip of the Bombinhas peninsula, southern Brazil (Ref. 55758). Also Ref. 26375. + 
Mugilidae Mugil trichodon Poey, 1875 Fr, Br, M native  Parati (Portuguese), Negrão (Portuguese), Saúna (Portuguese), Saúna-parati (Portuguese), Tainha (Portuguese), Tainha olho-preto (Portuguese), Tainha-roliça (Portuguese), Tamaratana (Portuguese)  46.00 cm TL male/unsexed  Also Ref. 7251. + 
Serrasalmidae Mylesinus paraschomburgkii Jégu, Santos & Ferreira, 1989 Fr native  Pacu cana (Portuguese), Pacu (Portuguese)  35.00 cm SL male/unsexed  Known from the left tributaries of the lower Amazon River, Araguari River (Ref. 39031). Type locality: Rio Trombetas, downstream of Cachoeira Vira-Mundo, Brazil. + 
Serrasalmidae Mylesinus paucisquamatus Jégu & Santos, 1988 Fr native  Curupeté (Portuguese), Pacu (Portuguese)   33.30 cm SL male/unsexed ;30.50 cm SL female  Museum: Rio Tocantins: Jatobal, MZUSP 38832; Itupiranga, MZUSP 38831 (Ref. 27925). Maybe threatened by extinction due to its restricted distribution in the rapids of Rio Tocantins, a biotope currently destroyed by hydroelectric power plants (Ref. 85327). + 
Serrasalmidae Mylesinus schomburgkii Valenciennes, 1850 Fr native  Pacu (Portuguese)     - 
Serrasalmidae Myleus altipinnis (Valenciennes, 1850) Fr native  Pacu (Portuguese)    Known from the São Francisco River basin (Ref. 39031). - 
Serrasalmidae Myleus micans (Lütken, 1875) Fr native  Pacu (Portuguese), Pacamão (Portuguese), Pacu azul (Portuguese)   27.60 cm SL male/unsexed  Known from Rio São Francisco basin (Ref. 39031). Also Ref. 598. + 
Serrasalmidae Myleus pacu (Jardine, 1841) Fr, Fi misidentification  Pacu dente (Portuguese), Pacu dente seco (Portuguese), Pacu lombo de foia (Portuguese)  20.00 cm TL male/unsexed  Occurence in the Amazon Basin in Ref. 12225 refers to Tometes trilobatus. Occurrence in the country is not confirmed (Ref. 39031). + 
Serrasalmidae Myleus setiger Müller & Troschel, 1844 Fr native  Pacu dente-seco (Portuguese), Pacu (Portuguese)   27.20 cm SL male/unsexed ;28.70 cm SL female    + 
Serrasalmidae Myloplus arnoldi Ahl, 1936 Fr native  Pacu branco (Portuguese)  33.00 cm TL male/unsexed  Known from the Amazon, Xingu and Tocantins River basins (Ref. 39031). + 
Serrasalmidae Myloplus asterias (Müller & Troschel, 1844) Fr native  Pacu (Portuguese), Pacu branco (Portuguese), Pacu galo (Portuguese)   25.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39031). Type locality: Rio Gurupi at Chatao, Brazil. + 
Serrasalmidae Myloplus levis (Eigenmann & McAtee, 1907) Fr native  Coxa de negro (Portuguese), Coxa-de-nego (Portuguese), Pacu peva (Portuguese), Pacu-peva (Portuguese)   20.00 cm SL male/unsexed  Found in Pantanal (Ref. 81048). + 
Serrasalmidae Myloplus lobatus (Valenciennes, 1850) Fr native    24.50 cm SL male/unsexed    - 
Serrasalmidae Myloplus lucienae Andrade, Ota, Bastos & Jégu, 2016 Fr native   33.75 cm SL male/unsexed  Known from the rio Negro and its main tributaries, such as the rio Arirará, rio Carabinani, rio Cuiuni, rio Curicuriari and rio Daraá, all belonging to the rio Negro basin, Amazonas State (Ref. 114774).. - 
Serrasalmidae Myloplus nigrolineatus Ota, Machado, Andrade, Collins, Farias & Hrbek, 2020 Fr native  abundant (always seen in some numbers) 23.77 cm SL male/unsexed  Type locality of Myloplus nigrolineatus, Amazonas State, ca. 60 km south of Manaus, lago Tracajá, tributary of rio Juma, rio Amazonas basin. Collected from the following localities: clearwater rivers of the Aripuanã, rio Água Boa do Univini (rio Branco), Nhamundá, Tapajós, Tocantins, and Uatumã rivers and the extremely acidic oligotrophic blackwaters of rio Negro basin, rio Jutaí, Pauapixuna lake (rio Juruá), Tapauá lake (rio Purus), Serpa lake (rio Amazonas), and rio Maués-Açu (Ref. 123127).

Conservation status: It is common and naturally abundant, widely distributed within black- and clearwater Amazonian rivers and with no specific threats detected. Thus, it can be tentatively categorized as Least Concern (LC) according to the International Union for Conservation of Nature (IUCN) categories and criteria (IUCN Standards and Petitions Subcommittee, 2017) (Ref. 123127). 

- 
Serrasalmidae Myloplus rubripinnis (Müller & Troschel, 1844) Fr native  Pacu branco (Portuguese), Pacu (Portuguese), Pacu de corredeira (Portuguese), Pacu tinga (Portuguese), Pacuzinho (Portuguese)   41.50 cm TL male/unsexed  Present in the Oyapock River which forms the border between French Guaina and Brazil (Ref. 12225). + 
Serrasalmidae Myloplus schomburgkii (Jardine, 1841) Fr, Fi native  Pacu jumento (Portuguese), Pacu (Portuguese), Pacu cadete (Portuguese), Pacu ferrado (Portuguese), Pacu miri (Portuguese), Pacu piranga (Portuguese), Uitu (Portuguese), Yavita (Portuguese)  42.00 cm SL male/unsexed   + 
Serrasalmidae Myloplus ternetzi (Norman, 1929) Fr native   23.10 cm SL male/unsexed  Occurs in the state of Para (Ref. 27188). + 
Serrasalmidae Myloplus tiete (Eigenmann & Norris, 1900) Fr native  Pacu peva (Portuguese), Pacu prata (Portuguese)   16.30 cm SL male/unsexed  Type locality: Piracicaba, São Paulo, Brazil. - 
Serrasalmidae Myloplus torquatus (Kner, 1858) Fr, Fi native  Pacu branco (Portuguese), Pacu miri (Portuguese)   29.40 cm SL male/unsexed ;27.90 cm SL female  Type locality: Rio Branco, Marabitanos, Amazonas, Brazil. Found regularly in fish markets in Santarém. + 
Serrasalmidae Myloplus zorroi Andrade, Jégu & Giarrizzo, 2016 Fr native    Known from Aripuanã and Roosevelt rivers, tributaries of the Rio Madeira basin (Ref. 114773). - 
Serrasalmidae Mylossoma albiscopum (Cope, 1872) Fr native   24.20 cm SL male/unsexed  Known from Rio Amazonas basin (Amapá, Pará, Roriama), Rio Madeira basin. (Amazonas, Rondonia) and Rio Negro basin (Amazonas), Rio Purus basin (Acre, Amazonas), Rio Solimões basin (Amazonas), and Rio Tapajós basin (Pará) (Ref. 117280). - 
Serrasalmidae Mylossoma aureum (Spix & Agassiz, 1829) Fr, Fi native  Pacu comum (Portuguese), Pacu manteiga (Portuguese)   20.00 cm TL male/unsexed  Known from the Amazon River (Ref. 39031), Rio Madeira basin, Rio Purus basin, Rio Solimões basin, and Rio Xingu basin:Acre, Amazonas, Pará: and Rondônia (Ref. 117280). Found regularly in fish markets in Santarém (Ref. 12202). + 
Serrasalmidae Mylossoma duriventre (Cuvier, 1818) Fr native  Pacu peva (Portuguese), Pacu branco (Portuguese), Pacu chico (Portuguese), Pacu comum (Portuguese), Pacu mafurá (Portuguese), Pacu manteiga (Portuguese), Pacu mirim (Portuguese), Pacu prata (Portuguese), Pacu-peva (Portuguese), Tambaqui (Portuguese)   25.00 cm SL male/unsexed    + 
Serrasalmidae Mylossoma unimaculatum (Steindachner, 1908) Fr native   25.60 cm male/unsexed  Type locality of Mylossoma unimaculatum. Known from the Amazon basin and restricted to the rio Tocantins-Araguaia system. With its migratory behavior, this species was reported to be one of the most affected species after the establishment of the Tucuruí reservoir, since the river impoundment prevents the upstream reproductive migration and also limits the recolonization of downstream stretches (Ref. 117280). - 
Heptapteridae Myoglanis koepckei Chang, 1999 Fr native    5.87 cm SL male/unsexed   - 
Ophichthidae Myrophis plumbeus (Cope, 1871) Fr, M native   46.50 cm TL male/unsexed  MZC 61522-539 (Ref. 080860). - 
Cichlidae Nannacara adoketa Kullander & Prada-Pedreros, 1993 Fr endemic    4.90 cm SL male/unsexed  Known from the middle Negro River basin of the Amazon River basin (Ref. 36377). + 
Cichlidae Nannacara taenia Regan, 1912 Fr endemic    5.00 cm SL male/unsexed  Found near Belem, Para State (Ref. 36377). + 
Loricariidae Nannoplecostomus eleonorae Ribeiro, Lima & Pereira, 2012 Fr native   2.17 cm SL male/unsexed ;2.22 cm SL female 1.69 SL Type locality. Known only from small tributaries of the Rio São Domingos and from the Rio das Pedras, both tributaries of the Rio Paranã, upper Rio Tocantins basin, Goiás State (Ref. 92524). - 
Loricariidae Nannoptopoma sternoptychum Schaefer, 1996 Fr native    3.30 cm SL male/unsexed  Known from lowland reaches of the Amazon River and tributaries below 200 m elevation. + 
Lebiasinidae Nannostomus anduzei Fernandez & Weitzman, 1987 Fr native   1.60 cm SL male/unsexed   + 
Lebiasinidae Nannostomus beckfordi Günther, 1872 Fr native  Torpedinho-doudado (Portuguese), Torpedinho (Portuguese), Torpedinho dourado (Portuguese)   6.50 cm SL male/unsexed  Present in the Amazon and Rio Negro (Ref. 12225). + 
Lebiasinidae Nannostomus bifasciatus Hoedeman, 1954 Fr, Fi, Aq native  Torpedinho (Portuguese)  3.40 cm SL male/unsexed  Present in the Oyapock River which forms the border between Brazil and French Guiana (Ref. 12225). + 
Lebiasinidae Nannostomus britskii Weitzman, 1978 Fr, Fi native   2.40 cm SL male/unsexed ;2.41 cm SL female  Known from two localities, the type locality and Aripuana River, Castanhal Island, Amazonas, Brazil (Ref. 37104). Museum: Igarapé of Lago José-Açu, Parantins, Amazon R., Amazonas, MZUSP 7795 (holotype of N. britskii, 2.28 cm SL, male) (Ref. 27925). + 
Lebiasinidae Nannostomus digrammus (Fowler, 1913) Fr, Fi native    2.76 cm SL male/unsexed  Recorded from the Madeira River and the lower and middle Amazon River (Ref. 598). Also Ref. 37104. + 
Lebiasinidae Nannostomus eques Steindachner, 1876 Fr native  Bengalinha (Portuguese), Lápis (Portuguese)   5.00 cm TL male/unsexed  Known from the Amazon River (Ref. 37104). + 
Lebiasinidae Nannostomus erythrurus (Eigenmann, 1909) Fr native   2.88 cm SL male/unsexed  Known from rio Corumbiara, Guaporé (Ref. 94659). - 
Lebiasinidae Nannostomus grandis Zarske, 2011 Fr native   4.62 cm SL male/unsexed   - 
Lebiasinidae Nannostomus limatus Weitzman, 1978 Fr, Fi native   3.60 cm SL male/unsexed  Known from the Amazon River basin near Santarém (Ref. 37104). Museum: tributary of Lago Mapará, near Santarém, Pará, Amazon River, MZUSP 8486 (holotype of N. limatus, 2.99 cm SL, male) (Ref. 27925). - 
Lebiasinidae Nannostomus marginatus Eigenmann, 1909 Fr, Fi native  Torpedinho (Portuguese)   3.50 cm TL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Lebiasinidae Nannostomus marilynae Weitzman & Cobb, 1975 Fr, Fi native   5.00 cm TL male/unsexed  Recorded from Rio Negro (Ref. 598). Also Ref. 4537, 37104. + 
Lebiasinidae Nannostomus nitidus Weitzman, 1978 Fr, Fi native   3.50 cm SL male/unsexed  Museum: Igarapé Candiru-Mirim, Rio Capim, Pará, MZUSP 12920 (holotype of N. nitidus, 3.47 cm SL, male) (Ref. 27925). + 
Lebiasinidae Nannostomus trifasciatus Steindachner, 1876 Fr native  Torpedinho (Portuguese), Zepelim (Portuguese)   3.60 cm SL male/unsexed  Known from the Amazon, Negro (Ref. 37104) and Machado (Ref. 97589) River basins. + 
Lebiasinidae Nannostomus unifasciatus Steindachner, 1876 Fr native  Peixe lápis (Portuguese)   3.80 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Loricariidae Nannoxyropsis acicula Delapieve, Lehmann A & Reis, 2018 Fr native   3.35 cm SL male/unsexed  Occurs in the tributaries to the lower rio Tapajós (Ref. 116855). Status of threat: Least concern (LC) based on the following: unfragmented population; continuing decline cannot be inferred; and no eminent threats are detected (Ref. 116855). - 
Doradidae Nemadoras cristinae Sabaj Pérez, Arce H., Sousa & Birindelli, 2014 Fr native   12.39 cm SL male/unsexed  Known from the middle Amazonas (Solimões) from mouth of Putumayo/Iça to that of Madeira (Ref. 96153). - 
Doradidae Nemadoras elongatus (Boulenger, 1898) Fr native    16.50 cm SL male/unsexed  Found in the Rio Jurua (Ref. 6868). Known from the Amazon River (Ref. 37054). - 
Doradidae Nemadoras hemipeltis (Eigenmann, 1925) Fr native    16.30 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Doradidae Nemadoras humeralis (Kner, 1855) Fr native  Corno (Portuguese)   16.30 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Characidae Nematocharax costai Bragança, Barbosa & Mattos, 2013 Fr native   4.98 cm SL male/unsexed  Known from the Cambiriba Stream, Balneário Guaíra, middle Contas River basin in Bahia, northeastern Brazil (Ref. 93323). - 
Characidae Nematocharax venustus Weitzman, Menezes & Britski, 1986 Fr native    5.10 cm SL male/unsexed ;3.54 cm SL female  Museum: Rio Jequitinhonha at Itaobim, Minas Gerais, Município Medina, MZUSP 5131 (holotype of N. venustus, 5.05 cm SL, male) (Ref. 27925). Also Ref. 38376. - 
Rivulidae Nematolebias catimbau Costa, Amorim & Aranha, 2014 Fr native   4.57 cm SL male/unsexed ;3.36 cm SL female  Found in the Catimbau river floodplain, Saquarema lagoon system in Município de Saquarema, Estado do Rio de Janeiro (Ref. 99536). - 
Rivulidae Nematolebias papilliferus Costa, 2002 Fr native   7.00 cm SL male/unsexed  Known from the coastal plain areas between Inoã, laguna de Maricá system, and Sampaio Correia, laguna de Saquarema system, Estado do Rio de Janeiro, SE Brazil. Type locality, temporary pool close to a small stream of laguna de Maricá system, Inoã, Estado do Rio de Janeiro (Ref. 42934). + 
Rivulidae Nematolebias whitei (Myers, 1942) Fr endemic  Cinolébias (Portuguese), Peixe anual (Portuguese)   8.00 cm TL male/unsexed  Known from the coastal plain area between Bom Sucesso, laguna de Araruama system, and Rio das Otras, coastal plains adjacent to the mouth of rio São João, estado do Rio de Janeiro, SE Brazil (Ref. 42934). Also 27139, 36579. + 
Heptapteridae Nemuroglanis furcatus Ribeiro, Pedroza & Rapp Py-Daniel, 2011 Fr native    4.67 cm male/unsexed  Found in streams of the rio Guariba, a clear water tributary of the rio Aripuanã, rio Madeira basin (Ref. 86655). - 
Heptapteridae Nemuroglanis lanceolatus Eigenmann & Eigenmann, 1889 Fr native   3.81 cm SL male/unsexed  Known from Solimões River basin, a tributary of the Amazon River system (Ref. 55662). Type locality: Rio Jutahy, trib. of Rio Solimoes, Amazonas, Brazil (Ref. 26282, 6868). - 
Heptapteridae Nemuroglanis pauciradiatus Ferraris, 1988 Fr native    3.25 cm SL male/unsexed  Occurs in the Negro and Sanabani River basins, a left bank tributary of the Amazon River (Ref. 55662). Also Ref. 36914. - 
Rivulidae Neofundulus acutirostratus Costa, 1992 Fr endemic   7.50 cm TL male/unsexed  Known from the Das Velhas River basin (Ref. 36579). May be extinct (Ref. 27139). - 
Rivulidae Neofundulus aureomaculatus Costa, 2015 Fr native   4.66 cm SL male/unsexed ;5.28 cm SL female  Known from Aquidauana river drainage, Paraguay river basin in Mato Grosso do Sul (Ref. 101435). - 
Rivulidae Neofundulus guaporensis Costa, 1988 Fr endemic   3.00 cm TL male/unsexed  Known from the Guaporé River basin (Ref. 36579). - 
Rivulidae Neofundulus paraguayensis (Eigenmann & Kennedy, 1903) Fr native    7.00 cm TL male/unsexed  Known from the Paraguay River (Ref. 36579). + 
Rivulidae Neofundulus parvipinnis Costa, 1988 Fr endemic   6.00 cm TL male/unsexed  Known from the Paraguay River basin (Ref. 36579). Also Ref. 27139. - 
Rivulidae Neofundulus rubrofasciatus Costa, 2015 Fr native   4.63 cm SL male/unsexed ;3.38 cm SL female  Occurs in two localities of the Miranda river drainage in Mato Grosso do Sul: one locality is located in an almost plain area continuous to the floodplains of the Salobra river, a tributary of the Miranda river; the other locality is in the Miranda river floodplains, near the town of Miranda (Ref. 101435). - 
Loricariidae Neoplecostomus bandeirante Roxo, Oliveira & Zawadzki, 2012 Fr native   10.99 cm SL male/unsexed   - 
Loricariidae Neoplecostomus botucatu Roxo, Oliveira & Zawadzki, 2012 Fr native   10.22 cm SL male/unsexed   - 
Loricariidae Neoplecostomus corumba Zawadzki, Pavanelli & Langeani, 2008 Fr native   8.06 cm SL male/unsexed  Type locality, Goiás State, Corumbaíba, Córrego Gameleira, affluent of Rio Corumbá, Rio Paranaíba basin, DZSJRP 6713 (holotype of Neoplecostomus corumba, 7.83 cm Sl, male) (Ref. 75575). - 
Loricariidae Neoplecostomus doceensis Roxo, Silva, Zawadzki & Oliveira, 2014 Fr native   10.11 cm SL male/unsexed  Found in thirteen localities of the rio Doce Basin, Minas Gerais State: one at rio Gualaxo do Norte, one at rio Gualaxo do Sul, one at rio José Pedro, one at rio Piranga, three at rio Manhuaçu, one at rio Suaçuí Pequeno and five at rio Xopotó (Ref. 106072). - 
Loricariidae Neoplecostomus espiritosantensis Langeani, 1990 Fr native   10.30 cm SL male/unsexed  Found in Jacu and São Lourenço rivers, eastern slope of Serra do Mar (Ref. 37046). Type locality: Rio Jacu (braço sul), Victor Hugo, Mun. de Domingos Martins, ES, Brazil (Ref. 37046). - 
Loricariidae Neoplecostomus franciscoensis Langeani, 1990 Fr native  Cascudo (Portuguese)  10.78 cm SL male/unsexed  Found in headwaters of Das Velhas and Paraopeba River basins, São Francisco River drainage (Ref. 37046). Regarded as threatened in the state of Minas Gerais (Ref. 26603). - 
Loricariidae Neoplecostomus granosus (Valenciennes, 1840) Fr questionable  Anhã (Portuguese)  8.60 cm SL male/unsexed  Occurrence uncertain. + 
Loricariidae Neoplecostomus jaguari Andrade & Langeani, 2014 Fr native   9.33 cm SL male/unsexed  Known from the ribeirão do Forja and from córrego Casca d’Antas, both tributaries from the rio Jaguari, sub-basin from the rio Piracicaba-Capivari- Jundiaí, rio Tietê drainage, upper rio Paraná basin (Ref. 97853). - 
Loricariidae Neoplecostomus langeanii Roxo, Oliveira & Zawadzki, 2012 Fr native   8.55 cm SL male/unsexed   - 
Loricariidae Neoplecostomus microps (Steindachner, 1877) Fr native    10.20 cm SL male/unsexed  Found in the Paraíba do Sul River basin (Ref. 37046). Type locality: Rio de Janeiro, Brazil (Ref. 26282, 6868). - 
Loricariidae Neoplecostomus paranensis Langeani, 1990 Fr native    9.30 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 37046). Type locality: Rio Cubatão, Faz. Santa Carlota, Cajurú, State of São Paulo, Brazil (Ref. 37046). - 
Loricariidae Neoplecostomus ribeirensis Langeani, 1990 Fr native   9.00 cm SL male/unsexed  Known from the Ribeira de Iguape River basin (Ref. 37046). Type locality: Riacho afluente do Rio Bananal, 7 km da rodovia Biguá-Iguape, SP, Brazil (Ref. 37046). - 
Loricariidae Neoplecostomus selenae Zawadzki, Pavanelli & Langeani, 2008 Fr native    10.17 cm SL male/unsexed  Type locality, upstream from the bridge at Ribeirão Grande to Intervales road, affluent of the Rio Paranapanema. Ribeirão das Batéias, Ribeirão Grande, São Paulo State, MZUSP 51889 (holotype of Neoplecostomus selenae, 10.17 cm SL, male) (Ref. 75575). - 
Loricariidae Neoplecostomus variipictus Bizerril, 1995 Fr native   9.02 cm SL male/unsexed  Known from the Paraíba do Sul River basin (Ref. 37046). - 
Loricariidae Neoplecostomus watersi Silva, Reia, Zawadzki & Roxo, 2019 Fr native   6.97 cm SL male/unsexed  Type locality of Neoplecostomus watersi, Goiás state, municipality of Aporé, Córrego da Cachoeira, Rio Correntes drainage, upper Rio Paraná basin (Ref. 119403). - 
Loricariidae Neoplecostomus yapo Zawadzki, Pavanelli & Langeani, 2008 Fr native   10.96 cm SL male/unsexed  Type-locality: Paraná State, Tibagi, Riacho Fortaleza (Fazenda Santo Amaro), affluent of Rio Yapó, Rio Tibagi basin, DZSJRP 6714 (holotype of Neoplecostomus yapo, 9.74 cm SL, male) (Ref. 75575). - 
Rivulidae Notholebias cruzi (Costa, 1988) Fr endemic    4.00 cm TL male/unsexed  Parana, São Paulo (Ref. 27139). - 
Rivulidae Notholebias fractifasciatus (Costa, 1988) Fr native    4.00 cm TL male/unsexed  Museum: marsh near Inoã, Maricá, Rio de Janeiro, MZUSP 36423. + 
Rivulidae Notholebias minimus (Myers, 1942) Fr, Fi, Or endemic    4.00 cm TL male/unsexed  Known in the vicinity of Rio de Janeiro. Also Ref. 4537. + 
Rivulidae Notholebias vermiculatus Costa & Amorim, 2013 Fr endemic    Known only from Saquarema lagoon system (Ref. 98301). + 
Trichomycteridae Ochmacanthus alternus Myers, 1927 Fr native   4.00 cm SL male/unsexed  Known from the Negro River basin (Ref. 39970). + 
Trichomycteridae Ochmacanthus batrachostomus (Miranda Ribeiro, 1912) Fr native    3.20 cm SL male/unsexed  Known from Paraguay River basin (Ref. 39970). - 
Trichomycteridae Ochmacanthus orinoco Myers, 1927 Fr native   4.60 cm SL male/unsexed  Known from the Negro River basin (Ref. 39970). + 
Trichomycteridae Ochmacanthus reinhardtii (Steindachner, 1882) Fr native  Candiru (Portuguese), Cambeva (Portuguese)   5.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39970). Type locality: Iça, Monte Alegre and Manacapuru, Amazonas, Brazil (Ref. 6868). + 
Atherinopsidae Odontesthes argentinensis (Valenciennes, 1835) Fr native  Peixe-rei (Portuguese), Mamarreis (Portuguese)  42.10 cm TL male/unsexed 13.8 TL Known from Santa Catarina, Iguape in São Paulo and Rio Grande do Sul. + 
Atherinopsidae Odontesthes bicudo Malabarba & Dyer, 2002 Fr native  Peixe-rei (Portuguese)   22.15 cm SL male/unsexed  Known from a group of partially isolated freshwater lakes northeast of the city of Osorio, namely lagoa Emboaba, lagoa Caconde, lagoa do Horacio and lagoa do Lessa (Ref. 47314). Occurs sympatrically with O. piquava in the lagoa Caconde (Ref. 47314). - 
Atherinopsidae Odontesthes humensis de Buen, 1953 Fr native  Peixe rei (Portuguese)   35.00 cm TL male/unsexed    + 
Atherinopsidae Odontesthes incisa (Jenyns, 1841) Fr, Br, M native  Mamarreis (Portuguese), Peixe-rei (Portuguese)  10.00 cm TL male/unsexed   + 
Atherinopsidae Odontesthes ledae Malabarba & Dyer, 2002 Fr native   20.25 cm SL male/unsexed  Occurs along all interconnected lakes southern to brackish water estuarine area of the rio Tramandai drainage in southern Brazil, from lagoa do Armazem through lagoa do Rincao das Eguas in the south. Further occurs in two partially isolated lakes south of the rio Tramandai drainage, namely lagoa do Cipo and lagoa da Solidao. Sympatric with O. argentinensis in the lagoa do Armazem and with Atherinella brasiliensis in the lagoa do Armazem and lagoa das Custodias (Ref. 47314). - 
Atherinopsidae Odontesthes mirinensis Bemvenuti, 1996 Fr native   14.84 cm SL male/unsexed  Known from Lagoa Mirim, RS. + 
Atherinopsidae Odontesthes orientalis de Buen, 1950 Fr native     - 
Atherinopsidae Odontesthes perugiae Evermann & Kendall, 1906 Fr native   28.30 cm TL male/unsexed   + 
Atherinopsidae Odontesthes piquava Malabarba & Dyer, 2002 Fr native   26.31 cm SL male/unsexed  Known from largest interconnected freshwater lakes of the rio Tramandai drainage. Recorded from lagoa Itapeva entering the mouth of rio Tres Forquilhas, in lagoa dos Quadros entering the mouth of rio Maquine, in lagoa Pinguela, lagoa do Peixoto and lagoa Caconde. Occurs sympatrically with O. bonariensis in lagoa Itapeva and lagoa dos Quadros and with O. bicudo in lagoa Caconde (Ref. 47314). - 
Atherinopsidae Odontesthes yucuman Wingert, Ferrer & Malabarba, 2017 Fr native  Peixe-rei (Portuguese)  16.87 cm SL male/unsexed  Known from the upper rio Uruguay and rio Passo Fundo (Ref. 116661). - 
Crenuchidae Odontocharacidium aphanes (Weitzman & Kanazawa, 1977) Fr native    1.65 cm SL male/unsexed  Type locality, Rio Negro, State of Amazonas, MZUSP 12978 (holotype of K. aphanes, 1.3 cm SL, male) (Ref. 13683). Known from the Amazon River (Ref. 37059) and in Acre, Rio Branco (Ref. 122685). Also Ref. 27925. + 
Pristigasteridae Odontognathus mucronatus Lacepède, 1800 Fr, Br, M native  Pelada (Portuguese), Arenque-branco (Portuguese), Arenque-falcão (Portuguese), Navalha (Portuguese), Sardinha (Portuguese), Sardinha-branca (Portuguese)   22.00 cm TL male/unsexed    + 
Characidae Odontostilbe avanhandava Chuctaya, Bührnheim & Malabarba, 2018 Fr native   7.07 cm SL male/unsexed  Type locality of Odontostilbe avanhandava from ribeirão da Batalha, farm Batalha (Pedro Quaresma), rio Paranaíba, Paracatu, Minas Gerais State, Brazil, LIRP 3239. Also known from tributaries of the upper rio Paraná basin, in the states of Mato Grosso do Sul, Goiás, Minas Gerais, and São Paulo (Ref. 128907). - 
Characidae Odontostilbe fugitiva Cope, 1870 Fr native    4.40 cm TL male/unsexed  Known from the Amazon River basin (Ref. 37055) and Machado river basin (Ref. 97589). - 
Characidae Odontostilbe microcephala Eigenmann, 1907 Fr native    4.60 cm SL male/unsexed ;5.20 cm SL female   - 
Characidae Odontostilbe nareuda Bührnheim & Malabarba, 2006 Fr native    3.79 cm SL male/unsexed  Known from the Madeira and Purus river basins (Ref. 57085). - 
Characidae Odontostilbe paraguayensis Eigenmann & Kennedy, 1903 Fr native    4.00 cm SL male/unsexed    - 
Characidae Odontostilbe parecis Bührnheim & Malabarba, 2006 Fr native   3.90 cm SL male/unsexed ;4.16 cm SL female  Known from rio Galera, rio Novo, upper rio Guaporé basin; also found in the Rio Madeira basin (Ref. 57085). - 
Characidae Odontostilbe pequira (Steindachner, 1882) Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)   5.60 cm SL male/unsexed    + 
Characidae Odontostilbe stenodon (Eigenmann, 1915) Fr native    3.30 cm SL male/unsexed  Known from the Paraná River basin (Ref. 48602). Type locality, Bebedouro, near Rio Grande and Rio Paraná (Ref. 46206). - 
Characidae Odontostilbe weitzmani Chuctaya, Bührnheim & Malabarba, 2018 Fr native   4.39 cm SL male/unsexed ;5.08 cm SL female  Type locality of Odontostilbe weitzmani from Lapa stream near the mouth and along the seawall of rock and the bridge of the road of Itirapina, São Paulo State, Brazil, MZUSP 121648. Also known from the tributaries of the upper rio Paraná, in the states of Goiás, Mato Grosso do Sul, Minas Gerais, and São Paulo (Ref. 128907). - 
Characidae Odontostoechus lethostigmus Gomes, 1947 Fr native    6.65 cm SL male/unsexed  Known from Maquiné, Tres Forquilhas and Mapituba River basins in southern Brazil. - 
Characidae Oligobrycon microstomus Eigenmann, 1915 Fr native    3.90 cm TL male/unsexed  Known from Rio Paraiba. - 
Carangidae Oligoplites palometa (Cuvier, 1832) Fr, Br, M native  Guaivira (Portuguese), Gaivira (Portuguese), Guaibira (Portuguese), Salteira (Portuguese), Tibiro (Portuguese), Tibiro amarelo (Portuguese), Tibiro-de-couro (Portuguese), Timbiro (Portuguese)  49.70 cm TL male/unsexed  Located at the southernmost tip of the Bombinhas peninsula, southern Brazil (Ref. 55758). + 
Characidae Oligosarcus acutirostris Menezes, 1987 Fr native    16.00 cm SL male/unsexed  Museum: Rio Itapemirim, Fazenda Boa Esperança, near Pacotuba and Coutinho, MZUSP 37525 (holotype of O. acutirostris, 10.4 cm SL, male) (Ref. 27925). - 
Characidae Oligosarcus argenteus Günther, 1864 Fr native  Lambari-bocarra (Portuguese)   10.50 cm SL male/unsexed  Found in the Doce and Das Velhas River basins (Ref. 38376). + 
Characidae Oligosarcus brevioris Menezes, 1987 Fr native  Peixe-cachorro (Portuguese), Saicanga (Portuguese)  28.00 cm TL male/unsexed  Known from the Uruguay River (Ref. 79585). Museum: Arroio Cachoeirinha, bacia do Rio Pelotas, Município Vacaria, RS, MZUSP 37508 (holotype of O. brevioris, 12.5 cm SL, female) (Ref. 27925). + 
Characidae Oligosarcus hepsetus (Cuvier, 1829) Fr, Br native  Tambicu (Portuguese), Saicanga (Portuguese), Tajibucu (Portuguese)   32.00 cm TL male/unsexed  Occurs in Betari River basin, Southeastern Brazil (Ref. 38979). Two Sigmodontinae were found in the stomachs of two individuals in different rivers located in the southern Brazilian Atlantic Rain Forest, in March and November 2010. These were the first records of this species feeding on mammals. + 
Characidae Oligosarcus jacuiensis Menezes & Ribeiro, 2010 Fr native   18.80 cm SL male/unsexed ;20.50 cm SL female  Known from the Jacuí and Uruguay River basins in Rio Grande do Sul (Ref. 85166). - 
Characidae Oligosarcus jenynsii (Günther, 1864) Fr, Fi native  Tambica (Portuguese), Branca (Portuguese), Lambari-bocarra (Portuguese), Peixe-cachorro (Portuguese), Saicanga (Portuguese), Tambicu (Portuguese)   31.00 cm TL male/unsexed  Recorded from the Patos lagoon (Ref. 58359) and the Uruguay River (Ref. 79585). + 
Characidae Oligosarcus longirostris Menezes & Géry, 1983 Fr native   22.50 cm SL male/unsexed ;29.50 cm SL female 9.52 Museum: Rio Iguaçu (Paraná basin) at Porto Lupion, State of Paraná, MZUSP 25481 (holotype of O. longirostris, 19 cm SL, female) (Ref. 27925). - 
Characidae Oligosarcus macrolepis (Steindachner, 1877) Fr native  Tambicu (Portuguese)   7.70 cm SL male/unsexed  Found in the Jequitinhonha River basin (Ref. 38376). - 
Characidae Oligosarcus oligolepis (Steindachner, 1867) Fr native  Tambicu (Portuguese)   26.20 cm SL male/unsexed    - 
Characidae Oligosarcus paranensis Menezes & Géry, 1983 Fr native  Tambicu (Portuguese)   20.50 cm SL male/unsexed ;16.00 cm SL female  Museum: Represa de Salesópolis (Tietê R. system), State of Sao Paulo, MZUSP 25721 (holotype of O. paranensis, 14.4 cm SL, female) (Ref. 27925). + 
Characidae Oligosarcus perdido Ribeiro, Cavallaro & Froehlich, 2007 Fr native   9.78 cm SL male/unsexed  Found only in the Rio Perdido, a tributary of Rio Apa, in the upper Paraguai basin and one of its tributaries, the Seputá stream (Ref. 72405). - 
Characidae Oligosarcus pintoi Amaral Campos, 1945 Fr native  Lambari (Portuguese), Sarda (Portuguese)   8.80 cm SL male/unsexed  Museum: Rio Mogi Guaçu, Sao Paulo State, MZUSP 3488 (Ref. 27925). Occurs in the Pardo River, upper Paraná River basin, southeastern Brazil (Ref. 27745). + 
Characidae Oligosarcus planaltinae Menezes & Géry, 1983 Fr native    9.90 cm SL male/unsexed ;7.90 cm SL female  Museum: Córrego Planaltina, tributary of Rio Sao Bartolomeu, Rio Paraná system, near Brasìlia, Goiás, MZUSP 25718 (holotype of O. planaltinae, 7.9 cm SL) (Ref. 27925). - 
Characidae Oligosarcus robustus Menezes, 1969 Fr native  Tambicu (Portuguese), Branca (Portuguese), Peixe cachorro (Portuguese), Tambica (Portuguese)  31.30 cm TL male/unsexed  Recorded from the Patos lagoon (Ref. 58359). Museum: Rio Caí in Montenegro, Rio Grande do Sul, Rio Guaíba basin, DZSP 4917 (holotype of O. robustus, 22 cm SL) (Ref. 27925). + 
Characidae Oligosarcus solitarius Menezes, 1987 Fr endemic    16.20 cm SL male/unsexed ;13.10 cm SL female  Museum: Lagoa Carioca, Vale do Rio Doce, Minas Gerias, MZUSP 37377 (holotype of O. solitarius, 13.1 cm SL, female) (Ref. 27925). Regarded as threatened in the state of Minas Gerais (Ref. 26603). - 
Characidae Oligosarcus varii Menezes & Ribeiro, 2015 Fr native   19.70 cm SL male/unsexed  Known only from its type locality, the rio Jacuí basin in Rio Grande do Sul. Could be classified as Least Concern (LC) based on IUCN classification as no threats were noticed (Ref. 104692). - 
Salmonidae Oncorhynchus mykiss (Walbaum, 1792) Fr, Fi, Aq introduced   122 cm TL male/unsexed   + 
Rivulidae Ophthalmolebias ilheusensis (Costa & Lima, 2010) Fr native    Found in an isolated coastal basin near Ilhéus, Bahia State, northeastern Brazil (Ref. 85562). - 
Cichlidae Oreochromis aureus (Steindachner, 1864) Fr, Br introduced   45.70 cm TL male/unsexed   + 
Cichlidae Oreochromis mossambicus (Peters, 1852) Fr, Br introduced   39.00 cm SL male/unsexed  Also Ref. 13364. + 
Cichlidae Oreochromis niloticus (Linnaeus, 1758) Fr, Br introduced  Tilápia-do-nilo (Portuguese), Tilápia (Portuguese)   60.00 cm SL male/unsexed  Found in the Uruguay River (Ref. 79585). Widely introduced for aquaculture, with many existing strains (Ref. 92328). + 
Characidae Orthospinus franciscensis (Eigenmann, 1914) Fr native  Piaba (Portuguese)  7.40 cm SL male/unsexed  Found in the São Francisco River basin (Ref. 36891). Type locality: Lagoas of Rio Grande at Barreiras, Rio Sao Francisco system, Bahia (Ref. 26282). - 
Apteronotidae Orthosternarchus tamandua (Boulenger, 1898) Fr native    44.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). - 
Doradidae Ossancora asterophysa Birindelli & Sabaj Pérez, 2011 Fr native   16.80 cm TL male/unsexed  Known from the Amazonas basin (Ref. 92411). Also recorded from upper Guaporé, Madeira drainage (Ref. 92411). - 
Doradidae Ossancora eigenmanni (Boulenger, 1895) Fr native  Rique-rique (Portuguese)   15.20 cm SL male/unsexed  Known from Descalvados, Mato Grosso (Ref. 6868). + 
Doradidae Ossancora fimbriata (Kner, 1855) Fr native    10.00 cm SL male/unsexed    - 
Doradidae Ossancora punctata (Kner, 1855) Fr native    11.30 cm SL male/unsexed    + 
Serrasalmidae Ossubtus xinguense Jégu, 1992 Fr native  Pacu (Portuguese)   25.00 cm TL male/unsexed  Known from the Xingu River basin (Ref. 39031). + 
Osteoglossidae Osteoglossum bicirrhosum (Cuvier, 1829) Fr, Fi, Or native  Sulamba (Portuguese), Arauaná (Portuguese), Arowana (Portuguese), Aruaná (Portuguese), Aruanã (Portuguese), Baiano (Portuguese), Carapaná (Portuguese), Macaco d'água (Portuguese)   90.00 cm TL male/unsexed  Present in the Oyapock River which forms the border between Brazil and French Guiana (Ref. 12225). Exported for the aquarium trade, especialy from the Rio Negro area (Ref. 27548) which is an illegal activity in Brazil (Ref. 102836). + 
Osteoglossidae Osteoglossum ferreirai Kanazawa, 1966 Fr endemic  Aruanã (Portuguese)  90.00 cm TL male/unsexed  Known from the Negro River basin (Ref. 50892). + 
Loricariidae Otocinclus affinis Steindachner, 1877 Fr native  Cascudinho (Portuguese), Limpa folhas (Portuguese), Limpa vidro (Portuguese)   5.00 cm SL male/unsexed  Also Ref. 7020. + 
Loricariidae Otocinclus arnoldi Regan, 1909 Fr native   4.78 cm SL male/unsexed  Known from the rio Uruguai drainage (Ref. 86395). - 
Loricariidae Otocinclus bororo Schaefer, 1997 Fr native   3.10 cm SL male/unsexed  Known from the upper Paraguay River basin (Ref. 36885). Type locality: Barra do Bugres, stream crossing road between Barra do Bugres and Cáceres, ca. 15°20'S, 57°12'W, Mato Grosso, Brazil (Ref. 26282). + 
Loricariidae Otocinclus caxarari Schaefer, 1997 Fr native    2.60 cm SL male/unsexed  Found in the upper Madeira River basin (Ref. 36885). Type locality: Between Guajara-Mirim and Mato Grosso, ca. 10°48'S, 65°23'W, Rio Solimoes/Madeira/Guaporé basin, Brazil/Bolivia border (Ref. 26282). - 
Loricariidae Otocinclus flexilis Cope, 1894 Fr native   6.80 cm TL male/unsexed  Known only from the laguna dos Patos drainage basin in Rio Grande do Sul (Ref. 86395). Type locality: Rio Grande do Sul (Ref. 6868). + 
Loricariidae Otocinclus hasemani Steindachner, 1915 Fr native    2.70 cm SL male/unsexed  Found in Tocantins and Parnaíba River basins (Ref. 36885). Type locality: Rio Parnaiba basin, Engenhao de Agua, ca. 4°52'S, 43°10'W, Maranhao State, Brazil (Ref. 26282). - 
Loricariidae Otocinclus hoppei Miranda Ribeiro, 1939 Fr native    3.30 cm SL male/unsexed  Found in the Amazon (Ref. 36885) and Machado River basin (Ref. 97589). Type locality: Belem, Para, northern Brazil (Ref. 6868). + 
Loricariidae Otocinclus juruenae Ribeiro & Lehmann A., 2016 Fr native   3.30 cm SL male/unsexed  Known only from Rio Juruena, Tapajos basin in central Brazil (Ref. 110382). - 
Loricariidae Otocinclus mangaba Lehmann A., Mayer & Reis, 2010 Fr native   2.82 cm SL male/unsexed  Known from the two creeks of the Rio Madeira drainage, the Igarapé do Vinte e Dois and the Igarapé do Doze, on the Transamazônica road, near Humaitá (Ref. 86269). - 
Loricariidae Otocinclus mura Schaefer, 1997 Fr native    3.60 cm SL male/unsexed  Found in the upper Amazon River basin (Ref. 36885). Type locality: Rio Sanabani, munícìpio de Silves, ca. 2°51'40"S, 58°15'40:W, rio Solimoes/Sanabani/Lago Canaçari basin, Brazil (Ref. 26282). - 
Loricariidae Otocinclus tapirape Britto & Moreira, 2002 Fr native   2.36 cm SL male/unsexed  Recorded from the upper and middle Rio Araguaia system (Ref. 46820). - 
Loricariidae Otocinclus vestitus Cope, 1872 Fr native    3.20 cm SL male/unsexed   + 
Loricariidae Otocinclus vittatus Regan, 1904 Fr native  Cascudinho limpa vidros (Portuguese), Limpa vidro (Portuguese)   3.30 cm TL male/unsexed  Found in the Purus and Acre River basins (Ref. 97592). Type locality: Descalvados, Rio Paraguay system, Mato Grosso, Brazil (Ref. 26282). + 
Loricariidae Otocinclus xakriaba Schaefer, 1997 Fr native  Cascudo (Portuguese)  3.10 cm SL male/unsexed  Known from the São Francisco River basin (Ref. 36885). Type locality: Rio Pau de Colher, on road between Guanambi and Mutas, 14°12'48"S, 42°49'29"W, Rio Sao Francisco basin, Bahia, Brazil (Ref. 26282). - 
Loricariidae Otothyris juquiae Garavello, Britski & Schaefer, 1998 Fr endemic   3.15 cm SL male/unsexed  Known from the tributaries of the Ribeira de Iguape river basin, Sao Paulo State. - 
Loricariidae Otothyris lophophanes (Eigenmann & Eigenmann, 1889) Fr endemic    2.82 cm SL male/unsexed  Known from the coastal streams of Rio de Janeiro State. + 
Loricariidae Otothyris rostrata Garavello, Britski & Schaefer, 1998 Fr native  Cascudinho (Portuguese)  3.10 cm SL male/unsexed  Known from the rivers of Santa Catarina and Rio Grande do Sul States. - 
Loricariidae Otothyris travassosi Garavello, Britski & Schaefer, 1998 Fr native    3.20 cm SL male/unsexed  Known from ther ivers of the Atlantic coast of Espirito Santo State to southern Bahia State. - 
Loricariidae Otothyropsis alicula Lippert, Calegari & Reis, 2014 Fr native   3.60 cm SL male/unsexed  Known from the Rio Santo Antônio basin, a tributary to Rio Sapucaí, itself a tributary to the upper Rio Grande, Rio Paraná basin (Ref. 96503). - 
Loricariidae Otothyropsis biamnicus Calegari, Lehmann A. & Reis, 2013 Fr native   3.99 cm SL male/unsexed  Known from the tributaries to rio Iguaçu, in Santa Catarina and Paraná States, and to the rio Tibagi, Paraná State, both in rio Paraná basin (Ref. 93039). - 
Loricariidae Otothyropsis marapoama Ribeiro, Carvalho & Melo, 2005 Fr native   3.63 cm SL male/unsexed  Known from rio Tietê, a river from the upper rio Paraná basin in southeastern Brazil (Ref. 56895). + 
Loricariidae Otothyropsis polyodon Calegari, Lehmann A. & Reis, 2013 Fr native   3.73 cm SL male/unsexed  Known from the tributaries to the rio Verde, a tributary to the upper rio Paraná basin in Mato Grosso do Sul (Ref. 93039). - 
Characidae Oxybrycon parvulus Géry, 1964 Fr native    2.09 cm SL male/unsexed   + 
Doradidae Oxydoras kneri Bleeker, 1862 Fr native  Focinho de porco (Portuguese), Armado cancho (Spanish), Abotoado (Portuguese), Armado (Portuguese), Armao (Portuguese), Armão (Portuguese), Armau (Portuguese), Bacu (Portuguese), Botoado (Portuguese), Cancho (Portuguese), Cari (Portuguese), Cuiú cuiú (Portuguese), Cuiucuiu (Portuguese), Cuju cuju (Portuguese), Cujuba (Portuguese), Cuyu cuyu (Portuguese), Cuyu cuyu pixuma (Portuguese), Cuyu cuyu prêto (Portuguese), Focinho-de-porco (Portuguese), Peixe de manilha (Portuguese), Tuiú (Portuguese), Vacu (Portuguese)   70.00 cm TL male/unsexed  Found in Paraná River (Ref. 37054). + 
Doradidae Oxydoras niger (Valenciennes, 1821) Fr, Fi native  Abotoado (Portuguese), Bacu (Portuguese), Cari (Portuguese), Cuiú cuiú (Portuguese), Cuiú cuiú boca de bezerro (Portuguese), Cuiú cuiú branco (Portuguese), Cuiucuiu (Portuguese), Cuju cuju (Portuguese), Cujuba (Portuguese), Cuyu cuyu (Portuguese), Focinho de porco (Portuguese), Peixe carneiro (Portuguese), Tuiú (Portuguese), Vacu (Portuguese), Cuiu-cuiu (Not specified), Cuyú-cuyú (Not specified), Toro (Not specified)   100.00 cm SL male/unsexed  Also Ref. 37054. + 
Loricariidae Oxyropsis acutirostris Miranda Ribeiro, 1951 Fr native   4.40 cm SL male/unsexed  Type locality: Rio Taquié, tributary of the Rio Negro, Amazonas, Paricachoeira. Also Ref. 6868. + 
Loricariidae Oxyropsis carinata (Steindachner, 1879) Fr native   7.60 cm SL male/unsexed  Known from the Amazon River (Ref. 36885). - 
Loricariidae Oxyropsis wrightiana Eigenmann & Eigenmann, 1889 Fr native    5.60 cm SL male/unsexed  Type locality: Lago Janauari (Lake Hyanuary) , Amazonas State (Ref. 43109). Ref. 6868. - 
Sciaenidae Pachypops fourcroi (Lacepède, 1802) Fr, Fi native  Pescada-cabeça-dura (Portuguese), Corvina (Portuguese), Curvina (Portuguese), Pescada (Portuguese), Pescadinha (Portuguese), Ronca (Portuguese)   25.00 cm TL male/unsexed    + 
Sciaenidae Pachypops pigmaeus Casatti, 2002 Fr native    5.60 cm SL male/unsexed  Known from the Branco and Madeira River drainages of the Amazon River basin (Ref. 36888). Type locality, Jamarizinho, Rio Machado, Rondônia, MZUSP 34108 (holotype of Pachypops pigmaeus) (Ref. 36888). + 
Sciaenidae Pachypops trifilis (Müller & Troschel, 1849) Fr, Fi native  Curvina (Portuguese), Pescada (Portuguese)   18.90 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36888). Found in fish markets in Santarém (Ref. 12202). + 
Sciaenidae Pachyurus adspersus Steindachner, 1879 Fr endemic  Corvina (Portuguese), Pescada (Portuguese)   26.40 cm SL male/unsexed  Known from the Atlantic versant rivers of Brazil, including Mucuri, Doce, and Paraíba do Sul River basins (Ref. 36888). Type locality, Rio Santo Antonio, Estado de Minas Gerais, (holotype of Pachyurus adspersus; lectotype NMW 31450 (Ref. 36888, 56787). Also Ref. 4537. + 
Sciaenidae Pachyurus bonariensis Steindachner, 1879 Fr native  Corvina (Portuguese), Pescada (Portuguese)   25.00 cm SL male/unsexed  Found in the Uruguay River (Ref. 79585). + 
Sciaenidae Pachyurus calhamazon Casatti, 2001 Fr native  Corvina (Portuguese), Pescada (Portuguese)  8.10 cm SL male/unsexed  Known from the Branco River (Ref. 36888). Type locality, Rio Branco, Estado de Roraima, MZUSP 66684 (holotype of Pachyurus calhamazon) (Ref. 36888). + 
Sciaenidae Pachyurus francisci (Cuvier, 1830) Fr endemic  Corvina (Portuguese), Corvina de água doce (Portuguese), Curvina (Portuguese), Pescada (Portuguese), Pescada corvina do São Francisco (Portuguese), Sofia (Portuguese)  29.70 cm SL male/unsexed  Known from the Sao Francisco River basin (Ref. 36888). Type locality, rivière de Sainte-Françoise, MNHN A.5600 (holotype of Pachyurus francisci, dry specimen) (Ref. 36888). Also Ref. 4537. + 
Sciaenidae Pachyurus gabrielensis Casatti, 2001 Fr native  Corvina (Portuguese), Pescada (Portuguese)  14.60 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36888). Type locality, Cachoeira São Gabriel, rio Negro, Estado do Amazonas, MZUSP A.5600 (holotype of Pachyurus gabrielensis, dry specimen) (Ref. 36888). + 
Sciaenidae Pachyurus junki Soares & Casatti, 2000 Fr endemic  Corvina (Portuguese), Pescada (Portuguese)   35.50 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36888). Type locality, Rio Solimões, Coari, Estado do Amazonas, INPA 619 (holotype of Pachyurus junki) (Ref, 36888). + 
Sciaenidae Pachyurus paucirastrus Aguilera, 1983 Fr endemic  Corvina (Portuguese), Pescada (Portuguese)   14.80 cm SL male/unsexed  Known from the Tocantins River basin (Ref. 36888). Type locality, Rio Tocantins, Capuerana, MNRJ 11176 (holotype of Pachyurus paucirastrus) (Ref. 36888). + 
Sciaenidae Pachyurus schomburgkii Günther, 1860 Fr native  Corvina (Portuguese), Pescada (Portuguese), Pescada pintada (Portuguese), Pescadinha (Portuguese)  28.50 cm SL male/unsexed ;28.90 cm SL female  Known from the Amazon River basin (Ref. 36888). Type locality, Rio Capin [Pará] and Caripe Pará, BMNH 49.11.8-22 (holotype of Pachyurus schomburgkii) (Ref. 36888). Also Ref. 4537. + 
Sciaenidae Pachyurus squamipennis Agassiz, 1831 Fr, Br, M endemic  Corvina-preta (Portuguese), Corvina (Portuguese), Corvina-da-água-doce (Portuguese), Pescada (Portuguese), Pescada-corvina-do São-Francisco (Portuguese), Sofia (Portuguese)   29.10 cm SL male/unsexed  Known from the São Francisco River basin (Ref. 36888). + 
Poeciliidae Pamphorichthys araguaiensis Costa, 1991 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  2.45 cm SL male/unsexed  Known from the Araguaia-Tocantins and Xingu River basins (Ref. 50894). Type locality: Araguaia basin, Goiás. - 
Poeciliidae Pamphorichthys hasemani (Henn, 1916) Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)   2.50 cm TL male/unsexed ;2.50 cm female  Found in the Pantanal Brasileiro (upper portions of drainage of the Paraguay River in Mato Grosso (Ref. 50894). - 
Poeciliidae Pamphorichthys hollandi (Henn, 1916) Fr endemic  Barrigudinho (Portuguese), Guaru (Portuguese), Lebiste (Portuguese)  2.50 cm TL male/unsexed ;4.50 cm female  Known from the Rio Sao Francisco basin, Rio Itapicuru and the flowing waters near Santos. + 
Poeciliidae Pamphorichthys minor (Garman, 1895) Fr endemic  Barrigudinho (Portuguese), Guaru (Portuguese)  1.70 cm SL male/unsexed  Known from the Amazon basin in Villa Bella, Mato Grosso. - 
Poeciliidae Pamphorichthys pertapeh Figueiredo, 2008 Fr native   1.72 cm SL male/unsexed   - 
Poeciliidae Pamphorichthys scalpridens (Garman, 1895) Fr endemic  Barrigudinho (Portuguese), Guaru (Portuguese)  2.00 cm TL male/unsexed ;4.00 cm female  Known from the Amazon basin, Santarem, Obidos, Rio Tapajos, Ro Trombetas, Para, Villa Bella and Mato Grosso. - 
Loricariidae Panaqolus claustellifer Tan, Souza & Armbruster, 2016 Fr native   6.16 cm SL male/unsexed  Known from the Amazon River drainage (Ref. 109759). - 
Loricariidae Panaqolus nix Cramer & Rapp Py-Daniel, 2015 Fr native   11.22 cm SL male/unsexed  Known from the middle Madeira and Mamoré rivers. Habitats of this species have been severely altered by the construction of hydroelectric power plants, destroying the former Santo Antônio and Jirau rapids and transforming more than 200 km of the rio Madeira, enlarging the riverbed and reducing the current (Ref. 104707). Status of threat: should be classifiedas Least Concern (LC) (Ref. 104707). - 
Loricariidae Panaqolus purusiensis (La Monte, 1935) Fr native   13.04 cm SL male/unsexed  Known from Macauá River basin in the upper Purus drainage (Ref. 36713). Also Ref. 6868. - 
Loricariidae Panaque armbrusteri Lujan, Hidalgo & Stewart, 2010 Fr native   43.00 cm TL male/unsexed  Widely distributed in the Tapajós River and its tributaries (Ref. 85845). + 
Loricariidae Panaque bathyphilus Lujan & Chamon, 2008 Fr native   7.35 cm SL male/unsexed   + 
Loricariidae Panaque nigrolineatus (Peters, 1877) Fr native  Acarí (Portuguese), Acarí da pedra (Portuguese), Acarí tamanco (Portuguese), Acari-da-pedra (Portuguese)   43.00 cm SL male/unsexed    + 
Loricariidae Panaque schaeferi Lujan, Hidalgo & Stewart, 2010 Fr native     Widely distributed in the main-channel habitats of the upper Amazon (Solimões) River basin (Ref. 85845). + 
Trichomycteridae Paracanthopoma parva Giltay, 1935 Fr native    2.70 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39970). Type locality: Upper Rio Catrymany, affluent of Rio Branco, Roraima terr., Brazil (Ref. 26282, 6868). - 
Trichomycteridae Paracanthopoma saci Dagosta & de Pinna, 2021 Fr native   2.18 cm SL male/unsexed  Type locality of Paracanthopoma saci, Mato Grosso do Sul, Alcinópolis, Rio Taquarizinho (tributary to Rio Taquari, Rio Paraguay drainage) (Ref. 124573). - 
Characidae Paracheirodon axelrodi (Schultz, 1956) Fr, Or native  Tetra cardinal (Portuguese) fairly common (chances are about 50%) 2.51 cm SL male/unsexed   + 
Characidae Paracheirodon innesi (Myers, 1936) Fr native  Bandeirinha (Portuguese), Cardinal (Portuguese), Tetra neon (Portuguese)  2.22 cm SL male/unsexed   + 
Characidae Paracheirodon simulans (Géry, 1963) Fr native    2.02 cm SL male/unsexed  Recorded from the Rio Negro (Ref. 598). + 
Cichlidae Parachromis motaguensis (Günther, 1867) Fr, Br misidentification   30.00 cm TL male/unsexed  Ref. 7335 gives Guatemala and Honduras as native range, whereas Ref. 1739 (probably in error) gives "Amazon". Occurrence in the country is not confirmed (Ref. 36377). + 
Characidae Paragoniates alburnus Steindachner, 1876 Fr native    6.00 cm TL male/unsexed  Found in the Amazon (Ref. 38376) and Acre River basins (Ref. 97592). + 
Loricariidae Paralithoxus jariensis (Silva, Covain, Oliveira & Roxo, 2017) Fr native   6.06 cm SL male/unsexed  Found only in rio Jari and small tributaries in the municipality of Almerim and Laranjal do Jari, Amapá State (Ref. 118148). - 
Loricariidae Paralithoxus raso (Silva, Covain, Oliveira & Roxo, 2017) Fr native   4.64 cm SL male/unsexed  Known only from igarapé Raso in Municipality of Amapá, Amapá State (Ref. 118148). - 
Loricariidae Paraloricaria commersonoides (Devincenzi, 1943) Fr questionable   37.00 cm male/unsexed   - 
Loricariidae Paraloricaria vetula (Valenciennes, 1835) Fr native  Cascudo-viola (Portuguese), Viola (Portuguese)  55.40 cm TL male/unsexed  Found in the La Plata River (Ref. 36389). Reported from the Uruguay River (Ref. 79585). + 
Loricariidae Parancistrus aurantiacus (Castelnau, 1855) Fr native  Acari (Portuguese)  19.30 cm SL male/unsexed  Known from Tocantins and Xingu Rivers (Ref. 36713). + 
Loricariidae Parancistrus nudiventris Rapp Py-Daniel & Zuanon, 2005 Fr native   22.00 cm TL male/unsexed  Known from rio Xingu (Ref. 56911). + 
Pimelodidae Parapimelodus nigribarbis (Boulenger, 1889) Fr endemic  Mandi (Portuguese)  19.80 cm TL male/unsexed  Restricted to the laguna dos Patos system (Ref. 58359), Rio Grande do Sul (Ref. 30579). + 
Pimelodidae Parapimelodus valenciennis (Lütken, 1874) Fr native  Mandi (Portuguese), Bagre (Portuguese), Mandí (Portuguese)  24.00 cm SL male/unsexed  Known from the Paraná River basin (Ref. 36506). Reported from the Uruguay River (Ref. 79585). + 
Apteronotidae Parapteronotus hasemani (Ellis, 1913) Fr native    38.10 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). - 
Trichomycteridae Parastegophilus maculatus (Steindachner, 1879) Fr native    6.00 cm SL male/unsexed    - 
Trichomycteridae Parastegophilus paulensis (Miranda Ribeiro, 1918) Fr native   5.40 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 39970). + 
Potamotrygonidae Paratrygon aiereba (Müller & Henle, 1841) Fr native  Arraia (Portuguese), Aiereba (Portuguese), Aramaçá (Portuguese), Arraia branca (Portuguese), Arraia maça (Portuguese), Arraia preta (Portuguese), Raia (Portuguese), Rodeirão (Portuguese), Rodeiro (Portuguese)   80.00 cm WD male/unsexed ;78.00 cm WD female  Occurs in the Amazon basin. + 
Trichomycteridae Paravandellia oxyptera Miranda Ribeiro, 1912 Fr native  Candiru (Portuguese)   2.80 cm NG male/unsexed  Known from the Uruguay River (Ref. 79585). Type locality: Caceres, Río Paraguay, Mato Grosso, Brazil (Ref. 26282). Also Ref. 6868, 39970. + 
Characidae Parecbasis cyclolepis Eigenmann, 1914 Fr native    8.00 cm SL male/unsexed    - 
Trichomycteridae Pareiodon microps Kner, 1855 Fr native     Known from the Amazon River basin (Ref. 39970). Type locality: Araguay Borba, Rio Madeira, about 4 days from Amazon mouth (Ref. 26282, 6868). + 
Loricariidae Pareiorhaphis azygolechis (Pereira & Reis, 2002) Fr native  scarce (very unlikely) 11.66 cm SL male/unsexed  Known from rio São João drainage only, in the states of Santa Catarina and Paraná. Type locality, rio Araraquara, Guaratuba, Paraná (Ref. 42856). - 
Loricariidae Pareiorhaphis bahianus (Gosline, 1947) Fr native    12.00 cm TL male/unsexed  Occurs in small coastal drainages near Ilhéus, between the basins of rio Pardo and rio Contas, in southern Bahia. Collected from Fazenda Almada; rio Branco (tributary of rio Una); creek tributary to rio Almada at Duas Barras (Ref. 42856). Type locality: Fazenda Almada, Ilhus (Ilhéus), Bahia, Brazil (Ref. 26282, 6868). - 
Loricariidae Pareiorhaphis cameroni (Steindachner, 1907) Fr native  Cascudo (Portuguese)  17.00 cm TL male/unsexed  Known from the drainages of Cubataõ, Tubarao and Ararangua rivers, and all coastal streams of Santa Catarina (Ref. 42856). Type locality: Rio Cubatao in Santa Catharina at Theresopolis, Brazil (Ref. 26282). Also Ref. 6868, 32949, 36817, 50588. - 
Loricariidae Pareiorhaphis cerosus (Miranda Ribeiro, 1951) Fr native   11.01 cm SL male/unsexed   - 
Loricariidae Pareiorhaphis eurycephalus (Pereira & Reis, 2002) Fr native   6.28 cm SL male/unsexed  Known from the upper reaches of the rio Canoas in the highlands of southern Santa Catarina State (Ref. 42856). Type locality, creek tributary of rio Canoas E of vila São José, on road to serra do Corvo Branco, Urubici, Santa Catarina (Ref. 42856). - 
Loricariidae Pareiorhaphis garapia Pareira, Lehmann A., Schvambach & Reis, 2015 Fr native  scarce (very unlikely) 6.02 cm SL male/unsexed  Found only in a stretch of the Arroio Garapiá upstream from a major and well known waterfall in its lower course (Ref. 105131). Arroio Garapiá is a tributary to the Rio Forqueta, itself a tributary to the Rio Maquiné which empties in the Tramandaí Lagoon system in the coastal plains of Rio Grande do Sul. After extensive collection efforts from the Rio Maquiné drainage basin during the past several years, this species was never recorded from the main river itself or in other adjacent streams. The entire type series was obtained only at a private and well-preserved area. Since this species occurs in low abundance and very restricted area, the establishment of a Private Reserve of Natural Heritage-RPPN would be a good alternative for preserving this species (Ref. 105131). - 
Loricariidae Pareiorhaphis garbei (Ihering, 1911) Fr endemic  Cascudo (Portuguese)   14.00 cm TL male/unsexed  Found in the rivers of the southern versant of the serra dos Orgaos in Rio de Janeiro, rio Macae and rio Macacu (Ref. 42856). Type locality: Rio Macahé, Estado de Rio de Janeiro, Brazil (Ref. 26282, 6868). Also Ref. 32949. + 
Loricariidae Pareiorhaphis hypselurus (Pereira & Reis, 2002) Fr native    6.91 cm SL male/unsexed  Known from rio Maquiné and rio Três Forqilhas, in the coastal plains of NE Rio Grande do Sul; also in rio Mampituba and rio Araranguá, and in southern Santa Catarina. Type locality, rio Forqueta tributary to rio Maquiné, Rio Grande do Sul (Ref. 42856). + 
Loricariidae Pareiorhaphis hystrix (Pereira & Reis, 2002) Fr native   11.45 cm SL male/unsexed  Occurs in the headwater of the rio Pelotas, upper portions of the rio Uruguai, and in rio das Antas (rio Jacui drainage); apparently another disjunct population occurs in the rio Ijui and rio Piratinim, tributaries of Uruguai in western Rio Grande do Sul. Type locality, creek tributary of rio dos Touros, on road from Silveira to Rondinha, Bom Jesus, Rio Grande do Sul (Ref. 42856). - 
Loricariidae Pareiorhaphis lophia Pereira & Zanata, 2014 Fr native  Acari (Portuguese), Chupa-pedra (Portuguese)  8.21 cm SL male/unsexed  Known from the middle portion of the rio Paraguaçu and two tributaries of its upper portion (Ref. 95497). - 
Loricariidae Pareiorhaphis mucurina Pereira, Pessali & Reis, 2018 Fr native  abundant (always seen in some numbers) 9.72 cm SL male/unsexed  Type locality of Pareiorhaphis mucurina, Minas Gerais, Catuji, Preto River, Mucuri River basin (Ref. 119415). Conservation status: currently known from two localities separated by 2.5 river km in the Preto River, upper Mucuri River basin; it is relatively abundant. Despite the Extent of Occurrence (EOO) based on known localities is very narrow, it is estimated to occur widely in the upper portions of the Mucuri River basin with similar habitats. Threats include contamination by domestic sewage, Eucalyptus plantation, cattle ranching, and deforestation observed in the area, but no specific threats were detected. Thus, it should be categorized as Least Concern (LC) according to IUCN criteria (IUCN Standards and Petitions Subcommittee, 2017) (Ref. 119415). - 
Loricariidae Pareiorhaphis mutuca (Oliveira & Oyakawa, 1999) Fr native  Cascudo (Portuguese)   9.60 cm SL male/unsexed  Known only from the Mutuca creek, Rio das Velhas drainage in Minas Gerais, Brazil. Its range possibly includes all the headwates of Rio das Velhas (Ref. 32949). - 
Loricariidae Pareiorhaphis nasuta Pereira, Vieira & Reis, 2007 Fr endemic    9.47 cm SL male/unsexed  Known from three localities in the upper rio Doce basin in Minas Gerais: ribeirão Areia Branca, a tributary to the rio Matipó, and the two sites in the rio Matipó itself (Ref. 75793). - 
Loricariidae Pareiorhaphis nudulus (Reis & Pereira, 1999) Fr native    3.40 cm SL male/unsexed  Known from the rio Araranguá, rio Mapituba, rio Tres Forquilhas and rio Maquine in southern Santa Catarina and northeastern Rio Grande do Sul (Ref. 42856). Also Ref. 32858, 36817. + 
Loricariidae Pareiorhaphis parmula Pereira, 2005 Fr native    Known from the headwaters of rio Iguaçu basin (Ref. 56652). - 
Loricariidae Pareiorhaphis proskynita Pereira & Britto, 2012 Fr native   9.59 cm SL male/unsexed  Found in the upper portion of the Ribeirão Caraça, tributary to Rio Piracicaba. Collected above 1100 m and within the limits of the R.P.P.N. Santuário do Caraça, Catas Altas, Minas Gerais State (Ref. 91754). - 
Loricariidae Pareiorhaphis regani (Giltay, 1936) Fr native   12.11 cm SL male/unsexed  Found in rio Curicuriari and possibly in Jau, tributaries of rio Negro, in the Amazon basin (Ref. 42856). Type locality: Rio Curi Curiay, south of upper R. Negro, Amazonas, Brazil (Ref. 26282, 6868). - 
Loricariidae Pareiorhaphis ruschii Pereira, Lehmann A. & Reis, 2012 Fr native    8.47 cm SL male/unsexed  Type locality. Known from the upper reaches of the rio Piraquê-Açu and rio Reis Magos in Espírito Santo State (Ref. 91743). - 
Loricariidae Pareiorhaphis scutula Pereira, Vieira & Reis, 2010 Fr native   9.05 cm SL male/unsexed  Type locality, Minas Gerais, Nova Era, rio Doce drainage, córrego Prainha, tributary to rio Piracicaba, MCP 44046 (holotype of Pareiorhaphis scutula, 8.47 cm SL). Known from the córrego Prainha, a creek tributary to the rio Piracicaba in the upper reaches of the rio Doce drainage basin near Nova Era, Minas Gerais (Ref. 84022). - 
Loricariidae Pareiorhaphis splendens (Bizerril, 1995) Fr native   6.52 cm SL male/unsexed  Occurs in the coastal drainages of Santa Catarina (rio Cubatao N, rio Itajaí-Açu and rio Cubatao S) and Paraná (rio Nhundiaquara and rio Sao Joao). Also Ref. 36817. - 
Loricariidae Pareiorhaphis steindachneri (Miranda Ribeiro, 1918) Fr native  Cascudo (Portuguese)  14.30 cm SL male/unsexed  Occurs in the rio Cubatão, rio Itapocu, rio Itajaí-Açu in Santa Catarina State (Ref. 42856). Also Ref. 6868, 58032. - 
Loricariidae Pareiorhaphis stephanus (Oliveira & Oyakawa, 1999) Fr native   9.85 cm SL male/unsexed  Known from the headwaters of the rio Jequitinhonha in Minas Gerais and rio Sao Francisco in Itacarambi (Ref. 42856). Also Ref. 32949, 36817. - 
Loricariidae Pareiorhaphis stomias (Pereira & Reis, 2002) Fr native   5.18 cm SL male/unsexed  Known from the southern portion of Santa Catarina coastal region, in the drainages of rio Araranguá and rio Tubarão. Type locality, rio Mãe Luzia at Forquilha, Treviso, Santa Catarina (Ref. 42856). + 
Loricariidae Pareiorhaphis vestigipinnis (Pereira & Reis, 1992) Fr native   9.80 cm SL male/unsexed  Collected from the rio Uruguai drainage. Occurs in the headwaters of the rio Canoas and its tributaries in Santa Catarina (Ref. 42856). Type locality: Creek trib. of Rio Caveiras at Painel, ca. 27°55'S, 50°05'W, Lajes, Santa Catarina, Brazil (Ref. 26282). Also Ref. 32949, 36817. - 
Loricariidae Pareiorhina brachyrhyncha Chamon, Aranda & Buckup, 2005 Fr native   4.21 cm SL male/unsexed  Occurs in the stony piedmont tributaries of the left bank of Rio Paraiba do Sul in São Paulo, southeastern Brazil. - 
Loricariidae Pareiorhina carrancas Bockmann & Ribeiro, 2003 Fr native    4.12 cm SL male/unsexed  Known only from the córrego Debaixo da Serra, a small stream in the upper reaches of the rio Grande basin (Alto Paraná), in the piedmont of Serra de Carrancas, Carrancas, State of Minas Gerais (Ref. 52873). + 
Loricariidae Pareiorhina cepta Roxo, da Costa e Silva, Mehanna & Oliveira, 2012 Fr native   4.43 cm SL male/unsexed  Type locality. Known only from Córrego do Lavapés and Córrego Maria da Prata, which are two small headwater streams in the upper Rio São Francisco basin, near Serra da Canastra, Minas Gerais State (Ref. 92077). - 
Loricariidae Pareiorhina hyptiorhachis Silva, Roxo & Oliveira, 2013 Fr native   3.90 cm SL male/unsexed  Found in Rio Pomba and one of its tributaries, the Ribeirão Fernandes, in the municipality of Santa Barbara do Tugúrio, Minas Gerais State (Ref. 93835). - 
Loricariidae Pareiorhina pelicicei Azevedo-Santos & Roxo, 2015 Fr native   4.74 cm SL male/unsexed ;4.20 cm SL female  Type locality. Known only from córrego Tamborete, a small tributary of rio Grande (upper rio Paraná basin), municipality of Capitólio, Minas Gerais State (Ref. 100791). + 
Loricariidae Pareiorhina rosai Silva, Roxo & Oyakawa, 2016 Fr native   4.73 cm SL male/unsexed  Type locality of Pareiorhina rosai: Rio São Francisco basin, Minas Gerais (Ref. 107875). - 
Loricariidae Pareiorhina rudolphi (Miranda Ribeiro, 1911) Fr native   4.89 cm SL male/unsexed  Type locality: Piquete, State of Sao Paulo, Brazil (Ref. 26282, 6868). + 
Heptapteridae Pariolius armillatus Cope, 1872 Fr native   3.20 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36914). + 
Apteronotidae Pariosternarchus amazonensis Albert & Crampton, 2006 Fr native    15.20 cm SL male/unsexed  Type locality, Municipality of Alvarães, Mamirauá Lake System, Paraná Maiana, Amazonas, MCP 34916 (holotype of Pariosternarchus amazonensis, 12.1 cm SL). Also collected along the Rio Solimões frm near the confluence of the Rio Japurá to near the confluence of the Rio Madeira (Ref. 57730). - 
Parodontidae Parodon bifasciatus Eigenmann, 1912 Fr native  scarce (very unlikely) 9.80 cm SL male/unsexed  A very rare species recorded from Rio Branco (Ref. 598). - 
Parodontidae Parodon buckleyi Boulenger, 1887 Fr native    15.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38267). + 
Parodontidae Parodon hilarii Reinhardt, 1867 Fr native  Canivete (Portuguese)   13.67 cm SL male/unsexed  Known from São Francisco River basin (Ref. 38267). - 
Parodontidae Parodon moreirai Ingenito & Buckup, 2005 Fr native    11.78 cm SL male/unsexed  Headwater streams of the Rio Sapucaí drainage, a tributary of the Rio Grande basin, upper Paraná system. - 
Parodontidae Parodon nasus Kner, 1859 Fr native  Canivete (Portuguese), Duro-Duro (Portuguese), Tanchina (Portuguese)   12.70 cm SL male/unsexed 7.8 TL Found in the streams of the rio Machado Basin, Rondônia State (Ref. 97589). Recorded from Matto Grosso (Ref. 598). Type locality: Rio Cuiabá, Brazil (Ref. 33021). Also Ref. 38267, 51923. + 
Parodontidae Parodon pongoensis (Allen, 1942) Fr native   10.40 cm SL male/unsexed  Known from Amazon River tributaries (Ref. 38267). + 
Loricariidae Parotocinclus amazonensis Garavello, 1977 Fr native    2.45 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36885). Found in Ilha Sorubim, Rio Solimoes, Amazonas (Ref. 6868) - 
Loricariidae Parotocinclus arandai Sarmento-Soares, Lehmann A. & Martins-Pinheiro, 2009 Fr native    4.28 cm SL male/unsexed  Found in the middle and upper rio Jucuruçu and upper rio Buranhém, close to the border of southern Bahia and northeastern Minas Gerais States (Ref. 81204). - 
Loricariidae Parotocinclus aripuanensis Garavello, 1988 Fr native   2.09 cm SL male/unsexed  Known from Rio Aripuaña basin, Mato Grosso (Ref. 26706, 46237). - 
Loricariidae Parotocinclus bahiensis (Miranda Ribeiro, 1918) Fr native  Cascudinho (Portuguese)   3.12 cm SL male/unsexed  Found in Villa Nova, Bahia. + 
Loricariidae Parotocinclus bidentatus Gauger & Buckup, 2005 Fr native   3.79 cm SL male/unsexed  Known from the rio Paraíba do Sul basin (Ref. 56918). - 
Loricariidae Parotocinclus cearensis Garavello, 1977 Fr native   5.00 cm SL male/unsexed  Found in Cachoeira do Gusmao, Ipu, Ceara. - 
Loricariidae Parotocinclus cesarpintoi Miranda Ribeiro, 1939 Fr native    3.97 cm SL male/unsexed  Known from Rio Paraiba at Quebrangulo, Alagoas in northeastern Brazil. - 
Loricariidae Parotocinclus cristatus Garavello, 1977 Fr native    4.00 cm TL male/unsexed  Found in coastal rivers near Ilhéus, Bahia (Ref. 36885). Type locality: Fazenda Almada, Ilhéus, Bahia, Brazil (Ref. 6868, 26282). - 
Loricariidae Parotocinclus doceanus (Miranda Ribeiro, 1918) Fr native    4.38 cm SL male/unsexed  Found in the Doce River basin (Ref. 36885). Type locality: Rio Doce, Espiritu Santo, Brazil (Ref. 6868). - 
Loricariidae Parotocinclus fluminense Roxo, Melo, Silva & Oliveira, 2017 Fr native   3.08 cm SL male/unsexed  Type locality of Parotocinclus fluminense: Rio São João drainage, Rio de Janeiro (Ref. 117349). - 
Loricariidae Parotocinclus halbothi Lehmann A., Lazzarotto & Reis, 2014 Fr native   1.99 cm SL male/unsexed  Known from two streams in the rio Trombetas basin, a tributary to the rio Amazonas (Ref. 95582). - 
Loricariidae Parotocinclus haroldoi Garavello, 1988 Fr native    3.49 cm SL male/unsexed  Found in Piauí (Ref. 36885). - 
Loricariidae Parotocinclus jacksoni Ramos, Lustosa-Costa, Barros-Neto & Barbosa, 2021 Fr native   4.16 cm SL male/unsexed  Type locality of Parotocinclus jacksoni, Paraíba, Arara, Rio Fechado, tributary to Rio Mamanguape. Occurs in Rio Mamanguape basin with its headwaters and middle reaches running through the Caatinga (from wetter to drier) and its lower reaches through the Atlantic Forest. This area is presently altered by anthropic actions (Ref. 124638). - 
Loricariidae Parotocinclus jequi Lehmann A., Koech Braun, Pereira & Reis, 2013 Fr native   5.35 cm SL male/unsexed  Known from a headwater creek of the Rio Jequitinhonha in Serro, Minas Gerais (Ref. 94247). - 
Loricariidae Parotocinclus jimi Garavello, 1977 Fr native   4.00 cm TL male/unsexed  Type locality: Rio do Peixe, small tributary of Rio de Contas, Fazenda Pedra Branca, Itagiba, Bahia, Brazil (Ref. 6868). - 
Loricariidae Parotocinclus jumbo Britski & Garavello, 2002 Fr native   5.78 cm SL male/unsexed  Known from Paraiba do Norte and Piranhas rivers (Paraiba State), Canhotinho River (Pernambuco State), a tributary of the Mundau River, flowing near the city of Maceio (Alagoas State), and Salgado River, a tributary of the Jaguaribe River at Ico (Ceara State). + 
Loricariidae Parotocinclus longirostris Garavello, 1988 Fr native   2.65 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36885). - 
Loricariidae Parotocinclus maculicauda (Steindachner, 1877) Fr native    6.10 cm TL male/unsexed  Found in coastal rivers between Santa Catarina and Rio de Janeiro (Ref. 36885). Type locality: southeast Brazil (Ref. 6868). + 
Loricariidae Parotocinclus minutus Garavello, 1977 Fr native   3.28 cm SL male/unsexed  Type locality: Rio Vasa Barris, Canudos, Bahia, Brazil (Ref. 6868). - 
Loricariidae Parotocinclus muriaensis Gauger & Buckup, 2005 Fr native   3.05 cm SL male/unsexed  Known from rio Paraíba do Sul basin (Ref. 56918). - 
Loricariidae Parotocinclus planicauda Garavello & Britski, 2003 Fr endemic    4.27 cm SL male/unsexed  Found only in the Suaçui Pequeno River, a tributary of the Doce River, flowing near the city of Coroaci, Minas Gerais State (Ref. 57861). - 
Loricariidae Parotocinclus prata Ribeiro, Melo & Pereira, 2002 Fr native  Cascudo (Portuguese)  4.95 cm SL male/unsexed  Known from the upper reaches of the rio da Prata, a tributary of the rio Sao Francisco basin in Minas Gerais State. - 
Loricariidae Parotocinclus robustus Lehmann A. & Reis, 2012 Fr native   4.20 cm SL male/unsexed  Found in the three rivers belonging to the upper and middle Rio São Francico basin, the Rio das Velhas and Rio Jequitaí on the right margin and the Rio Paracatu on the left margin, suggesting that the species is widely distributed across the basin (Ref. 91034). - 
Loricariidae Parotocinclus seridoensis Ramos, Barris-Neto, Britski & Lima, 2013 Fr native   4.26 cm SL male/unsexed  Known from the upper rio Piranhas-Açu basin in northeastern Brazil (Ref. 94698). - 
Loricariidae Parotocinclus spilosoma (Fowler, 1941) Fr native   6.00 cm TL male/unsexed  Type locality: Campina Grande, Parahyba (Ref. 6868). + 
Loricariidae Parotocinclus spilurus (Fowler, 1941) Fr native   4.00 cm SL male/unsexed  Type locality: Rio Salgade, Ico, Ceara (Ref. 6868). - 
Loricariidae Peckoltia bachi (Boulenger, 1898) Fr native  Bode osoro (Portuguese)   14.00 cm TL male/unsexed  Found throughout the upper Amazon and its tributaries (Ref. 77026). Known from Juruá River basin (Ref. 36713). Also Ref. 6868. + 
Loricariidae Peckoltia braueri (Eigenmann, 1912) Fr native    10.30 cm SL male/unsexed  Known from Rio Negro drainage and the mainstem Rio Branco near Caracarai and the Rio Uraricoera drainage (Ref. 54521). + 
Loricariidae Peckoltia brevis (La Monte, 1935) Fr endemic  Bode cabra (Portuguese)   11.40 cm SL male/unsexed  Known from Purus (Ref. 36713) and Acre River basins (Ref. 97592). Also Ref. 6868. + 
Loricariidae Peckoltia compta De Oliveira, Zuanon, Rapp Py-Daniel & Rocha, 2010 Fr native   6.15 cm SL male/unsexed  Type locality, Pará, Itaituba, Pimental, rio Tapajós downstream from the confluence with rio Jamanxim, INPA 6865 (holotype of Peckoltia compta, 5.66 cm SL). Collected from two localities in rio Tapajós, near the village of Pimental, downstream from the confluence with rio Jamanxim, and in rio Jamanxim around ilha da Terra Preta (Ref. 84541). + 
Loricariidae Peckoltia ephippiata Armbruster, Werneke & Tan, 2015 Fr native   10.17 cm SL male/unsexed  Type locality of Peckoltia ephippiata, Rôndonia, Presidente Médici. rio Madeira dr., rio Leitão on highway BR-364, about 5 km N of Presidente Médici. Found only in Rio Leitão, rio Madeira drainage in Rôndonia (Ref. 99824). - 
Loricariidae Peckoltia greedoi Armbruster, Werneke & Tan, 2015 Fr native   7.80 cm SL male/unsexed  Type locality of Peckoltia greedoi, Pará, río Gurupi on BR 316 at border of Pará and Maranhão. Known only from rio Gurupi drainage in Pará (Ref. 99824). - 
Loricariidae Peckoltia lineola Armbruster, 2008 Fr native    9.69 cm SL male/unsexed   + 
Loricariidae Peckoltia multispinis (Holly, 1929) Fr, Or native   14.80 cm TL male/unsexed  Exported to North America as an aquarium fish (Ref. 4537). - 
Loricariidae Peckoltia oligospila (Günther, 1864) Fr endemic    15.00 cm TL male/unsexed  Known from the lower Amazon River basin (Ref. 36713). Also Ref. 6868. + 
Loricariidae Peckoltia vermiculata (Steindachner, 1908) Fr endemic   13.00 cm SL male/unsexed  Known from middle and lower Amazon River basin (Ref. 36713). Also Ref. 6868. - 
Loricariidae Peckoltia vittata (Steindachner, 1881) Fr native   15.00 cm TL male/unsexed  Known from middle and lower Amazon River basin (Ref. 36713). Also Ref. 6868, 77026. + 
Pristigasteridae Pellona castelnaeana Valenciennes, 1847 Fr, Br, Fi native  Apapa (Portuguese), Apapá (Portuguese), Apapa amarela (Portuguese), Apapá amarelo (Portuguese), Arenga (Portuguese), Arenque (Portuguese), Bode (Portuguese), Cagona (Portuguese), Dourada (Portuguese), Dourada de escama (Portuguese), Sarda (Portuguese), Sardinha branca (Portuguese), Sardinhão (Portuguese)   80.00 cm FL male/unsexed  Known from the Amazon River basin (Ref. 50591). Also Ref. 188. + 
Pristigasteridae Pellona flavipinnis (Valenciennes, 1837) Fr, Br, Fi native  Apaca branca (Portuguese), Apapá (Portuguese), Apapá branco (Portuguese), Sarda (Portuguese), Sardinha (Portuguese), Sardinha dourada (Portuguese), Sardinha grande (Portuguese), Sardinhão (Portuguese)   73.00 cm TL male/unsexed  Known from the Amazon River and from Río Tapajoz (Ref. 12225). Also Ref. 5217, 12202. + 
Sciaenidae Petilipinnis grunniens (Jardine & Schomburgk, 1843) Fr native  Pescada (Portuguese), Corvina (English)   27.90 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36888). - 
Characidae Petitella bleheri (Géry & Mahnert, 1986) Fr native    3.60 cm SL male/unsexed  Type locality of Hemigrammus bleheri, Middle Rio Negro basin (probably near Rio Jufaris), MZUSP 37369 (holotype, 3.6 cm SL) (Ref. 27925, 127081). Also Ref. 38376. + 
Characidae Petitella georgiae Géry & Boutière, 1964 Fr native    3.86 cm SL male/unsexed    + 
Characidae Petitella rhodostoma (Ahl, 1924) Fr native  Cara de sangue (Portuguese), Máscara vermelha (Portuguese), Rodóstomo (Portuguese), Tetra nariz vermelho (Portuguese)  5.00 cm TL male/unsexed  Recorded from the Amazon region (Ref. 598). + 
Anostomidae Petulanos intermedius (Winterbottom, 1980) Fr native   18.50 cm TL male/unsexed  Known from Xingu River basin (Ref. 36801). Type locality: Below the cataracts near Suya-Missu or Paranajuba, upper Rio Xingu, Amazon R. system, Brazil (Ref. 26282). - 
Characidae Phallobrycon adenacanthus Menezes, Ferreira & Netto-Ferreira, 2009 Fr, Thr native   4.00 cm SL male/unsexed  Known from the upper rio Xingu in the states of Pará and Mato Grosso. A single specimen was found in sympatry with Bryconadenos weitzmani in rio Curuá, tributary of rio Iriri, rio Xingu basin. The population from Campinápolis, rapids in rio Culuene, rio Xingu basin is under severe threat due to the recent impoundment of the rio Culuene in the exact stretch where the specimens were collected, and other known populations should be preserved. (Ref. 81937). - 
Poeciliidae Phalloceros alessandrae Lucinda, 2008 Fr native    1.75 cm SL male/unsexed ;2.47 cm SL female  Found in flooded areas on margins nearby Antonina (Paraná) and rio Dois de Fevereiro, which flows into the Baía de Paranaguá (Ref. 76852). + 
Poeciliidae Phalloceros anisophallos Lucinda, 2008 Fr native    2.82 cm SL male/unsexed ;4.51 cm SL female  Known from the drainages of rio Parati, rio Barra Grande, rio São Roque, rio Taquari and rio Itinguçu (small coastal drainages of Rio de Janeiro) (Ref. 76852). + 
Poeciliidae Phalloceros aspilos Lucinda, 2008 Fr native    2.38 cm SL male/unsexed ;3.83 cm SL female    + 
Poeciliidae Phalloceros buckupi Lucinda, 2008 Fr native    1.99 cm SL male/unsexed ;3.29 cm SL female  Known from rio Jacareí drainage and neighbouring, which flows into the Baía de Paranaguá in the coast of Paraná State (Ref. 76852). + 
Poeciliidae Phalloceros caudimaculatus (Hensel, 1868) Fr, Br native  Barrigudinho (Portuguese), Guaru (Portuguese), Guaru guaru (Portuguese)   3.50 cm SL male/unsexed ;6.00 cm TL female  Recorded from the Pardo River (Ref. 27745), Caracu and Sao Pedro streams, tributaries of the Paraná river (Ref. 26076). Found in Córrego Barreiro (Ref. 53011). Also recorded from the Patos lagoon (Ref. 58359). Also Ref. 1739. + 
Poeciliidae Phalloceros elachistos Lucinda, 2008 Fr endemic    1.99 cm SL male/unsexed ;2.78 cm SL female    + 
Poeciliidae Phalloceros enneaktinos Lucinda, 2008 Fr native    2.42 cm SL male/unsexed ;3.58 cm SL female    + 
Poeciliidae Phalloceros harpagos Lucinda, 2008 Fr native  Barrigudinho (Portuguese)   3.41 cm SL male/unsexed ;4.68 cm SL female  Known from rio Itaboapana to rio Araranguá (Ref. 76852). + 
Poeciliidae Phalloceros heptaktinos Lucinda, 2008 Fr native    2.40 cm SL male/unsexed ;3.03 cm SL female  Found only in the tributarues of the arroio dos Ratos, Jacuí basin in Mariana Pimentel, Rio Grande do Su(Ref. 76852). + 
Poeciliidae Phalloceros leptokeras Lucinda, 2008 Fr native    2.37 cm SL male/unsexed ;3.65 cm SL female    + 
Poeciliidae Phalloceros leticiae Lucinda, 2008 Fr native    1.66 cm SL male/unsexed  Found in the upper rio Araguaia, main tributary to the rio Tocantins (Ref. 76852). + 
Poeciliidae Phalloceros lucenorum Lucinda, 2008 Fr native    2.80 cm SL male/unsexed ;3.70 cm SL female  Known from Rio Juquiá, a tributary to the drainage of the rio Ribeira de Iguape in São Paulo (Ref. 76852). + 
Poeciliidae Phalloceros malabarbai Lucinda, 2008 Fr native    2.22 cm SL male/unsexed ;3.21 cm SL female  Known only from the type locality, creek near Itapoá, São Francisco do Sul, Santa Catarina (Ref. 76852). + 
Poeciliidae Phalloceros megapolos Lucinda, 2008 Fr native    2.34 cm SL male/unsexed ;3.97 cm SL female  Known from the drainages of the rio São João, rio Cubatão (Norte) and small adjacent drainages, which flows into the Baía de Guaratuba in Paraná State (Ref. 76852). + 
Poeciliidae Phalloceros mikrommatos Lucinda, 2008 Fr native    2.04 cm SL male/unsexed ;2.70 cm SL female  Found in the rio João de Tiba drainage, a coastal drainage in Bahia State (Ref. 76852). + 
Poeciliidae Phalloceros ocellatus Lucinda, 2008 Fr native    1.85 cm SL male/unsexed ;2.52 cm SL female  Known from coastal drainages of Bahia and Espírito Santo States between Prado and Sooretama (Ref. 76852). + 
Poeciliidae Phalloceros pellos Lucinda, 2008 Fr native    2.41 cm SL male/unsexed ;3.32 cm SL female  Found in small coastal drainages flowing into Baía de Paranaguá in Paraná State (Ref. 76852). + 
Poeciliidae Phalloceros reisi Lucinda, 2008 Fr native    2.72 cm SL male/unsexed ;4.99 cm SL female  Found in the headwaters of rio Tietê, rio Paraíba do Sul, rio Ribeira de Iguape, and small coastal drainages in São Paulo State (Ref. 76852). + 
Poeciliidae Phalloceros spiloura Lucinda, 2008 Fr native    2.24 cm SL male/unsexed ;3.36 cm SL female  Known from the Rio Iguaçu and coastal drainages of Rio Grande do Sul and Santa Catarina, including the rio Tubarão, rio Itajaí-Açu, rio Itapocu, rio Mampituba, rio Cubatão (North), rio Tramandaí drainages (Ref. 76852). + 
Poeciliidae Phalloceros titthos Lucinda, 2008 Fr native    2.58 cm SL male/unsexed ;4.52 cm SL female  Known from the coastal drainages flowing to Baia de Guaratuba and Baia de Paranaguá in Paraná State (Ref. 76852). + 
Poeciliidae Phalloceros tupinamba Lucinda, 2008 Fr native    2.74 cm SL male/unsexed ;4.40 cm SL female  Found in rio Itamambuca and rio Macacu drainages, small coastal drainages of São Paulo and Rio de Janeiro States (Ref. 76852). + 
Poeciliidae Phalloceros uai Lucinda, 2008 Fr native  Barrigudinho (Portuguese)   1.66 cm SL male/unsexed ;3.38 cm SL female  Known from the Rio das Velhas, rio São Francisco basin (Ref. 76852). + 
Poeciliidae Phalloptychus eigenmanni Henn, 1916 Fr endemic  Barrigudinho (Portuguese), Barrigudo (Portuguese)   2.50 cm SL male/unsexed ;3.50 cm female  Known from the Rio Catu in Alagoinhas, Baia. - 
Poeciliidae Phalloptychus januarius (Hensel, 1868) Fr native  Barrigudinho (Portuguese), Guaru (Portuguese), Guaru guaru (Portuguese)   2.50 cm SL male/unsexed ;4.00 cm female  Known from the Rio de Janeiro to the Rio Grande do Sul. Recorded from the Patos lagoon (Ref. 58359). + 
Poeciliidae Phallotorynus fasciolatus Henn, 1916 Fr, Thr endemic  Barrigudinho (Portuguese), Guaru (Portuguese), Guarú (Portuguese)   2.50 cm SL male/unsexed ;3.50 cm female  Known from the Rio Paraiba basin in Sao Paulo (Ref. 26130) and upper Rio Tietê drainage in Paranapiacaba (Ref. 56059). Status of Threat: Endangered (MMA, 2004); conservation status uncertain, probably seriously endangered or even extinct (Ref. 56059). - 
Poeciliidae Phallotorynus jucundus Ihering, 1930 Fr, Thr native  Barrigudinho (Portuguese), Guaru (Portuguese), Guarú (Portuguese)   2.50 cm SL male/unsexed ;3.00 cm female  Known from the Rio Parana basin in Sao Paulo (Ref. 26130). Found in the Upper Pardo River basin in Grande River drainage (Ref. 50894). Status of Threat: Endangered (MMA, 2004). Critically Endangered in the State of São Paulo (São Paulo, 1998). - 
Poeciliidae Phallotorynus pankalos Lucinda, Rosa & Reis, 2005 Fr native   2.79 cm SL male/unsexed  Type locality, affluent of Rio Iguatemi (Rio Paraná drainage), tributary to Rio Puitá, on the road to Paranhos on creek ar fazenda Sossego, Tacuru, Mato Grosso do Sul, MZUSP 79671 (holotype of Phallotorynus pankalos, 2.71 cm SL, female). Known only from the type locality, affluent of Rio Iguatemi, Rio Parana drainage in Mato Grosso do Sul (Ref. 56059). - 
Poeciliidae Phallotorynus victoriae Oliveros, 1983 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  2.30 cm SL male/unsexed  Found in Mato Grosso do Sul State (Ref. 50894). - 
Characidae Phenacogaster apletostigma Lucena & Gama, 2007 Fr native   4.09 cm SL male/unsexed  Known from the Araguari River system in Amapá State (Ref. 75796). + 
Characidae Phenacogaster beni Eigenmann, 1911 Fr native   3.68 cm SL male/unsexed  Recorded from Rio Guapore basin (Ref. 598). - 
Characidae Phenacogaster calverti (Fowler, 1941) Fr native   6.00 cm SL male/unsexed ;8.00 cm TL female  Found in coastal drainages of Ceará and Paraíba (Ref. 36811). Recorded from Fortaleza, Ceará (Ref. 26633). + 
Characidae Phenacogaster franciscoensis Eigenmann, 1911 Fr native  Lambari (Portuguese)   4.20 cm SL male/unsexed  Recorded from Rio Sao Francisco (Ref. 598, 36811). + 
Characidae Phenacogaster jancupa Malabarba & Lucena, 1995 Fr native  Lambari (Portuguese)  4.70 cm SL male/unsexed  Known only from ribeirão Espinheiro, a creek of the rio Cuiabá drainage, upper rio Paraguay, Mato Grosso (Ref. 26633). Also Ref. 36811. - 
Characidae Phenacogaster lucenae Souza, Mattox, Vita, Ochoa, Melo & Oliveira, 2023 Fr native   3.80 cm SL male/unsexed  Type locality of the holotype of Phenacogaster lucenae: stream affluent of Rio Curuá, Rio Xingu, Amazon basin, Novo Progresso, Pará (Ref. 128855). - 
Characidae Phenacogaster ojitata Lucena & Malabarba, 2010 Fr native   3.63 cm SL male/unsexed  Type locality, Pará: Rio Curuá (Serra do Cachimbo), MZUSP 30551 (holotype of Phenacogaster ojitatus, 3.63 cm SL) (Ref. 84092). + 
Characidae Phenacogaster pectinata (Cope, 1870) Fr native    4.50 cm SL male/unsexed  Known from the Amazon (Ref. 36811) and Acre River basins (Ref. 97592). - 
Characidae Phenacogaster retropinnus Lucena & Malabarba, 2010 Fr native   5.12 cm SL male/unsexed  Type locality, Mato Grosso: Rio Aripuanã (3 km abaixo da cachoeira Dardanelos, sistema do Rio Madeira), INPA 31367 (holotype of Phenacogaster retropinnus, 4 cm SL). Known from Sistemas do rios Negro, Madeira e Xingu (Ref. 84092). Found in Machado river basin (Ref. 97589). + 
Characidae Phenacogaster suborbitalis Ahl, 1936 Fr native  Piaba (Portuguese)  5.50 cm SL male/unsexed  Probably found in the eastern coast of Brazil (Ref. 36811). - 
Characidae Phenacogaster tegatus (Eigenmann, 1911) Fr native    3.50 cm SL male/unsexed  Known from the Rio Paraguai, Cáceres and vicinity in Mato Grosso (Ref. 26633). Also Ref. 36811. + 
Heptapteridae Phenacorhamdia boliviana (Pearson, 1924) Fr native    5.80 cm SL male/unsexed  Found in the Acre River basin (Ref. 97592). - 
Heptapteridae Phenacorhamdia hoehnei (Miranda Ribeiro, 1914) Fr endemic  Bagrinho (Portuguese), Lobó (Portuguese), Mandizinho (Portuguese)  3.80 cm SL male/unsexed  Known from Taquari River in Paraguay River drainage (Ref. 36914). Type locality: Rio Taquari, Mato Grosso, Brazil (Ref. 26282, 6868). - 
Heptapteridae Phenacorhamdia somnians (Mees, 1974) Fr endemic  Bagrinho (Portuguese), Mandizinho (Portuguese)  6.30 cm SL male/unsexed  Known from Das Morte River basin (Ref. 36914). Type locality: Sangadina, trib. of Rio das Mortes, 2 km from Xaventina, Mato Grosso, Brazil (Ref. 6868, 26282). - 
Heptapteridae Phenacorhamdia tenebrosa (Schubart, 1964) Fr endemic  Baggrinho (Portuguese), Lobó (Portuguese), Mandizinho (Portuguese)   7.54 cm SL male/unsexed  Known from the upper Paraná and São Francisco River basins (Ref. 36914). Type locality: Rio Mogi Guaçu, Brazil (Ref. 6868, 26282). + 
Heptapteridae Phenacorhamdia unifasciata Britski, 1993 Fr endemic  Bagrinho (Portuguese), Lobó (Portuguese), Mandizinho (Portuguese)  6.20 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 36914). Type locality: Ribeira Sao Santana, trib. of R. Sao Bartolomeu, 15°50'N, 47°40'W, Dist. Federal, Brazi (Ref. 26282). - 
Pimelodidae Phractocephalus hemioliopterus (Bloch & Schneider, 1801) Fr, Fi native  Pirarara (Portuguese), Cajaro (Portuguese), Laitu (Portuguese), Parabebe (Portuguese), Pirabepre (Portuguese), Torai (Portuguese), Uarara (Portuguese), Uarará (Portuguese)   135 cm TL male/unsexed    + 
Phreatobiidae Phreatobius cisternarum Goeldi, 1905 Fr, Br endemic   5.50 cm SL male/unsexed  Found in phreatic environments in the Marajó Island, mouth of the Amazon River (Ref. 36914). - 
Phreatobiidae Phreatobius dracunculus Shibatta, Muriel-Cunha & De Pinna, 2007 Fr native   3.81 cm SL male/unsexed  Known from a hand-dug well in the village of Rio Pardo in Rondônia, in the drainage area of the Rio Branco (tributary to Rio Jaci-Paraná, itself a tributary to Rio Madeira, Amazon basin) (Ref. 72403). - 
Characidae Phycocharax rasbora Ohara, Mirande & Lima, 2017 Fr native   3.32 cm SL male/unsexed  Known only from the type locality: upper rio Braço Norte, a right-bank tributary of the rio Peixoto de Azevedo, part of rio Teles Pires drainage, rio Tapajós basin. Rio Braço Norte drains the Serra do Cachimbo in the northern Mato Grosso State, Brazilian Amazon (Ref. 116744). - 
Doradidae Physopyxis ananas Sousa & Rapp Py-Daniel, 2005 Fr native    2.20 cm SL male/unsexed  Known throughout the lowlands in the entire Amazon, including rio Negro (Ref. 56903). - 
Doradidae Physopyxis cristata Sousa & Rapp Py-Daniel, 2005 Fr native    2.27 cm SL male/unsexed  Known only from the middle portion of the rio Negro basin (Amazon drainage) in Amazonas (Ref. 56903). - 
Doradidae Physopyxis lyra Cope, 1872 Fr native    3.50 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Characidae Piabarchus analis (Eigenmann, 1914) Fr native    4.90 cm SL male/unsexed    - 
Characidae Piabarchus torrenticola Mahnert & Géry, 1988 Fr native   7.70 cm SL male/unsexed   - 
Characidae Piabina anhembi da Silva & Kaefer, 2003 Fr native    Type locality, Rio Paraitinga na cachoeira da Porteira, afluente do rio Tietê, São Paulo, 23°31'37"S, 45°45'52"W (Ref. 50838). + 
Characidae Piabina argentea Reinhardt, 1867 Fr native  Piaba (Portuguese)   7.30 cm SL male/unsexed  Known from Córrego Barreiro (Ref. 53011). Type locality, Rio das Velhas (Ref. 33021). + 
Iguanodectidae Piabucus dentatus (Koelreuter, 1763) Fr native  Bongoni (Portuguese), Sardinha-de-gato (Portuguese)   12.90 cm SL male/unsexed    + 
Iguanodectidae Piabucus melanostoma Holmberg, 1891 Fr native    11.50 cm SL male/unsexed    - 
Serrasalmidae Piaractus brachypomus (Cuvier, 1818) Fr, Fi native  Caranha (Portuguese), Pirapitinga (Portuguese), Tambaqui (Portuguese)   88.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39031). Found in fish markets in Santarém. + 
Serrasalmidae Piaractus mesopotamicus (Holmberg, 1887) Fr, Fi, Aq native  Pacu caranha (Portuguese), Caranha (Portuguese), Pacu (Portuguese), Pacu branco (Portuguese), Pacu guaçu (Portuguese), Pacu-caranha (Portuguese) scarce (very unlikely) 40.50 cm SL male/unsexed  Found in Piracicaba river (Ref. 50076). Widely farmed in Southern Brazil (Ref. 32894). + 
Heptapteridae Pimelodella australis Eigenmann, 1917 Fr endemic  Mandi-chorão (Portuguese), Mandi (Portuguese)   10.60 cm SL male/unsexed  Known from the Uruguay River basin and coastal river drainages from Tubarão River in Santa Catarina to coastal lagoons of Rio Grande do Sul (Ref. 36914). Recorded from the Patos lagoon (Ref. 58359). - 
Heptapteridae Pimelodella avanhandavae Eigenmann, 1917 Fr endemic  Mandi (Portuguese), Mandi-chorão (Portuguese), Mandizinho (Portuguese)  14.20 cm SL male/unsexed  Known from the Tietê River basin (Ref. 36914). Type locality: Rio Tieté at Salto Avanhandava, Brazil (Ref. 26282, 6868). + 
Heptapteridae Pimelodella bockmanni Slobodian & Pastana, 2018 Fr native   10.12 cm TL male/unsexed  Type locality of Pimelodella bockmanni Manicoré, Rio Branco basin, tributary of Rio Branco, near the Parque Nacional dos Campos Amazônicos, Amazonas, Brazil, MZUSP 121925. Also known from Jiparaná and Marmelos river basins, Rio Madeira, Amazonas and Rondonia States. - 
Heptapteridae Pimelodella boliviana Eigenmann, 1917 Fr native  Bagre (Portuguese), Cunshi (Portuguese)   9.00 cm SL male/unsexed   - 
Heptapteridae Pimelodella boschmai Van der Stigchel, 1964 Fr endemic  Mandi (Portuguese), Mandi-chorão (Portuguese), Mandizinho (Portuguese)   10.00 cm SL male/unsexed  Known from Mogi Guaçu River basin (Ref. 36914). Also Ref. 6868. Type locality: Rio Mogi-Guassu, below Emas falls, Pirassununga, Brazil (Ref. 26282). - 
Heptapteridae Pimelodella brasiliensis (Steindachner, 1877) Fr endemic  Mandi-chorão (Portuguese), Bagre (Portuguese), Chorão (Portuguese), Cumbáca (Portuguese), Jandiá (Portuguese), Mandí chorão (Portuguese), Mandizinho (Portuguese)  18.00 cm TL male/unsexed  Known from Paraíba do Sul River basin (Ref. 36914). Type locality: Rio Parahyba, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella breviceps (Kner, 1858) Fr endemic  Mandi-chorão (Portuguese)  36.00 cm SL male/unsexed  Known from the Upper Negro River basin (Ref. 36914). Type locality: Marabitanos, Brazil (Ref. 6868, 26282). - 
Heptapteridae Pimelodella cristata (Müller & Troschel, 1849) Fr native  Mandi (Portuguese), Bagre (Portuguese)   34.00 cm SL male/unsexed    + 
Heptapteridae Pimelodella dorseyi Fowler, 1941 Fr endemic  Mandi-chorão (Portuguese)  12.40 cm TL male/unsexed  Known from Jaguaribe River basin (Ref. 36914). Type locality: Rio Salgade, Icó, Ceará, Brazil (Ref. 26282). Also Ref. 6868. - 
Heptapteridae Pimelodella eigenmanni (Boulenger, 1891) Fr endemic  Mandi-chorão (Portuguese)   24.50 cm TL male/unsexed  Known from Paraíba do Sul River basin (Ref. 36914). Type locality: Sao Paulo, Brazil (Ref. 26282). Also Ref. 6868. - 
Heptapteridae Pimelodella eigenmanniorum (Miranda Ribeiro, 1911) Fr endemic  Mandi-chorão (Portuguese)   Known from Paraíba do Sul River basin and coastal rivers in Rio de Janeiro (Ref. 36914). - 
Heptapteridae Pimelodella enochi Fowler, 1941 Fr endemic  Mandi-chorão (Portuguese)  5.90 cm TL male/unsexed  Known from Paraíba River basin in Paraíba State (Ref. 36914). Type locality: Açude Piloes, Rio Parahyba, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella gracilis (Valenciennes, 1835) Fr native  Mandi-chorão (Portuguese), Chorão (Portuguese), Chum-chum (Portuguese), Chundu (Portuguese), Dubu (Portuguese), Mandi mole (Portuguese), Mandim (Portuguese), Mandizinho (Portuguese)   18.00 cm SL male/unsexed  Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). + 
Heptapteridae Pimelodella harttii (Steindachner, 1877) Fr endemic   15.00 cm SL male/unsexed  Known from Paraíba do Sul River basin (Ref. 36914). - 
Heptapteridae Pimelodella hasemani Eigenmann, 1917 Fr native  Mandi-chorão (Portuguese)  8.10 cm TL male/unsexed  Known from Madeira River basin (Ref. 36914). Type locality: San Antonio de Rio Madeira, Amazon system, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella howesi Fowler, 1940 Fr native    7.90 cm SL male/unsexed    - 
Heptapteridae Pimelodella humeralis Slobodian, Akama & Dutra, 2017 Fr native   95.80 cm TL male/unsexed  Type locality of Pimelodella humeralis, Pará, Almeirim, Rio Ipitinga, Rio Jari basin, left bank tributary of the Rio Amazonas. Known from the Rio Ipitinga, which is a major right bank tributary of the Rio Jari that drains the eastern Guiana Shield into the lower Amazon. The Ipitinga headwaters are located in the Colinas do Amapá geomorphological formation (ca. 300 m elevation), and has many rapids along the main channel (Ref. 118150). - 
Heptapteridae Pimelodella ignobilis (Steindachner, 1907) Fr endemic  Bagre (Portuguese)  10.00 cm SL male/unsexed  Known from Cubatão River basin (southern) in Santa Catarina State (Ref. 36914). Type locality: Rio Cubatao, Santa Catharina near Theresopolis, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella itapicuruensis Eigenmann, 1917 Fr endemic  Mandi-chorão (Portuguese)  10.40 cm SL male/unsexed  Known from the Itapicurú River basin (Ref. 36914). Type locality: Rio Itapicurú at Queimadas, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella kronei (Miranda Ribeiro, 1907) Fr endemic  Blind catfish (English), Ceguinho (Portuguese), Bagre cego (Portuguese), Bagre ceguinho (Portuguese)   20.20 cm SL male/unsexed  Found in caves in the Ribeira do Iguape River basin in Sao Paulo (Ref. 36914). Also in upper Ribeira river valley (Ref. 38979). Type locality: Cavernas das Areieas, Iporanga, Sao Paulo, Brazil (Ref. 26828, 6868) . + 
Heptapteridae Pimelodella lateristriga (Lichtenstein, 1823) Fr endemic  Mandi (Portuguese), Canito (Portuguese), Chorão (Portuguese), Chué (Portuguese), Jundiá (Portuguese), Mandi chinga (Portuguese), Mandi roncador (Portuguese), Mandi-chorão (Portuguese), Mandizinho (Portuguese), Xué (Portuguese)   20.20 cm TL male/unsexed  Known from Paraíba do Sul River basin (Ref. 36914). Also Ref. 6868. - 
Heptapteridae Pimelodella laurenti Fowler, 1941 Fr endemic  Mandi-chorão (Portuguese), Jundiá (Portuguese), Mandi (Portuguese)  7.10 cm SL male/unsexed  Known from the lower São Francisco River basin (Ref. 36914). Type locality: Rio Sao Francisco, Jatobá, Pernambuco, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella longipinnis (Borodin, 1927) Fr endemic  Mandi (Portuguese), Mandi-chorão (Portuguese), Mandizinho (Portuguese)  8.80 cm SL male/unsexed  Known from São Paulo State river basins (Ref. 36914). Also Ref. 6868. - 
Heptapteridae Pimelodella meeki Eigenmann, 1910 Fr endemic  Mandi (Portuguese), Mandi-chorão (Portuguese), Mandizinho (Portuguese)   14.10 cm TL male/unsexed  Known from Tietê River basin (Ref. 36914). Type locality: Sapina and Mogy das Cruzes, Sao Paulo, Brazil (Ref. 26282). Also Ref. 6868. + 
Heptapteridae Pimelodella megalura Miranda Ribeiro, 1918 Fr endemic  Mandi-chorão (Portuguese), Chum-chum (Portuguese)  22.00 cm TL male/unsexed  Known from the upper Paraguay River basin (Ref. 36914). Type locality: Sao Luiz de Cáceres, Mato Grosso, Paraguay basin, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella notomelas Eigenmann, 1917 Fr endemic  Mandi-chorão (Portuguese), Chum chum (Portuguese)   6.00 cm TL male/unsexed  Known from the upper Paraguay River basin (Ref. 36914). Type locality: San Luiz de Cáceres, Paraguay basin, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella papariae (Fowler, 1941) Fr native  Mandi (Portuguese)  13.50 cm TL male/unsexed  Type locality: Lago Papary, Rio Grande do Norte, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella pappenheimi Ahl, 1925 Fr endemic  Mandi-chorão (Portuguese), Mandizinho (Portuguese)  15.00 cm TL male/unsexed ;14.80 cm TL female 6.3 TL Known from Itajaí-Açú, Itapocú and Cubatão River basins in Santa Catarina State and Paranaguá River basin in Paraná State (Ref. 36914). Type locality: Rio Pedro at Humboldt, Santa Catherina, Brazil (Ref. 6868, 26282). - 
Heptapteridae Pimelodella parnahybae Fowler, 1941 Fr endemic  Mandi-chorão (Portuguese)   9.50 cm TL male/unsexed  Known from Parnaíba River basin (Ref. 36914). Type locality: Rio Parnahyba, Therezina, Piauhy, Brazil (Ref. 26282, 6868). + 
Heptapteridae Pimelodella pectinifer Eigenmann & Eigenmann, 1888 Fr endemic  Mandi-chorão (Portuguese)   15.00 cm SL male/unsexed  Known from Muriaé River basin (Ref. 36914). Type locality: Rio Muriaé at Campos, 3 mi. from town, Brazil (Ref. 26282). - 
Heptapteridae Pimelodella robinsoni (Fowler, 1941) Fr endemic  Mandi chorão (Portuguese), Jundiá (Portuguese)  9.70 cm TL male/unsexed  Known from lower São Francisco River basin (Ref. 36914). Type locality: Sao José do Egito, Pernambuco, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella rudolphi Miranda Ribeiro, 1918 Fr endemic  Mandi (Portuguese), Mandi-chorão (Portuguese), Mandizinho (Portuguese)  10.50 cm SL male/unsexed  Known from São Paulo Sate (Ref. 36914). Occurs in Sorocaba, Rio Tiete, Rio Feio and Rio Tamanduatei (Ref. 6868). - 
Heptapteridae Pimelodella serrata Eigenmann, 1917 Fr native    11.00 cm TL male/unsexed    - 
Heptapteridae Pimelodella spelaea Trajano, Reis & Bichuette, 2004 Fr native   8.05 cm SL male/unsexed  Type locality, Subterranean stream tributary to São Bernardo R. inside São Bernardo Cave, upper Tocantins R. basin, São Domingos, State of Goiás, 13°49'S, 46°21'W (Ref. 54621). - 
Heptapteridae Pimelodella steindachneri Eigenmann, 1917 Fr endemic  Mandi-chorão (Portuguese)   21.20 cm SL male/unsexed  Type locality: Amazon Basin. Occurs in Para, Cudajas, Santarem, Rio Puty. Marajo and Rio Madeira (Ref. 6868). Also Ref. 36914. - 
Heptapteridae Pimelodella taeniophora (Regan, 1903) Fr endemic  Mandi-chorão (Portuguese)  8.50 cm TL male/unsexed  Known from Paraguay River basin (Ref. 36914). - 
Heptapteridae Pimelodella taenioptera Miranda Ribeiro, 1914 Fr endemic  Mandi-chorão (Portuguese), Chum-chum (Portuguese)   12.10 cm SL male/unsexed  Known from the upper Paraguay River basin (Ref. 36914). Type locality: Tapirapoan, Rio Sepotuba, La Plata basin, Brazil (Ref. 26282). Also Ref. 6868. - 
Heptapteridae Pimelodella transitoria Miranda Ribeiro, 1907 Fr endemic  Mandi (Portuguese), Mandi-tinga (Portuguese)   13.00 cm SL male/unsexed  Known from Ribeira de Iguape River basin (Ref. 36914). Also found in Betari river basin in southeastern Brazil (Ref. 38979). Type locality: Ribeirao do Alambary, Iporanga, Sao Paulo, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella vittata (Lütken, 1874) Fr endemic  Choralambre (Portuguese), Chué (Portuguese), Mandi-chorão (Portuguese), Xué (Portuguese)  9.70 cm SL male/unsexed  Known from the upper São Francisco River basin (Ref. 36914). Type locality: Rio das Velhas, Minas Gerais, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella witmeri Fowler, 1941 Fr endemic  Mandi-chorão (Portuguese)  16.80 cm TL male/unsexed  Known from Jaguaribe River basin (Ref. 36914). Type locality: Rio Jaguaribe, Oros, Ceara, Brazil (Ref. 26282, 6868). - 
Heptapteridae Pimelodella wolfi (Fowler, 1941) Fr endemic  Mandi (Portuguese)  11.60 cm TL male/unsexed  Known from Choró River basin (Ref. 36914). Type locality: Rio Choró, Ceará, Brazil (Ref. 26282, 6868). - 
Pimelodidae Pimelodina flavipinnis Steindachner, 1876 Fr, Fi native  Mandi moela (Portuguese), Fura calça (Portuguese), Moela (Portuguese)   39.00 cm SL male/unsexed  Type locality: Amazonas R. at Para. Found in fish markets in Santarém (Ref. 12202). + 
Pimelodidae Pimelodus absconditus Azpelicueta, 1995 Fr native  Mandi-pintado (Portuguese)   28.70 cm TL male/unsexed  Known from the Uruguay River (Ref. 79585). - 
Pimelodidae Pimelodus albofasciatus Mees, 1974 Fr native    29.50 cm SL male/unsexed    + 
Pimelodidae Pimelodus altissimus Eigenmann & Pearson, 1942 Fr native     Known from the Amazon River basin (Ref. 36506). - 
Pimelodidae Pimelodus argenteus Perugia, 1891 Fr native  Bagre (Portuguese)   25.00 cm SL male/unsexed  Found in Pantanal (Ref. 81048). + 
Pimelodidae Pimelodus atrobrunneus Vidal & Lucena, 1999 Fr endemic  Mandi (Portuguese)  25.70 cm TL male/unsexed  Known from the upper Uruguay River basin (Ref. 36506). - 
Pimelodidae Pimelodus blochii Valenciennes, 1840 Fr, Br, Fi native  Mandi (Portuguese), Bagre-amarelo (Portuguese), Bagre-de-areia (Portuguese), Iriceca (Portuguese), Irideca (Portuguese), Mandí cabeça de ferro (Portuguese), Mandi-pintado (Portuguese), Mandiamarelo (Portuguese), Mandii (Portuguese), Mandijuba (Portuguese), Mandiú (Portuguese), Pintado (Portuguese)   35.00 cm TL male/unsexed  Occurs in Rio Machado and the Amazon basin (Ref. 27188). + 
Pimelodidae Pimelodus britskii Garavello & Shibatta, 2007 Fr native    36.00 cm SL male/unsexed 6.35 Widely distributed throughout the rio Iguaçu basin (Ref. 58939). - 
Pimelodidae Pimelodus fur (Lütken, 1874) Fr, Fi endemic  Mandi (Portuguese), Mandi branco (Portuguese), Papa isca (Portuguese)   28.00 cm SL male/unsexed  Known from Das Velhas River basin in São Francisco River drainage (Ref. 36506). Found in Piracicaba river (Ref. 50076). Type locality: Rio das Velhas, Minas Gerais, Brazil (Ref. 26282, 6868). Also Ref. 31923. - 
Pimelodidae Pimelodus halisodous Ribeiro, Lucena & Lucinda, 2008 Fr native   11.07 cm SL male/unsexed  Found in the upper and middle sections of the rio Tocantins drainage (Ref. 79502). - 
Pimelodidae Pimelodus joannis Ribeiro, Lucena & Lucinda, 2008 Fr native   7.69 cm SL male/unsexed  Found in the upper and middle sections of the rio Tocantins drainage (Ref. 79502). - 
Pimelodidae Pimelodus luciae Rocha & Ribeiro, 2010 Fr native   8.72 cm SL male/unsexed  Type locality, state of Pará: rio Itacaiúnas, Cachoeira Carreira Comprida, Caldeirão, Poço de Pedral, Serra dos Carajás, municipality of Parauapeba, rio Tocantins basin, MPEG 3174 (holotype of Pimelodus luciae, 7.84 cm SL). Known from the rio Itacaiunas, rio Tocantins basin (Ref. 83451). - 
Pimelodidae Pimelodus maculatus Lacepède, 1803 Fr, Fi, Aq native  Mandi (Portuguese), Bagre (Portuguese), Bagre amarelo (Portuguese), Bagre branco (Portuguese), Bagre pintado (Portuguese), Curiacica da branca (Portuguese), Mandi amarelo (Portuguese), Mandi casaca (Portuguese), Mandi do salgado (Portuguese), Mandi juba (Portuguese), Mandi pintado (Portuguese), Mandi tinga (Portuguese), Mandiguaçu (Portuguese), Mandijuba (Portuguese), Mandiú (Portuguese), Pintado (Portuguese), Pintado-amarelo (Portuguese), Surubim-bagre (Portuguese) occasional (usually not seen) 51.00 cm TL male/unsexed 14.7 TL Known from São Francisco River basin (Ref. 36506). Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076), the Patos lagoon (Ref. 58359) and Piracicaba river (Ref. 50076). Also reported from the Uruguay River (Ref. 79585). Also Ref. 31923. + 
Pimelodidae Pimelodus microstoma Steindachner, 1877 Fr endemic   33.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36506) and upper rio Paraná (Ref. 87365). + 
Pimelodidae Pimelodus multicratifer Ribeiro, Lucena & Oyakawa, 2011 Fr native   19.80 cm SL male/unsexed  Type locality, São Paulo, confluence of the rios Pariquera and Pariquera-Mirim, near mouth to the rio Ribeira de Iguape, Pariquera-Açú, MZUSP 91287 (holotype of Pimelodus multicratifer, 19.8 cm SL). Known from Rio Ribeira de Iguape basin, Ilha Comprida, and rio Una do Prelado (Ref. 86673). - 
Pimelodidae Pimelodus mysteriosus Azpelicueta, 1998 Fr native   14.30 cm SL male/unsexed  Known from Paraná River basin (Ref. 36506). - 
Pimelodidae Pimelodus ornatus Kner, 1858 Fr native  Mandi (Portuguese), Aracimbora (Portuguese), Bagre (Portuguese), Bagre-cabeçudo (Portuguese), Cabeça dura (Portuguese), Cabeçudo (Portuguese), Caiauána (Portuguese), Guaraçoim pequeno (Portuguese), Mandi guaru (Portuguese), Mandí guaru (Portuguese), Mandí pimina (Portuguese), Mandi pinima (Portuguese), Mandí pinini (Portuguese), Mandí pintado (Portuguese), Mandipinima (Portuguese)   38.50 cm SL male/unsexed  Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). Found in Negro Negro and Cujaba (Ref. 6868). Also Ref. 36506. + 
Pimelodidae Pimelodus ortmanni Haseman, 1911 Fr native  Mandi (Portuguese), Pintado (Portuguese)   29.00 cm SL male/unsexed ;29.50 cm SL female  Known from Paraná River basin (Ref. 36506). Also Ref. 41259. - 
Pimelodidae Pimelodus pantaneiro Souza-Filho & Shibatta, 2007 Fr native    25.64 cm SL male/unsexed  Known from the upper rio Paraguia basin (Ref. 74927). - 
Pimelodidae Pimelodus paranaensis Britski & Langeani, 1988 Fr endemic   23.05 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 36506). - 
Pimelodidae Pimelodus pictus Steindachner, 1876 Fr native    11.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36506). + 
Pimelodidae Pimelodus platicirris Borodin, 1927 Fr endemic    16.00 cm SL male/unsexed  Known from Paraná River basin (Ref. 36506). - 
Pimelodidae Pimelodus pohli Ribeiro & Lucena, 2006 Fr native  Mandi (Portuguese)  15.03 cm SL male/unsexed  Found in several localities along the rio São Francisco drainage in Minas Gerais and Bahia (Ref. 75972). - 
Pimelodidae Pimelodus speciosus Costa e Silva, Ribeiro, Lucena & Lucinda, 2018 Fr native    Type locality of Pimelodus speciosus from Rio Tocantins below confluence with rio Santa Tereza, Peixe, Tocantins, Brazil, MCP 51687. - 
Pimelodidae Pimelodus stewarti Ribeiro, Lucena & Lucinda, 2008 Fr native   6.61 cm SL male/unsexed  Known from the upper and middle portions of the rio Tocantins drainage (Ref. 79502). - 
Pimelodidae Pimelodus tetramerus Ribeiro & Lucena, 2006 Fr native   17.20 cm SL male/unsexed  Type locality, Rio Palmeiras, rio Tocantins, Ponte Alta do Bom Jesus, MZUSP 85809 (holotype of Pimelodus tetramerus, 11.29 cm SL). Known from Tocantins and Tapajós rivers (Ref. 58353). - 
Pimelodidae Pinirampus pirinampu (Spix & Agassiz, 1829) Fr, Fi native  Pinarambu (Portuguese), Barba chata (Portuguese), Barbado (Portuguese), Barbado-branco (Portuguese), Barbudo (Portuguese), Gororoba (Portuguese), Grudado (Portuguese), Peixe moela (Portuguese), Pirabutão (Portuguese), Piramapu (Portuguese), Piranambu (Portuguese), Pirinampu (Portuguese)   120 cm TL male/unsexed    + 
Rivulidae Pituna brevirostrata Costa, 2007 Fr endemic   2.62 cm SL male/unsexed ;2.76 cm SL female  Known only from the type locality, a temporary lagoon in the rio Meia Ponte floodplains in Goiânia, Goiás, central Brazil (Ref. 57947). + 
Rivulidae Pituna compacta (Myers, 1927) Fr endemic   3.97 cm SL male/unsexed ;3.58 cm SL female  Found in temporary pools in the middle rio Tocantins basin, in typical savannah environment (Ref. 57947). + 
Rivulidae Pituna obliquoseriata Costa, 2007 Fr endemic   3.75 cm SL male/unsexed ;2.92 cm SL female  Found in a temporary swamp near rio das Mortes, rio Araguaia basin in central Brazil (Ref. 57947). - 
Rivulidae Pituna poranga Costa, 1989 Fr endemic   3.26 cm SL male/unsexed ;2.80 cm SL female  Found in temporary swamps in the middle rio Araguaia basin in Goiás and Tocantins (Ref. 57947). + 
Rivulidae Pituna schindleri Costa, 2007 Fr endemic   4.01 cm SL male/unsexed ;4.48 cm SL female  Found in seasonal pools in the lower rio Parnaíba basin in northeastern Brazil (Ref. 57947). - 
Rivulidae Pituna xinguensis Costa & Nielsen, 2007 Fr endemic   2.86 cm SL male/unsexed ;3.01 cm SL female  Found in a temporary swamp on a rio Xingu island near Altamira (Ref. 57947). - 
Sciaenidae Plagioscion auratus (Castelnau, 1855) Fr, Fi native  Corvina (Portuguese), Pescada preta (Portuguese), Cruvina (Portuguese), Curvina (Portuguese), Pescada (Portuguese)   34.60 cm SL male/unsexed    + 
Sciaenidae Plagioscion montei Soares & Casatti, 2000 Fr native  Corvina (Portuguese), Pescada (Portuguese), Pescada-branca (Portuguese)   34.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36888). Type locality, Rio Solimões, Lago Janauacá, INPA 15959 (holotype of Plagioscion montei) (Ref. 36888). + 
Sciaenidae Plagioscion squamosissimus (Heckel, 1840) Fr, Fi native  Corvina (Portuguese), Corvina branca (Portuguese), Cruvina (Portuguese), Curvina (Portuguese), Pescada (Portuguese), Pescada branca (Portuguese), Pescada branca do Amazonas (Portuguese), Pescada cacunda (Portuguese), Pescada do Piauí (Portuguese), Seleira (Portuguese), Taboaí (Portuguese), Tucano (Portuguese), Uatucupá (Portuguese) occasional (usually not seen) 80.00 cm TL male/unsexed 21.4 TL Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076) and Piracicaba river (Ref. 31923). Type localities: Rio Negro and Rio Branco, NMW 92.124 (holotype of Sciaena squamosissima, dry specimen); Rio Crixas, and affluent of Rion Araguay, MNHN 7503 (holotype of Johnius crouvina; Barra, at confluence of rio Grande and Rio São Francisco, NMW 57217 (holotype of Plagioscion francisci) (Ref. 36888). + 
Sciaenidae Plagioscion surinamensis (Bleeker, 1873) Fr, Fi native  Pescada-cacunda (Portuguese), Corvina (Portuguese), Corvina preta (Portuguese), Pescada branca (Portuguese)   70.00 cm TL male/unsexed 27.1 TL Known from the Amazon River basin (Ref. 36888). C: Refs. 36888, 94568; M: Ref. 94568; O: Ref. 94568. + 
Sciaenidae Plagioscion ternetzi Boulenger, 1895 Fr native  Corvina (Portuguese), Pescada (Portuguese), Surubina (Portuguese)   39.00 cm SL male/unsexed    + 
Characidae Planaltina britskii Menezes, Weitzman & Burns, 2003 Fr native    Type locality, Município de São José do Rio Preto, córrego da Barra Funda, trib. of rio Preto and trib. of rio Turvo, trib. of rio Grande, ca. 20°37'S. 49°23'W, Estado de São Paulo (Ref. 50838). + 
Characidae Planaltina glandipedis Menezes, Weitzman & Burns, 2003 Fr native    Type locality, Carumbataí, rio Corumbataí, ca. 22°13'S, 47°38'W, Estado de São Paulo (Ref. 50838). - 
Characidae Planaltina kaingang Deprá, da Graça, Pavanelli, Avelino & Oliveira, 2018 Fr native   5.37 cm SL male/unsexed ;5.46 cm SL female  Type locality of Planaltina kaingang: Rio Keller, tributary to the Rio Ivaı, upper Rio Parana basin (Ref. 128469). - 
Characidae Planaltina myersi Böhlke, 1954 Fr native    4.60 cm SL male/unsexed  Known from São Bartolomeu River in the upper Paraguay River basin (Ref. 38597). Type locality: Sarandi brook, Planaltina, Goiás, Brazil (Ref. 38597). - 
Loricariidae Planiloricaria cryptodon (Isbrücker, 1971) Fr native  Bode tábua (Portuguese)   21.50 cm SL male/unsexed  Known from the Amazon drainage and Purus River basin (Ref. 36389). + 
Dorosomatidae Platanichthys platana (Regan, 1917) Fr, Br native  Sardinha (Portuguese)  18.50 cm SL male/unsexed   + 
Doradidae Platydoras armatulus (Valenciennes, 1840) Fr native  Botoado (Portuguese), Abotoado (Portuguese), Armadillo (Portuguese), Bacu pedra (Portuguese), Roque-roque (Portuguese)   43.00 cm SL male/unsexed  Known from the Paraná River (Ref. 37054). + 
Doradidae Platydoras birindellii Sousa, Chaves, Akama, Zuanon & Sabaj, 2018 Fr native   18.20 cm TL male/unsexed  Type locality of Platydoras birindellii, Pará, rio Xingu, Pedra Preta, São Félix do Xingu. It appears to be endemic to the Xingu Basin where it is common in the main channel and its large tributary, the Iriri. It is absent from the lowermost stretch of the Xingu river, the so-called Xingu Ria. Its downstream limit presumably corresponds with the Xingu channel’s departure from the Brazilian Shield near Belo Monte. Populations are expected to decline in the Volta Grande Rapids, the stretch of the rio Xingu inundated or dewatered by the Belo Monte dam complex since it began its operations in 2015. Large populations of this species occur upstream of the impact zone of Belo Monte, in both the Xingu and its tributary the Iriri, but are threatened by unprecedented changes in land use associated with deforestation, farming, ranching and mining (Ref. 122376). + 
Doradidae Platydoras brachylecis Piorski, Garavello, Arce H. & Sabaj Pérez, 2008 Fr native  Graviola (Portuguese), Corro (Portuguese), Grangiola (Portuguese)  21.60 cm SL male/unsexed  Found in the rio Mearim, rio Pindaré, rio Itapecuru and rio Parnaíba basins in northeastern Brazil (Ref. 79514). + 
Doradidae Platydoras costatus (Linnaeus, 1758) Fr, Fi native  Roque roque (Portuguese), Abotoado (Portuguese), Bacu (Portuguese), Bacu-rebeca (Portuguese), Cambotá (Portuguese), Cuiú cuiú (Portuguese), Dukeru (Portuguese), Gragiola (Portuguese), Graviola (Portuguese), Graxiola (Portuguese), Kiri kiri (Portuguese), Salmo suairu (Portuguese), Serrotinho (Portuguese), Urutu (Portuguese), Yaranira (Portuguese)   24.00 cm SL male/unsexed  A juvenile in a stream of the rio Araguaia was recorded to clean the piscivorous characin Hoplias cf. malabaricus (Ref. 50806). + 
Doradidae Platydoras hancockii (Valenciennes, 1840) Fr native  Qui ri - qui ri (Portuguese)  15.00 cm TL male/unsexed   + 
Pimelodidae Platynematichthys notatus (Jardine, 1841) Fr, Fi native  Cara de gato (Portuguese), Caravataí (Portuguese), Coroatá (Portuguese), Coronel (Portuguese), Mandí dourado (Portuguese), Mestiço (Portuguese), Pintadinho (Portuguese), Pirá-tucandira (Portuguese), Pirainambu (Portuguese)   80.00 cm SL male/unsexed    + 
Pimelodidae Platysilurus mucosus (Vaillant, 1880) Fr native  Barba de arame (Portuguese), Bico de latão (Portuguese), Mandi (Portuguese), Piramutaba (Portuguese)   20.00 cm SL male/unsexed    + 
Aspredinidae Platystacus cotylephorus Bloch, 1794 Fr, Br native  Rabeca (Portuguese), Cachorro (Portuguese), Rebeca (Portuguese)   31.80 cm SL male/unsexed    + 
Pimelodidae Platystomatichthys sturio (Kner, 1858) Fr, Fi native  Braço de moça (Portuguese), Mandubé (Portuguese), Peixe lenha (Portuguese), Pirapeuaua (Portuguese), Surubim mena (Portuguese)   40.00 cm TL male/unsexed  Known from the Amazon River (Ref. 36506). + 
Apteronotidae Platyurosternarchus crypticus de Santana & Vari, 2009 Fr native   30.80 cm TL male/unsexed  Found in a limited region in the upper portions of the Rio Branco system of the Amazon basin in northeastern Roraima (Ref. 81220). - 
Apteronotidae Platyurosternarchus macrostoma (Günther, 1870) Fr native    40.00 cm TL male/unsexed  Found in the Amazon (Ref. 36886) and Machado River basins (Ref. 97589). + 
Trichomycteridae Plectrochilus diabolicus (Myers, 1927) Fr native   6.30 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39970). - 
Trichomycteridae Plectrochilus machadoi Miranda Ribeiro, 1917 Fr native    9.30 cm male/unsexed  Known from the Amazon River basin (Ref. 39970). Type locality: Río Solimoes, Brazil (Ref. 26282, 6868). - 
Rivulidae Plesiolebias altamira Costa & Nielsen, 2007 Fr endemic   1.75 cm SL male/unsexed ;1.81 cm SL female  Found in seasonal pools near the city of Altamira, rio Xingu drainage, rio Amazon basin in Estado do Pará (Ref. 57947). + 
Rivulidae Plesiolebias aruana (Lazara, 1991) Fr endemic   3.00 cm TL male/unsexed  Known from the Araguaia-Tocantins River basin (Ref. 36579). - 
Rivulidae Plesiolebias canabravensis Costa & Nielsen, 2007 Fr endemic   1.95 cm SL male/unsexed ;1.83 cm SL female  Found only in a seasonal lagoon near rio Canabrava, rio Tocantins basin (Ref. 57947). - 
Rivulidae Plesiolebias filamentosus Costa & Brasil, 2007 Fr native   1.99 cm SL male/unsexed ;2.07 cm SL female  Found in temporary pools in the southeastern portion of the Amazonian forest, middle rio Tocantins floodplains, between Itaguatins and Sampaio, Estado do Tocantins (Ref. 57947). - 
Rivulidae Plesiolebias fragilis Costa, 2007 Fr endemic   1.97 cm SL male/unsexed ;2.02 cm SL female  Found in seasonal swamps of the middle rio Araguaia basin in the region of ilha do Bananal, Estado do Tocantins (Ref. 57947). - 
Rivulidae Plesiolebias glaucopterus (Costa & Lacerda, 1989) Fr endemic   3.00 cm TL male/unsexed  Known from the Paraguay River basin (Ref. 36579). Also Ref. 21739. + 
Rivulidae Plesiolebias lacerdai Costa, 1989 Fr endemic   2.50 cm TL male/unsexed  Known from the Araguaia River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Plesiolebias xavantei (Costa, Lacerda & Tanizaki, 1988) Fr endemic   5.00 cm TL male/unsexed  Known from the middle Tocantins River basin (Ref. 36579). Also Ref. 27139. - 
Loricariidae Plesioptopoma curvidens Reis, Pereira & Lehmann A., 2012 Fr native   9.15 cm SL male/unsexed  Known from the type locality, the upper portion of the Rio Paraopeba, a tributary to the upper Rio São Francisco near Cristiano Otoni, Minas Gerais (Ref. 90155). - 
Potamotrygonidae Plesiotrygon iwamae Rosa, Castello & Thorson, 1987 Fr native  Raia (Portuguese), Arraia (Portuguese)   58.00 cm WD male/unsexed  Museum: Rio Salimões above Tefé, Amazonas, MZUSP 10153 (holotype, 601 DL, male) (Ref. 34195). - 
Achiridae Pnictes asphyxiatus (Jordan, 1889) Fr native  Sóia (Portuguese), Linguado (Portuguese)  9.57 cm SL male/unsexed  Known only from a collection from the Rio Amazonas and from the holotype, whose locality data is unclear (Goyaz, Brazil). The following comment accompanies the specimen label: " Probably somewhere in the Tocantins-Araguaia system. Collected after the conclusion of the Tayer Expedition, at Agassiz's specific request, for comparison with lower Rio Tocantins material. Isbrücker (1973:174) suggests that the locality is "Rio Araguaia drainage, upper course of Rio Vermelho at Goiás (15°57'S 50°07'W), but this has not been positively confirmed" (Ref. 49504). - 
Poeciliidae Poecilia parae Eigenmann, 1894 Fr, Br native  Barrigudinho (Portuguese), Guaru (Portuguese)   3.00 cm TL male/unsexed ;5.00 cm female  Found in the Amazon River (Ref. 26130). + 
Poeciliidae Poecilia picta Regan, 1913 Fr native  Barrigudinho (Portuguese), Guaru (Portuguese)  3.00 cm TL male/unsexed ;5.00 cm TL female  Also Ref. 26130. + 
Poeciliidae Poecilia reticulata Peters, 1859 Fr native  Mexicano (Portuguese), Barrigudinho (Portuguese), Barrigudinho-mexicano (Portuguese), Gúpi (Portuguese), Lebiste (Portuguese), Lebistes (Portuguese), Sarapintado (Portuguese)   5.00 cm SL male/unsexed ;6.00 cm SL female    + 
Poeciliidae Poecilia sarrafae Bragança & Costa, 2011 Fr native    Foun in Parnaíba and Mearim river basins in northeastern Brazil (Ref. 86528). - 
Poeciliidae Poecilia sphenops Valenciennes, 1846 Fr, Br introduced    7.50 cm SL male/unsexed    + 
Poeciliidae Poecilia vivipara Bloch & Schneider, 1801 Fr, Br native  Guaru (Portuguese), Barrigatintim (Portuguese), Barrigudinho (Portuguese), Bobó (Portuguese), Gargaru (Portuguese), Gargaú (Portuguese), Guaru guaru (Portuguese), Lebiste (Portuguese)   7.80 cm TL male/unsexed  Rio de Janeiro: in freshwater ditches and salt lagoon (Ref. 3157). Also recorded from the Patos lagoon (Ref. 58359). + 
Poeciliidae Poecilia waiapi Bragança, Costa & Gama, 2012 Fr native     - 
Crenuchidae Poecilocharax weitzmani Géry, 1965 Fr native    4.00 cm TL male/unsexed    + 
Loricariidae Pogonopoma obscurum Quevedo & Reis, 2002 Fr native   24.90 cm SL male/unsexed  Endemic to the upper reaches of the rio Uruguai, in the states of rio Grande do Sul and Santa Catarina, southern Brazil. Even after intense collections in the middle portion of rio Uruguai, the species has not been collected in this area. Type locality, rio Canoas, at road from Anita Garibaldi to Abdon Batista, Santa Catarina (Ref. 43112). - 
Loricariidae Pogonopoma parahybae (Steindachner, 1877) Fr native  Cascudo (Portuguese)   26.30 cm SL male/unsexed  Known from the Rio Paraiba, southeastern Brazil. Also Ref. 6868, 36817, 43112. + 
Loricariidae Pogonopoma wertheimeri (Steindachner, 1867) Fr native    22.30 cm SL male/unsexed  Currently known from three coastal river drainages in southeastern Brazil; the rio Mucuri, rio São Mateus, and rio Doce. Usually found in stretches of river with mid to strong water current and rocky or sandy bottom. However, some specimens were collected in the lago Juparanã, close to the mouth of rio Doce, a lentic habitat (Ref. 43112). Also Ref. 36817. + 
Polycentridae Polycentrus jundia Coutinho & Wosiacki, 2014 Fr native   2.83 cm SL male/unsexed  Found in the floodplain igarapés of the lower and upper rio Negro (Ref. 102655). - 
Polycentridae Polycentrus schomburgkii Müller & Troschel, 1849 Fr native    5.50 cm SL male/unsexed    + 
Characidae Poptella brevispina Reis, 1989 Fr native  Piaba (Portuguese)   8.82 cm SL male/unsexed  Occurs in the Amazon basin (Ref. 12225). Museum: Igarapé Apeu, Boa Vista, Castanhal, Pará, MZUSP 38562 (holotype of P. brevispina, 4.7 cm SL) (Ref. 27925). Also Ref. 36891. + 
Characidae Poptella compressa (Günther, 1864) Fr native    10.20 cm TL male/unsexed  Known from the Amazon River basin (Ref. 36891). + 
Characidae Poptella longipinnis (Popta, 1901) Fr native   6.90 cm SL male/unsexed  Known from the lower Tocantins River (Ref. 36891). + 
Characidae Poptella paraguayensis (Eigenmann, 1907) Fr native  Saia-branca (Portuguese)  10.20 cm SL male/unsexed  Type locality: Descalvados, Mato Grosso (Ref. 26282). + 
Apteronotidae Porotergus duende de Santana & Crampton, 2010 Fr native   18.40 cm TL male/unsexed ;10.40 cm TL female  Type locality, Amazonas, Rio Solimões, beach on north bank of Ilha Cuera, near Tefé, Mun. Alvarães, MCP 37357 (holotype of Porotergus duende, 10.4 cm TL, female) (Ref. 83661).  - 
Apteronotidae Porotergus gimbeli Ellis, 1912 Fr native    24.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). - 
Apteronotidae Porotergus gymnotus Ellis, 1912 Fr native  Itoui (Portuguese)  85.00 cm TL male/unsexed  Species found in the Amazon River basin (Ref. 36886) is a misidentification of Porotergus duende (Ref. 83661). - 
Ariidae Potamarius grandoculis (Steindachner, 1877) Fr, Br endemic    35.00 cm SL male/unsexed    - 
Batrachoididae Potamobatrachus trispinosus Collette, 1995 Fr native  Magangá (Portuguese)   5.00 cm SL male/unsexed  Known from the Araguaia/Tocantins River basin (Ref. 79892). Museum: small rocky pool near town of Jatobal, Rio Tocantins, Pará, MZUSP 4335 (holotype, 49.3 mm SL); USNM 330064 (paratype, 48 mm SL). Cachoeira immediately downstream from São Bento, Rio Araguaia, Pará, MNHG 2575.53 (paratype, 49.8 mm SL). + 
Trichomycteridae Potamoglanis anhanga (Dutra, Wosiacki & de Pinna, 2012) Fr native   1.31 cm SL male/unsexed  Found in igarapé da Extrema and igarapé Palhalzinho, tributaries to the rio Aripuanã, itself a tributary to the rio Madeira; igarapé Juruti Grande, tributary to the right margin of the rio Amazonas; and igarapé Mutum, a tributary of the rio Aruã, a tributary of rio Branco, itself tributary of the rio Arapiuns, tributary of the rio Tapajós basin (Ref. 91084). - 
Trichomycteridae Potamoglanis hasemani (Eigenmann, 1914) Fr native    1.80 cm male/unsexed  Known from the Amazon River basin (Ref. 39970). - 
Trichomycteridae Potamoglanis johnsoni (Fowler, 1932) Fr native   1.67 cm SL male/unsexed  Found in the Paraná River basin in Mato Grosso (Ref. 39970). Type locality: Descalvados, Mato Grosso, Brazil (Ref. 26282, 6868). - 
Trichomycteridae Potamoglanis wapixana (Henschel, 2016) Fr native   1.57 cm SL male/unsexed  Found in Branco and Negro river drainages, Amazonas river basin (Ref. 116786). - 
Curimatidae Potamorhina altamazonica (Cope, 1878) Fr, Fi native  Branquinha cabeça lisa (Portuguese), Mocinha (Portuguese), Mocinha do peito fino (Portuguese)   27.00 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). Found in fish markets in Santarém (Ref. 12202). + 
Curimatidae Potamorhina latior (Spix & Agassiz, 1829) Fr, Fi native  Branquinha comum (Portuguese), Branquinha (Portuguese)   24.00 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). Found in fish markets in Santarém (Ref. 12202). + 
Curimatidae Potamorhina pristigaster (Steindachner, 1876) Fr native    21.90 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). - 
Curimatidae Potamorhina squamoralevis (Braga & Azpelicueta, 1983) Fr native  Sairu-liso (Portuguese)   23.40 cm SL male/unsexed  Known from Rio Paraguay and Paraná drainage basins. - 
Belonidae Potamorrhaphis eigenmanni Miranda Ribeiro, 1915 Fr native  Peixe-agulha (Portuguese)   22.80 cm SL male/unsexed  Recorded from Machado river basin (Ref. 97589). + 
Belonidae Potamorrhaphis guianensis (Jardine, 1843) Fr native  Pirapucu (Portuguese), Peixe agulha (Portuguese)   29.10 cm TL male/unsexed  Recorded from Capim River (Ref. 50279). + 
Belonidae Potamorrhaphis labiata Sant'Anna, Delapieve & Reis, 2012 Fr native   17.49 cm OT male/unsexed  Type locality. Known from the Río Ucayali and Rio Solimões drainages in Western Amazon. - 
Belonidae Potamorrhaphis petersi Collette, 1974 Fr native  Colopétso (Portuguese), Pirapuco (Portuguese), Yavita (Portuguese)  24.60 cm SL male/unsexed  Known from Río Negro (Ref. 50279). - 
Potamotrygonidae Potamotrygon adamastor Fontenelle & Carvalho, 2017 Fr native   54.50 cm WD female  Found only in rio Urariquera, a large right-bank tributary of rio Branco, Amazon Basin, state of Roraima (Ref. 116527). - 
Potamotrygonidae Potamotrygon albimaculata Carvalho, 2016 Fr native    Known only from the rio Tapajós basin (Ref. 115937). - 
Potamotrygonidae Potamotrygon amandae Loboda & Carvalho, 2013 Fr native   31.20 cm WD male/unsexed ;34.10 cm WD female  Known from many localities throughout the Paraná-Paraguay basin: northern Pantanal, southern Pantanal, Paraná River at the border between São Paulo and Mato Grosso do Sul States, and along the border between Brazil (Paraná State) and Paraguay. Based on 2007 report, collected in the lower Tietê River (an afluent of the Paraná River in São Paulo State). Occurrence in the Tietê River is a result of the formation of the Itaipu reservoir, which previously contained the Sete Quedas waterfall system, a natural barrier impeding the presence of stingrays farther up the Paraná River (Ref. 95047). - 
Potamotrygonidae Potamotrygon amazona Fontenelle & Carvalho, 2017 Fr native   58.40 cm WD male/unsexed  Known from the rio Jutaí basin, state of Amazonas (Ref. 116527). - 
Potamotrygonidae Potamotrygon brachyura (Günther, 1880) Fr native  Arraia (Portuguese), Raia (Portuguese)  95.00 cm WD male/unsexed   - 
Potamotrygonidae Potamotrygon constellata (Vaillant, 1880) Fr, Fi native  Arraia (Portuguese), Raia (Portuguese)  62.00 cm WD male/unsexed  Reported from Santarém and from the upper Amazon (Ref. 12202). Also found in the Solimões River basin (Ref. 36687). Also Ref. 38803. + 
Potamotrygonidae Potamotrygon falkneri Castex & Maciel, 1963 Fr native  Raia (Portuguese), Arraia (Portuguese), Raya (Portuguese)   60.00 cm WD male/unsexed    + 
Potamotrygonidae Potamotrygon garmani Fontenelle & Carvalho, 2017 Fr native   42.80 cm WD female  Occurs in the middle and upper rio Tocantins basin in state of Tocantins (Ref. 116527). - 
Potamotrygonidae Potamotrygon henlei (Castelnau, 1855) Fr native  Arraia de fogo (Portuguese)  45.00 cm WD male/unsexed  Known from the Tocantins River basin in Tocantins and Araguaia rivers (Ref. 36687). Type locality, Rio Tocantins (Ref. 26282). + 
Potamotrygonidae Potamotrygon histrix (Müller & Henle, 1839) Fr, Fi native  Raia (Portuguese), Arraia (Portuguese), Arraia cocal (Portuguese), Arraia preta (Portuguese), Arraia rabo seco (Portuguese)  40.00 cm WD male/unsexed  Also Ref. 2037, 12202. + 
Potamotrygonidae Potamotrygon humerosa Garman, 1913 Fr native    Type locality, Rio Parietuba at Monte Alegre, Pará (Ref. 86697). - 
Potamotrygonidae Potamotrygon jabuti Carvalho, 2016 Fr native    Known only from Rio Tapajós basin (Ref. 115937). - 
Potamotrygonidae Potamotrygon leopoldi Castex & Castello, 1970 Fr endemic  Raia (Portuguese), Arraia (Portuguese)  111 cm WD male/unsexed  Known from the Xingu and Fresco Rivers of the Xingu River basin (Ref. 36687). Type locality, little creek on the right shore of Alto Xingú, Mato Grosso (Ref. 26282). + 
Potamotrygonidae Potamotrygon limai Fontenelle, Da Silva & Carvalho, 2014 Fr native   64.80 cm WD male/unsexed  Known from the Jamari River, upper Madeira River basin, state of Rondônia (Ref. 94972). - 
Potamotrygonidae Potamotrygon marquesi Silva & Loboda, 2019 Fr native    Type locality of Potamotrygon marquesi, Tarauacá River, Acre State, Amazon basin (Ref. 128066). - 
Potamotrygonidae Potamotrygon motoro (Müller & Henle, 1841) Fr, Fi, Or native  Arraia de fogo (Portuguese), Arraia (Portuguese), Arraia grande (Portuguese), Arraia maçã (Portuguese), Boró (Portuguese), Divevih (Portuguese), Iavevih guazú (Portuguese), Raia (Portuguese), Raia grande (Portuguese)   50.00 cm WD male/unsexed  Found in extreme western Brazil, particularly in the Yavari River, an Amazon affluent, and its tributaries, the Quixito and Itacuai (Ref. 35539). Also Ref. 38803. + 
Potamotrygonidae Potamotrygon ocellata (Engelhardt, 1912) Fr native  Raia (Portuguese), Arraia (Portuguese)  20.00 cm WD male/unsexed  Known from the Pedreira River in Amapá and south of Mexiana Island, Pará (Ref. 36687). Type locality, south of Mexiana Island at mouth of Amazon river (Ref. 36687). - 
Potamotrygonidae Potamotrygon orbignyi (Castelnau, 1855) Fr native  Arraia (Portuguese), Arraia cocal (Portuguese), Cachiva (Portuguese), Raia (Portuguese)   35.00 cm WD male/unsexed ;32.50 cm WD female  Found in the streams of the rio Machado Basin, Rondônia State (Ref. 97589). Type locality of Potamotrygon dumerilii, Rio Araguaia (Ref. 33021). + 
Potamotrygonidae Potamotrygon pantanensis Loboda & Carvalho, 2013 Fr native   26.80 cm WD male/unsexed ;33.60 cm WD female 25.5 OT Found only in the northern Pantanal region, in rivers located in Barão de Melgaço, Rosário do Oeste, and Chapada dos Guimarães, all in the state of Mato Grosso (Ref. 95047). - 
Potamotrygonidae Potamotrygon rex Carvalho, 2016 Fr native  Great freshwater stingray (English), Raia preta do Tocantins (Portuguese)  75.00 cm WD male/unsexed  Type locality of Potamotrygon rex; collected from the middle and upper rio Tocantins, from its main course and lower reaches of left and right bank affluents, and upland in the rios Paranã and Maranhão. It was also collected from lagoons marginal to the Tocantins main course (Ref. 115938). - 
Potamotrygonidae Potamotrygon schroederi Fernández-Yépez, 1958 Fr native  Raia (Portuguese), Arraia (Portuguese)  60.00 cm WD male/unsexed  Reported from Rio Negro (Ref. 36687). + 
Potamotrygonidae Potamotrygon schuhmacheri Castex, 1964 Fr native    25.00 cm WD male/unsexed   - 
Potamotrygonidae Potamotrygon scobina Garman, 1913 Fr, Fi native  Arraia (Portuguese), Raia (Portuguese)   54.70 cm WD male/unsexed  Known from the middle and lower Amazon River, lower Tocantins River, Pará River, and Trombetas River (Ref. 36687). Reported from Santarém (Ref. 12202). Type locality, Rio Tocantins at Cametá, Pará (Ref. 33021). + 
Potamotrygonidae Potamotrygon signata Garman, 1913 Fr native  Arraia (Portuguese), Arraia amarela (Portuguese), Raia (Portuguese)   30.00 cm WD male/unsexed  Known from the Parnaíba River basin (Ref. 36687). Type locality, Rio Poti, tributary of Rio Parnaíba; Parnaíba and São Gonçallo (Ref. 33021). - 
Potamotrygonidae Potamotrygon wallacei Carvalho, Rosa & Araújo, 2016 Fr native   31.00 cm WD male/unsexed  Known from Rio Negro, Amazonas (Ref. 115939). - 
Characidae Priocharax ariel Weitzman & Vari, 1987 Fr native    1.52 cm SL male/unsexed  Known from the rio Negro basin (Ref. 96862). Specimens were collected from several other localities in the Madeira system, including some of its large tributaries (e.g., Jaciparaná, Jamari, Marmelos) as well as some areas near the main channel (e.g., Lago Cuniã) (Ref. 128819). - 
Characidae Priocharax britzi Mattox, Souza, Toledo-Piza & Oliveira, 2021 Fr native   1.41 cm SL male/unsexed  Type locality of Priocharax britzi, Amazonas, Canutama, small lake approximately 400 m from the rio Ipixuna, after bridge crossing this river, on the right side of the Transamazônica Road (BR–230) going from Humaitá to Lábrea, rio Ipixuna drainage, upper Purus basin. Known only from its type locality in a marginal lake approximately 400 m from the rio Ipixuna, a tributary of the rio Purus (Ref. 124594). Status of threat: This species was found in a single location, an isolated small lake near the road, where the environmental conditions seem degraded, with depauperate riparian vegetation and silted substrate. Efforts to find specimens in the nearby rio Ipixuna and other close locations were not successful. The type locality is near a protected area (Floresta Nacional de Balata-Tufari), which was not sampled. Future studies should investigate the possibility that the species occur in other localities within the protected area and along portions of the rio Ipixuna that may connect to the lake during the wet season. There are no known imminent threats that would put the species at risk of extinction, thus, the species should be classified as Least Concern (LC) according to International Union for Conservation of Nature (IUCN) categories and criteria (IUCN Standards and Petitions Subcommittee, 2019) pending further information on its real distribution (Ref. 124594). - 
Characidae Priocharax marupiara Mattox, Britz, Souza, Casas, Lima & Oliveira, 2023 Fr native   1.72 cm SL male/unsexed  Type locality of Priocharax marupiara, Acre State, Cruzeiro do Sul municipality, Marginal pond at Igarapé Canela Fina, balneário do Canhoto on road to Guajará. Known only Igarapé Canela Fina, a small tributary of Rio Juruá, Cruzeiro do Sul municipality, Acre State (Ref. 128833. - 
Characidae Priocharax nanus Toledo-Piza, Mattox & Britz, 2014 Fr native   1.54 cm SL male/unsexed  Known from the rio Negro basin, Amazonas in the surroundings of Santa Isabel do Rio Negro (Ref. 96862). - 
Characidae Priocharax toledopizae Mattox, Britz, Souza, Casas, Lima & Oliveira, 2023 Fr native   1.88 cm SL male/unsexed  Type locality of Priocharax toledopizae, Acre State, lower Rio Moa drainage, Cruzeiro do Sul municipality, Igarapé Preto, Balneário do Zé. This species is known from several localities in the drainage of lower Rio Moa (e.g., Igarapé Preto, Igarapé Pentecostes, Lago Vermelho), a tributary of the Rio Juruá, Cruzeiro do Sul municipality, Acre State (Ref. 128833). - 
Characidae Priocharax varii Mattox, Souza, Toledo-Piza, Britz & Oliveira, 2020 Fr native   1.40 cm SL male/unsexed  Type locality of Priocharax varii, Rondônia, Candeias do Jamari, Rio Preto approximately 12 km South from road BR-364, before bridge crossing the river, Rio Jamari drainage. Known only from the type locality in the Rio Preto, a tributary of the Rio Jamari, itself an affuent of the Rio Madeira (Ref. 128819). - 
Characidae Prionobrama filigera (Cope, 1870) Fr native    6.00 cm TL male/unsexed  Found in the Acre River basin (Ref. 97592). Recorded from tributaries of Rio Jurúa (MZUSP No. 50448 (Ref. 42843). + 
Characidae Prionobrama paraguayensis (Eigenmann, 1914) Fr native   5.00 cm TL male/unsexed   + 
Characidae Pristella maxillaris (Ulrey, 1894) Fr native  Peixe raio x (Portuguese)  4.50 cm TL male/unsexed  Occurs in the Amazon (Ref. 12225). + 
Pristigasteridae Pristigaster cayana Cuvier, 1829 Fr, Br native  Apapá-verdadeiro (Portuguese), Apapá (Portuguese), Pataquera (Portuguese), Sardinha-d'água-doce (Portuguese)   14.50 cm SL male/unsexed  Known from the Amazon River basin (Ref. 50591). + 
Pristigasteridae Pristigaster whiteheadi Menezes & de Pinna, 2000 Fr native    Known from the Amazon River basin (Ref. 50591). - 
Pristidae Pristis pectinata Latham, 1794 Fr, Br, M native  Cação serra (Portuguese), Araguaguá (Portuguese), Araguaguai (Portuguese), Peixe-serra (Portuguese)  760 cm TL male/unsexed  Also Ref. 26340, 27549. + 
Pristidae Pristis perotteti Müller & Henle, 1841 Fr, Br, M, Fi native  Araguaguá (Portuguese), Espadarte (Portuguese), Peixe-serra (Portuguese), Serra (Portuguese)   650 cm TL male/unsexed  In the Amazon near Santárem. + 
Pristidae Pristis pristis (Linnaeus, 1758) Fr, Br, M native  Peixe-serra (Portuguese), Araguaguá (Portuguese), Espadarte (Portuguese)  750 cm TL male/unsexed  Recorded from the Amazon River near Manacapuru, some 80 km west of Manaus, and about 1340 km from the sea; also found in the mid-Amazon basin near Santarém (Ref. 57708). + 
Serrasalmidae Pristobrycon aureus (Spix & Agassiz, 1829) Fr native  Piranha (Portuguese)   Found in the lower portion of tributaries of the lower Amazon River (Ref. 39031). + 
Serrasalmidae Pristobrycon calmoni (Steindachner, 1908) Fr, Fi native  Piranha (Portuguese), Piranha branca (Portuguese)   15.00 cm TL male/unsexed  Occurs in the Amazon River basin (Ref. 39031). Found in fish markets in Santarém (Ref. 12202). Also Ref. 598. + 
Serrasalmidae Pristobrycon striolatus (Steindachner, 1908) Fr native  Piranha (Portuguese), Piranha mafura (Portuguese), Piranha xidowa (Portuguese)   20.10 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39031). Occurs in Para and Serra do Roncador (Ref. 12225). + 
Hypopomidae Procerusternarchus pixuna Cox Fernandes, Nogueira & Alves-Gomes, 2014 Fr native   13.82 cm TL male/unsexed  Known from the black water streams along the middle and upper portion of the Negro River Basin, Amazon (Ref. 102656). + 
Prochilodontidae Prochilodus argenteus Spix & Agassiz, 1829 Fr native  Curimatá (Portuguese), Corumbatá (Portuguese), Crumatá (Portuguese), Curim (Portuguese), Curimatã (Portuguese), Curimatá-pacú (Portuguese), Curimatã-pacu (Portuguese), Grumatá (Portuguese), Grumatão (Portuguese), Xira (Portuguese)   44.00 cm SL male/unsexed  Known only from São Francisco River basin, but introduced into various rivers of northeastern Brazil (Ref. 37057). Recorded as having been or being farmed in rice fields (Ref. 119549). Also Ref. 598. + 
Prochilodontidae Prochilodus brevis Steindachner, 1875 Fr endemic  Curimatá-comun (Portuguese), Curimatá (Portuguese), Curimatã (Portuguese), Curimatã comum (Portuguese), Curimbatá (Portuguese)   32.80 cm TL male/unsexed 22 TL Recorded from Bahia (Ref. 598). Recorded as having been or being farmed in rice fields (Ref. 119549). + 
Prochilodontidae Prochilodus britskii Castro, 1993 Fr endemic   23.80 cm SL male/unsexed  Type locality: Upriver from fall, ca. 10°36'S, 58°04'W, north of city of Juará, Rio Apiacá, Mato Grosso, MZUSP 41519 (holotype of P. britskii, 22.2 cm SL) (Ref. 27925). Also Ref. 37057. - 
Prochilodontidae Prochilodus costatus Valenciennes, 1850 Fr native  Curimatá-piao (Portuguese), Corumbatá (Portuguese), Crumatá (Portuguese), Curimatá (Portuguese), Curimatã (Portuguese), Curimatá pioa (Portuguese), Curimatã-piao (Portuguese), Curumatã (Portuguese)   42.00 cm SL male/unsexed  Originally found only in the São Francisco River basin, but reported to have been introduced into the Jequitinhonha River (Ref. 37057). + 
Prochilodontidae Prochilodus harttii Steindachner, 1875 Fr native  Curimatã (Portuguese), Grumecha (Portuguese), Gruxema (Portuguese), Papa-terra (Portuguese)   41.30 cm SL male/unsexed  Known from Pardo and Jequitinhonha River basins (Ref. 37057). Recorded from the Parahyba (Ref. 598). - 
Prochilodontidae Prochilodus lacustris Steindachner, 1907 Fr native  Curimatã (Portuguese), Curimatá (Portuguese)   34.10 cm SL male/unsexed  Known from Parnaíba and Mearim River basins (Ref. 37057). + 
Prochilodontidae Prochilodus lineatus (Valenciennes, 1837) Fr, Fi, Aq native  Corimba (Portuguese), Corimbata (Portuguese), Corimbatá (Portuguese), Corumbatá (Portuguese), Curimatã (Portuguese), Curimba (Portuguese), Curimbatá (Portuguese), Curumbatá (Portuguese), Grumatá (Portuguese), Grumatã (Portuguese), Grumatão (Portuguese) occasional (usually not seen) 80.00 cm TL male/unsexed 21.3 TL Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076) and Piracicaba river (Ref. 50076). Also reported from the Uruguay River (Ref. 79585). Also Ref. 31923. + 
Prochilodontidae Prochilodus nigricans Spix & Agassiz, 1829 Fr native  Corimatá (Portuguese), Curica (Portuguese), Curimatá (Portuguese), Curimatã (Portuguese), Curimba (Portuguese), Giriúna (Portuguese), Grumatã (Portuguese), Lambe lambe (Portuguese), Lambreta (Portuguese), Papa terra (Portuguese), Papaterra (Portuguese)   48.50 cm SL male/unsexed ;52.50 cm SL female  Found in the Amazon River and Tocantins River basin (Ref. 37057). Known from a tributary of the Madeira River, near Porto Velho (Ref. 27698). Recorded from Machado river basin (Ref. 97589). Also Ref. 598. + 
Prochilodontidae Prochilodus rubrotaeniatus Jardine, 1841 Fr native  Curimatá (Portuguese), Curimatã (Portuguese)  32.00 cm SL male/unsexed   + 
Prochilodontidae Prochilodus vimboides Kner, 1859 Fr endemic  Corimbatá (Portuguese), Corimbatá-de-lagoa (Portuguese), Curimatá (Portuguese), Curimatã (Portuguese), Curimbatá (Portuguese), Curimbatá da lagoa (Portuguese), Curimbatá de lagoa (Portuguese), Curumbatá (Portuguese), Grumecha (Portuguese), Grumexa (Portuguese), Soguaguá (Portuguese)   46.50 cm SL male/unsexed  Occurs in coastal rivers from Jequitinhonha River northwards to Paraíba River, eastern portions of upper Paraná River and São Francisco River basin.(Ref. 37057). Also Ref. 598. + 
Characidae Prodontocharax alleni Böhlke, 1953 Fr native    4.44 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37055). - 
Characidae Prodontocharax melanotus Pearson, 1924 Fr native   4.84 cm SL male/unsexed   - 
Loricariidae Proloricaria prolixa (Isbrücker & Nijssen, 1978) Fr native  Cascudo chinelo (Portuguese)   46.20 cm SL male/unsexed  Known from the upper Paraná River drainage, La Plata basin (Ref. 36389). Also Ref. 94550. + 
Pimelodidae Propimelodus araguayae Rocha, de Oliveira & Rapp Py-Daniel, 2007 Fr native   13.70 cm SL male/unsexed  Occurs only in the middle rio Araguaia in Barra do Garças, Mato Grosso State (Ref. 58940). - 
Pimelodidae Propimelodus caesius Parisi, Lundberg & DoNascimiento, 2006 Fr native    16.98 cm SL male/unsexed  Type locality, Rio Amazonas above Rio Trombetas, 20 kilometers above Obidos 1°56'07.3"S, 55°41'18.5"W, Pará State, Brazil, depth 4-7 meters (Ref. 81932). - 
Pimelodidae Propimelodus eigenmanni (Van der Stigchel, 1946) Fr native    24.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36506). - 
Rivulidae Prorivulus auriferus Costa, Lima & Suzart, 2004 Fr native     - 
Serrasalmidae Prosomyleus rhomboidalis (Cuvier, 1818) Fr native  Pacu (Portuguese), Pacu murutinga (Portuguese)  40.70 cm TL male/unsexed  Occurs in the Araguari River (Ref. 12225). + 
Characidae Protocheirodon pi (Vari, 1978) Fr native    3.10 cm SL male/unsexed    + 
Characidae Psalidodon anisitsi (Eigenmann, 1907) Fr native    13.20 cm TL male/unsexed  Recorded from the Paraguay and Uruguay basins. Also recorded from the Patos lagoon (Ref. 58359). + 
Characidae Psalidodon bifasciatus (Garavello & Sampaio, 2010) Fr native    12.92 cm SL male/unsexed  Type locality, Rio Iguaçu, marginal ponds at Avenida das Torres, at side of Reserva do Cambuí, São José dos Pinhais, Paraná, MZUSP 105961 (holotype of Astyanax bifasciatus, 8.6 cm SL, female). Known only from Rio Iguaçu where it is widely distributed (Ref. 85756). - 
Characidae Psalidodon bockmanni (Vari & Castro, 2007) Fr native    17.30 cm TL male/unsexed 3.6 TL Known from the upper Rio Paraná system of central, southeastern and southern Brazil (Ref. 57996). Type locality: Paranaíba River, near the southern headwaters of the north-flowing Tocantins basin (Ref. 80770). + 
Characidae Psalidodon dissensus (Lucena & Thofehrn, 2013) Fr native   12.40 cm TL male/unsexed  Known from the Laguna dos Patos system and rio Uruguay drainage. Also recorded from coastal lagoon of rio Tramandaí system based on one specimen (Ref. 94153). - 
Characidae Psalidodon eigenmanniorum (Cope, 1894) Fr native  Lambari (Portuguese), Piaba (Portuguese), Piaba do Rio Grande do Sul (Portuguese)   14.40 cm TL male/unsexed  Recorded from the Patos lagoon (Ref. 58359). Museum: Rio Grande do Sul, ANSP 21627-28 (2 paratypes, 4.25-49.4 cm SL) (Ref. 46822). - 
Characidae Psalidodon fasciatus (Cuvier, 1819) Fr native  Lambari (Portuguese), Lambari de rabo vermelho (Portuguese), Lambari do rabo vermelho (Portuguese), Piaba Alto Amazonas (Portuguese), Piaba da Bahia (Portuguese), Piaba-rabo-vermelho (Portuguese)   17.10 cm TL male/unsexed 7.64 SL Occurs in the Pardo River, upper Paraná River basin, southeastern Brazil (Ref. 27745). Also recorded from the Patos lagoon (Ref. 58359) and the Uruguay River (Ref. 79585). Also Ref. 53011. + 
Characidae Psalidodon gymnodontus Eigenmann, 1911 Fr endemic  Lambari (Portuguese)   17.00 cm SL male/unsexed  Known only from the Iguaçu River basin in southern Brazil (Ref. 86650). Also Ref. 598, 38376. - 
Characidae Psalidodon gymnogenys (Eigenmann, 1911) Fr native  Lambari (Portuguese), Lambari do rabo amarelo (Portuguese)   11.52 cm SL male/unsexed  Found in the Iguaçu River basin (Ref. 38376). - 
Characidae Psalidodon marionae (Eigenmann, 1911) Fr native  Lambari (Portuguese)  9.10 cm SL male/unsexed  Recorded from the upper Paraguay river. - 
Characidae Psalidodon parahybae (Eigenmann, 1908) Fr native  Lambari (Portuguese)   16.90 cm TL male/unsexed  Recorded from the Paraibuna and Paraitinga rivers (Ref. 85129). + 
Characidae Psalidodon paranae (Eigenmann, 1914) Fr native  Alambari (Portuguese), Lambari (Portuguese)   16.40 cm TL male/unsexed 3.25 SL Collected from rio Tietê basin in São Paulo State and rio Iguaçu basin from Paraná State (Ref. 81202). Recorded from rio Pitangui, upper rio Paraná basin (Ref. 81203). + 
Characidae Psalidodon pellegrini (Eigenmann, 1907) Fr native  Lambari (Portuguese)  8.00 cm SL male/unsexed   - 
Characidae Psalidodon rivularis (Lütken, 1875) Fr native  Piaba (Portuguese)  9.91 cm SL male/unsexed  Found in the São Francisco River basin (Ref. 38376). + 
Characidae Psalidodon schubarti (Britski, 1964) Fr, Fi native  Lambari (Portuguese), Lambari de rabo amarelo (Portuguese)   9.00 cm SL male/unsexed 5.6 TL Known from the upper Paraná (Ref. 38376) and Piracicaba river (Ref. 50076). Museum: Rio Mogi Guassu, Emas, Sao Paulo, DZ 4263 (holotype of A. schubarti, 8.3 cm SL) (Ref. 27925). Also Ref. 31923. + 
Characidae Psalidodon xavante (Garutti & Venere, 2009) Fr native   5.96 cm SL male/unsexed 2.6 SL Occurs in córrego Avoadeira, a tributary of the middle rio Araguaia situated in the Parque Estadual da Serra Azul, Barra do Garças, Mato Grosso. More abundant in the upper and middle courses of the córrego Avoadeira. The number of individuals decreases downstream (Ref. 82392). + 
Characidae Psalidodon xiru (Lucena, Castro & Bertaco, 2013) Fr native   10.93 cm SL male/unsexed  Known from the rio Jacuí drainage, laguna dos Patos system, and from the upper rio Uruguay drainage, Rio Grande do Sul, and Santa Catarina States (Ref. 94153). - 
Curimatidae Psectrogaster amazonica Eigenmann & Eigenmann, 1889 Fr, Fi native  Cascudinha (Portuguese), Branquinha cascuda (Portuguese), Branquinha comun (Portuguese), Casca grossa (Portuguese), Chico-duro (Portuguese)   19.00 cm SL male/unsexed  Known from Tocantins and Amazon River basins (Ref. 38013). Found in fish markets in Santarém (Ref. 12202). Type locality, Lago Aleixo, on Rio Negro, Amazonas (Ref. 34107). + 
Curimatidae Psectrogaster ciliata (Müller & Troschel, 1844) Fr native  Beiru (Portuguese), Branquinha (Portuguese)  12.90 cm SL male/unsexed  Recorded from the Rio Branco and Rio Negro systems in the Amazon basin (Ref. 34107). - 
Curimatidae Psectrogaster curviventris Eigenmann & Kennedy, 1903 Fr native  Sairu-cascudo (Portuguese)   17.10 cm SL male/unsexed    - 
Curimatidae Psectrogaster essequibensis (Günther, 1864) Fr native    16.90 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). + 
Curimatidae Psectrogaster falcata (Eigenmann & Eigenmann, 1889) Fr native   25.60 cm TL male/unsexed  Known from the lower portions of the Amazon River (Ref. 38013). Also Ref. 27116. - 
Curimatidae Psectrogaster rhomboides Eigenmann & Eigenmann, 1889 Fr native  Beru (Portuguese), Branquinho (Portuguese), Coró (Portuguese), Coró branco (Portuguese), Peixe branco (Portuguese)   17.80 cm SL male/unsexed  Known from Parnaíba and Jaguaribe River basins (Ref. 38013). + 
Curimatidae Psectrogaster rutiloides (Kner, 1858) Fr, Fi native  Branquinha cascuda (Portuguese), Casca grossa roliça (Portuguese)   17.80 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). Found in fish markets in Santarém (Ref. 12202). Type locality: Matto Grosso, Barra do Rio Negro (Ref. 34107). + 
Curimatidae Psectrogaster saguiru (Fowler, 1941) Fr native   16.40 cm SL male/unsexed  Found in northeastern Brazil (Ref. 38013). Type locality, Lago Papary, Rio Grande do Norte (Ref. 26282). - 
Characidae Psellogrammus kennedyi (Eigenmann, 1903) Fr native  Lambari (Portuguese), Piaba (Portuguese), Piabinha (Portuguese)   5.90 cm SL male/unsexed  Also Ref. 598. + 
Loricariidae Pseudacanthicus histrix (Valenciennes, 1840) Fr native  Uacari-guassú (Portuguese), Guacari açu (Portuguese), Guacarí açu (Portuguese), Uacari (Portuguese), Uacari açu (Portuguese), Uacari guaçu (Portuguese)   90.00 cm TL male/unsexed  Known from Negro and lower Amazon River basins (Ref. 36713). + 
Loricariidae Pseudacanthicus pirarara Chamon & Sousa, 2016 Fr native   40.50 cm TL male/unsexed   + 
Loricariidae Pseudacanthicus pitanga Chamon, 2015 Fr native   30.00 cm SL male/unsexed  Type locality of Pseudacanthicus pitanga, Serra dos Carajás, bedrock at rio Itacaiunas, Serra dos Carajás, Pará. Recorded in the lower Tocantins river basin, at Serra dos Carajás, Tucuruí and Cametá, Pará state, and median Tocantins river basin, between São Salvador and Lajeado, Tocantins state (Ref. 102632). - 
Loricariidae Pseudacanthicus spinosus (Castelnau, 1855) Fr endemic  Acari (Portuguese), Acarí (Portuguese), Acarí pirarara (Portuguese), Bodó (Portuguese)   26.00 cm SL male/unsexed  Known from Amazon River basin (Ref. 36713). + 
Loricariidae Pseudancistrus asurini Silva, Roxo & Oliveira, 2015 Fr native   25.10 cm TL male/unsexed  Found in rio Xingu, municipality of Altamira, from the Xingu river basin, Pará State (Ref. 99871). + 
Loricariidae Pseudancistrus barbatus (Valenciennes, 1840) Fr native  Acari (Portuguese)  20.00 cm SL male/unsexed  Known from Rio Tapajós at Vila Braga (Ref. 6868). + 
Loricariidae Pseudancistrus genisetiger Fowler, 1941 Fr native   10.30 cm SL male/unsexed  Known from the Jaguaribe River basin (Ref. 36713). - 
Loricariidae Pseudancistrus kayabi Silva, Roxo & Oliveira, 2015 Fr native   8.84 cm SL male/unsexed  Known from rio Teles Pires, rio Tapajós basin in municipality of Itaúba and Paranaíta, Mato Grosso State (Ref. 99871). - 
Loricariidae Pseudancistrus papariae Fowler, 1941 Fr endemic   15.30 cm SL male/unsexed  Known from Lake Papari and Jaguaribe River basin (Ref. 36713). - 
Loricariidae Pseudancistrus zawadzkii Silva, Roxo, Britzke & Oliveira, 2014 Fr native   11.64 cm SL male/unsexed ;12.87 cm SL female  Found in the rio Tapajós and rio Tracuá, municipality of Itaituba, all from rio Tapajós basin, Pará State (Ref. 95679). - 
Anostomidae Pseudanos gracilis (Kner, 1858) Fr native    18.11 cm SL male/unsexed  Known from Guaporé and Negro River basins (Ref. 36801), and Madeira River (Ref. 91907). Also Ref. 598, 91907. + 
Anostomidae Pseudanos trimaculatus (Kner, 1858) Fr native  Uaracu (Portuguese)   18.80 cm TL male/unsexed  Known from the Amazon River (Ref. 36801). + 
Anostomidae Pseudanos varii Birindelli, Lima & Britski, 2012 Fr native   21.00 cm SL male/unsexed  Known throughout the Rio Negro basin (Ref. 91907). - 
Anostomidae Pseudanos winterbottomi Sidlauskas & Santos, 2005 Fr native   15.17 cm SL male/unsexed  Known from Rio Tapajos drainage (Ref. 55429). + 
Auchenipteridae Pseudauchenipterus affinis (Steindachner, 1877) Fr native    12.00 cm SL male/unsexed  Found in Rio São Mateus and Rio Mucuri, Porto Alegre (Ref. 6868). - 
Auchenipteridae Pseudauchenipterus flavescens (Eigenmann & Eigenmann, 1888) Fr native  Bagre (Portuguese), Peixe-gato (Portuguese)   Occurs in São Francisco River basin (Ref. 37098). Also Ref. 6868. - 
Auchenipteridae Pseudauchenipterus jequitinhonhae (Steindachner, 1877) Fr native    11.00 cm SL male/unsexed  Found in the Jequitinhonha River basin (Ref. 6868, 37098). - 
Auchenipteridae Pseudauchenipterus nodosus (Bloch, 1794) Fr, Br native  Carataí (Portuguese), Caratahy (Portuguese), Caravataí (Portuguese), Papista (Portuguese), Peixe cachorro (Portuguese), Peixe-gato (Portuguese), Pirá-andirá (Portuguese)   22.00 cm SL male/unsexed    + 
Auchenipteridae Pseudepapterus cucuhyensis Böhlke, 1951 Fr native   5.90 cm SL male/unsexed  Known from the Amazon and Negro River basins (Ref. 37098). Found in Cucuhy on the Colombian border, Rio Negro (Ref. 6868). - 
Auchenipteridae Pseudepapterus hasemani (Steindachner, 1915) Fr native    9.90 cm SL male/unsexed  Known from the Amazon and Tocantins River basins (Ref. 37098). Found in Pará (Ref. 6868). - 
Aspredinidae Pseudobunocephalus amazonicus (Mees, 1989) Fr native    4.50 cm SL male/unsexed  Known from the Amazon River (Ref. 36695) and Machado River basins (Ref. 97589). + 
Aspredinidae Pseudobunocephalus bifidus (Eigenmann, 1942) Fr native    4.30 cm SL male/unsexed  nown from the Amazon River basin (Ref. 36695). - 
Aspredinidae Pseudobunocephalus iheringii (Boulenger, 1891) Fr native   6.30 cm TL male/unsexed   - 
Aspredinidae Pseudobunocephalus rugosus (Eigenmann & Kennedy, 1903) Fr native    3.00 cm SL male/unsexed  Also Ref. 36695. - 
Aspredinidae Pseudobunocephalus timbira Leão, Carvalho, Reis & Wosiacki, 2019 Fr endemic   3.18 cm SL male/unsexed  Type locality of Pseudobunocephalus timbira: Jundiá Creek, Mearim River basin, Maranhão (Ref. 120442). - 
Characidae Pseudocorynopoma doriae Perugia, 1891 Fr native  Lambari-bandeira (Portuguese), Lambari (Portuguese)  6.30 cm SL male/unsexed   + 
Characidae Pseudocorynopoma heterandria Eigenmann, 1914 Fr native   5.62 cm SL male/unsexed  Type locality of Pseudocorynopoma heterandria, Xiririca, Rio Ribeira, São Paulo (Ref. 33021). Found in coastal clearwater rivers in São Paulo and Paraná (Ref. 38597). Recorded from the rio Paraitinga, tributary to the rio Tietê, near Salesópolis (Ref. 34079). + 
Characidae Pseudocorynopoma stanleyi Malabarba, Chuctaya, Hirschmann, Oliveira & Thomaz, 2020 Fr native   6.22 cm SL male/unsexed ;6.05 cm SL female  Type locality of Pseudocorynopoma stanleyi, Rio Grande do Sul, Marques de Souza, Arroio Tamanduá, Linha Tamanduá (Ref. 123882). + 
Loricariidae Pseudohemiodon amazonum (Delsman, 1941) Fr native   9.20 cm SL male/unsexed  Found in the Amazon River basin (Ref. 36389). - 
Loricariidae Pseudohemiodon laticeps (Regan, 1904) Fr native   29.80 cm SL male/unsexed   + 
Loricariidae Pseudohemiodon platycephalus (Kner, 1853) Fr native   18.00 cm SL male/unsexed  Found in the Paraguay River basin (Ref. 36389). - 
Loricariidae Pseudolithoxus kinja Bifi, de Oliveira, Rapp Py-Daniel & Collins, 2018 Fr, Or native   15.31 cm SL male/unsexed  Type locality of Pseudolithoxus kinja, Brazil, Amazonas, São Sebastião do Uatumã, rio Uatumã, Santa Luzia de Jacarequara. It is currently known from three clearwater rivers of the Brazilian and Guiana shields in Amazonas State: rio Uatumã, rio Nhamunda and rio Guariba (rio Madeira-Aripuanã drainage). It has been reported in the aquarium trade literature under the tag names Pseudolithoxus sp. ‘L385’ and Pseudolithoxus sp. ‘L492, fishes supposedly from the rio Trombetas and the rio Jauaperi, respectively (Ref. 119352).

Conservation status: It has been estimated that this species has lost ca. 25% of its historical distribution due to impoundment of the rio Uatumã by the Balbina Dam. The rio Pitinga, despite the water-control regime, still has this species. No appreciable threat to the quality of its natural habitat appears to exist on the rio Nhamunda and rio Guariba, but the extent of distribution in these rivers remains unclear (collections were only made from single locations). Thus, the authors suggest that P. kinja be classified as LC (Least Concern) under the IUCN criteria of evaluation of conservation status (IUCN, 2012) (Ref. 119352). 

- 
Loricariidae Pseudoloricaria laeviuscula (Valenciennes, 1840) Fr native  Uacari (Portuguese)  36.00 cm SL male/unsexed  Known from the lower and middle Amazon basin, including Negro and Branco rivers (Ref. 36389). + 
Syngnathidae Pseudophallus mindii (Meek & Hildebrand, 1923) Fr native  Peixe-cachimbo (Portuguese)   16.00 cm SL male/unsexed    + 
Pseudopimelodidae Pseudopimelodus bufonius (Valenciennes, 1840) Fr native  Bagre sapo (Portuguese), Jaú sapo (Portuguese)   24.50 cm SL male/unsexed  Found in the Acre and Purus River basins (Ref. 97592). + 
Pseudopimelodidae Pseudopimelodus charus (Valenciennes, 1840) Fr endemic  Peixe-sapo (Portuguese)  20.20 cm SL male/unsexed  Known from São Francisco River basin (Ref. 39418). - 
Pseudopimelodidae Pseudopimelodus mangurus (Valenciennes, 1835) Fr, Fi, Aq native  Piracururu (Portuguese), Bagre-sapo (Portuguese), Brecumbucu (Portuguese), Jaú sapo (Portuguese), Manguriú (Portuguese), Pacamá (Portuguese), Pacamã (Portuguese), Pacamão (Portuguese), Peixe sapo (Portuguese), Piacoruru (Portuguese), Pirá cururu (Portuguese)   69.00 cm TL male/unsexed  Found in the Uruguay River (Ref. 79585). Also Ref. 39418. + 
Pseudopimelodidae Pseudopimelodus pulcher (Boulenger, 1887) Fr native   19.50 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39418). - 
Pimelodidae Pseudoplatystoma corruscans (Spix & Agassiz, 1829) Fr, Fi, Aq, Sp, Thr native  Pintado (Portuguese), Bagre rajado (Portuguese), Caçonete (Portuguese), Cambucu (Portuguese), Caparari (Portuguese), Loango (Portuguese), Moleque (Portuguese), Piracajiara (Portuguese), Sorubí (Portuguese), Sorubim (Portuguese), Surubi de cama (Portuguese), Surubim (Portuguese), Surubim-pintado (Portuguese)   182 cm TL male/unsexed 51 TL Known from São Francisco River basin (Ref. 36506). Reported from the Uruguay River (Ref. 79585). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 31923. + 
Pimelodidae Pseudoplatystoma fasciatum (Linnaeus, 1766) Fr, Fi native  Pintado (Portuguese), Cachara (Portuguese), Cacharra (Portuguese), Cachorra (Portuguese), Piracambucu (Portuguese), Pirambucu (Portuguese), Pirapará (Portuguese), Pirarcachiára (Portuguese), Sorubi (Portuguese), Sorubim (Portuguese), Surubi (Portuguese), Surubim (Portuguese), Surubim lenha (Portuguese), Surubim pintado (Portuguese), Surubim rajado (Portuguese), Surubim tora (Portuguese), Surubim-cachara (Portuguese), Surumbi (Portuguese), Surumi (Portuguese)   105 cm SL male/unsexed  Found in the Rio Madeira and Rio Machado. Migrates upstream in the Rio Madeira during low water periods (Ref. 6868). + 
Pimelodidae Pseudoplatystoma reticulatum Eigenmann & Eigenmann, 1889 Fr native    60.50 cm SL male/unsexed    + 
Pimelodidae Pseudoplatystoma tigrinum (Valenciennes, 1840) Fr, Sp native  Capari (Portuguese), Cabezona (Portuguese), Caparari (Portuguese), Pintado (Portuguese), Pirambucu (Portuguese), Sorubim (Portuguese), Sorubim tigre (Portuguese), Surubim tigre (Portuguese)   130 cm TL male/unsexed  Utilized as a game fish (Ref. 6323). + 
Loricariidae Pseudorinelepis genibarbis (Valenciennes, 1840) Fr native    35.60 cm SL male/unsexed  Known from the Amazon River and its major tributaries (Rios Madeira and Negro). Also Ref. 6868, 36817, 43112. + 
Trichomycteridae Pseudostegophilus nemurus (Günther, 1869) Fr native    15.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39970). + 
Auchenipteridae Pseudotatia parva Mees, 1974 Fr native   4.60 cm SL male/unsexed  Known from São Francisco River basin (Ref. 37098). Found in Joazeiro (=Juàzeiro) (Ref. 6868). - 
Loricariidae Pseudotocinclus juquiae Takako, Oliveira & Oyakawa, 2005 Fr native   3.19 cm SL male/unsexed  Known from Ribeira de Iguape basin (Ref. 56904). - 
Loricariidae Pseudotocinclus parahybae Takako, Oliveira & Oyakawa, 2005 Fr native    Known from Rio Paraiba do Sul basin (Ref. 56904). - 
Loricariidae Pseudotocinclus tietensis (Ihering, 1907) Fr endemic  Cascudinho (Portuguese)   6.23 cm SL male/unsexed  Endemic to the headwaters of the Tietê river at Paranapiacaba, Sao Paulo. - 
Loricariidae Pseudotothyris ignota Martins, Britski & Langeani, 2014 Fr native   3.30 cm SL male/unsexed  Occurs in Coastal drainages from Iguape in São Paulo state to São João do Rio Vermelho in Santa Catarina state (Ref. 116384). - 
Loricariidae Pseudotothyris janeirensis Britski & Garavello, 1984 Fr native   5.00 cm SL male/unsexed  Found only in coastal drainages in Rio de Janeiro state, from Engenheiro Paulo de Frontin to Macaé (Ref. 116384). - 
Loricariidae Pseudotothyris obtusa (Miranda Ribeiro, 1911) Fr native    4.00 cm SL male/unsexed  Found in coastal drainages from São Sebastião in São Paulo state to Ilha do Superagüi, Baia de Paranaguá, in Paraná state (Ref. 116384). Also Ref. 6868. - 
Belonidae Pseudotylosurus angusticeps (Günther, 1866) Fr native    29.80 cm SL male/unsexed  Known from the Paranà, Paraguay (Ref. 50279) and Acre River basins (Ref. 97592). + 
Belonidae Pseudotylosurus microps (Günther, 1866) Fr native    44.00 cm TL male/unsexed    + 
Engraulidae Pterengraulis atherinoides (Linnaeus, 1766) Fr, Br, Fi native  Sardinha (Portuguese), Maiacá (Portuguese), Manjuba (Portuguese), Sardinha de gato (Portuguese), Sardinha de lata (Portuguese), Sardinha-do-gato (Portuguese), Tubaraninha (Portuguese)   30.00 cm TL male/unsexed  Important in the artisanal fisheries in the region of Belem (Ref. 189). Also Ref. 5217. + 
Aspredinidae Pterobunocephalus depressus (Haseman, 1911) Fr native    8.90 cm SL male/unsexed    + 
Aspredinidae Pterobunocephalus dolichurus (Delsman, 1941) Fr native   7.33 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36695). + 
Doradidae Pterodoras granulosus (Valenciennes, 1821) Fr native  Abotoado (Portuguese), Bacu barriga mole (Portuguese), Armado (Portuguese), Armado comum (Portuguese), Armau (Portuguese), Bacu (Portuguese), Bacu liso (Portuguese), Bacu pedra (Portuguese), Barriga-de-folha (Portuguese), Botoado (Portuguese), Botoado barriga de folha (Portuguese), Cuiú cuiú (Portuguese), Cuiú cuiú preto (Portuguese), Vacu pedra (Portuguese)   68.00 cm SL male/unsexed ;90.10 cm SL female 24.2 TL   + 
Rivulidae Pterolebias longipinnis Garman, 1895 Fr native    12.00 cm TL male/unsexed  Known from the Amazon and Paraguay River basins (Ref. 36579). Museum: Rio Guajará-Mirim, Guaporé, MNRJ 8672 (Ref. 36579). Also Ref. 27139. + 
Rivulidae Pterolebias phasianus Costa, 1988 Fr native   7.00 cm TL male/unsexed  Known from the Paraguay River (Ref. 36579). Also Ref. 27139. + 
Cichlidae Pterophyllum leopoldi (Gosse, 1963) Fr native    5.00 cm SL male/unsexed  Known from the Amazon River basin along the Solimões-Amazon River between about Manacapuru and Santarém (Ref. 36377). Type locality: Furo du village de Cuia, left bank of Rio Solimôes, ca. 90 km upstreams of the Manacapuru, Brazil (Ref. 26282). + 
Cichlidae Pterophyllum scalare (Schultze, 1823) Fr native  Cara bandeira (Portuguese), Acará bandeira (Portuguese), Buxuari (Portuguese), Charéu (Portuguese), Escalare (Portuguese), Piraque (Portuguese)   10.50 cm TL male/unsexed  Known from the Amazon River basin and rivers of Amapá (Ref. 36377). + 
Loricariidae Pterosturisoma microps (Eigenmann & Allen, 1942) Fr native    16.10 cm SL male/unsexed    + 
Loricariidae Pterygoplichthys ambrosettii (Holmberg, 1893) Fr native  Cascudo (Portuguese)   54.90 cm TL male/unsexed ;55.00 cm TL female 24.1 TL  + 
Loricariidae Pterygoplichthys disjunctivus (Weber, 1991) Fr native   70.00 cm TL male/unsexed  Type locality: Rio Madeira, Amazon R. system, Restauracao, Amazonas, Brazil (Ref. 26282). + 
Loricariidae Pterygoplichthys etentaculatus (Spix & Agassiz, 1829) Fr, Fi native  Cascudo (Portuguese), Acari amarelo (Portuguese), Acarí amarelo (Portuguese), Acarí juba (Portuguese), Acarí roncador (Portuguese), Acarijuba (Portuguese), Carinhanha (Portuguese), Cascudo amarelo (Portuguese), Coroncho (Portuguese), Guacarí (Portuguese), Panaque (Portuguese)  30.00 cm SL male/unsexed  Type locality: Rio São Francisco, Januaria, Minas Gerais, Brazil (Ref. 26282). + 
Loricariidae Pterygoplichthys gibbiceps (Kner, 1854) Fr, Or native  Bode cacunda (Portuguese)   50.00 cm TL male/unsexed  Occurs in Rio Negro northwest Brazil (Ref. 4537). Exported to North America as an aquarium fish (Ref. 4537). + 
Loricariidae Pterygoplichthys joselimaianus (Weber, 1991) Fr native  Acari bodó (Portuguese)   39.50 cm SL male/unsexed  Known from the Rio Tocantins drainage (Ref. 26660). + 
Loricariidae Pterygoplichthys lituratus (Kner, 1854) Fr native  Boi de carro (Portuguese), Cari (Portuguese), Cari laranja (Portuguese)   37.00 cm SL male/unsexed  Known from the Rio Madeira drainage of the Rio Amazonas basin (Ref. 26660). - 
Loricariidae Pterygoplichthys multiradiatus (Hancock, 1828) Fr native  Acari (Portuguese), Bajurqui (Portuguese), Bodó (Portuguese), Cascudo (Portuguese)   50.00 cm TL male/unsexed   + 
Loricariidae Pterygoplichthys pardalis (Castelnau, 1855) Fr, Fi native  Acari bodó bodó (Portuguese), Acari (Portuguese), Acarí (Portuguese), Bode casa velha (Portuguese)   57.80 cm TL male/unsexed  Type locality: Amazon. Found in fish markets in Santarém (Ref. 12202). + 
Loricariidae Pterygoplichthys parnaibae (Weber, 1991) Fr native    29.00 cm SL male/unsexed  Known from the Rio Parnaíba drainage (Ref. 26660). + 
Loricariidae Pterygoplichthys punctatus (Kner, 1854) Fr native  Bode de igapó (Portuguese)   28.50 cm SL male/unsexed  Known from rio Madeira drainage and the rio Urubu, with unconfirmed identity of specimens taken from rio Purus and the rio Tocantins (Ref. 75871). Also reported from Acre River basin (Ref. 97592). + 
Loricariidae Pterygoplichthys xinguensis (Weber, 1991) Fr native   37.50 cm TL male/unsexed  Known from the Rio Xingu drainage of the Rio Amazonas basin (Ref. 26660). - 
Trichomycteridae Pygidianops amphioxus de Pinna & Kirovsky, 2011 Fr native   3.04 cm SL male/unsexed ;2.57 cm SL female   - 
Trichomycteridae Pygidianops eigenmanni Myers, 1944 Fr native   2.30 cm SL male/unsexed  Known from the Negro River basin (Ref. 39970). Type locality: Rock pools below Sao Gabriel Rapids, Rio Negro, Brazil (Ref. 26282, 6868). - 
Serrasalmidae Pygocentrus nattereri Kner, 1858 Fr, Fi native  Piranha vermelha (Portuguese), Piranha (Portuguese), Piranha caju (Portuguese), Piranha-quexicuda (Portuguese)   50.00 cm SL male/unsexed  Occurs in the lower Oyapock, border to French Guiana (Ref. 35237). Reported from the Uruguay River (Ref. 79585). Found in fish markets in Santarém (Ref. 12202). Also Ref. 39031. + 
Serrasalmidae Pygocentrus piraya (Cuvier, 1819) Fr, Fi, Or, Sp endemic  Piranha (Portuguese), Chupita (Portuguese), Piranha amarela (Portuguese), Piranha rodoleira (Portuguese)   34.00 cm SL male/unsexed  Known from Sao Francisco River basin (Ref. 39031). Exported to North America as an aquarium fish (Ref. 4537). + 
Serrasalmidae Pygopristis denticulata (Cuvier, 1819) Fr, Fi native  Piranha (Portuguese), Piranha mapará (Portuguese)   21.50 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39031). Recorded from the Rio Tocantin (Ref. 12225). Also Ref. 12225. + 
Lebiasinidae Pyrrhulina australis Eigenmann & Kennedy, 1903 Fr native    5.00 cm SL male/unsexed 2 TL Found in Pantanal (Ref. 81048). Also Ref. 37104. + 
Lebiasinidae Pyrrhulina beni Pearson, 1924 Fr native   5.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). - 
Lebiasinidae Pyrrhulina brevis Steindachner, 1876 Fr native   7.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Lebiasinidae Pyrrhulina elongata Zarske & Géry, 2001 Fr native   3.70 cm SL male/unsexed  Type locality: Brazil, Para, creek and small pond about 25 km southwest of Itaituba near the road Itaituba - Villa Nova, basin of Rio Tapajós. - 
Lebiasinidae Pyrrhulina filamentosa Valenciennes, 1847 Fr native  Pirá-tan-tan (Creole, Portuguese)  11.10 cm SL male/unsexed  Amazonia. + 
Lebiasinidae Pyrrhulina laeta (Cope, 1872) Fr questionable   7.60 cm SL male/unsexed   + 
Lebiasinidae Pyrrhulina marilynae Netto-Ferreira & Marinho, 2013 Fr native   3.00 cm SL male/unsexed   - 
Lebiasinidae Pyrrhulina maxima Eigenmann & Eigenmann, 1889 Fr native   8.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). Type locality, Rio Solimões at Tabatinga, Amazon system (Ref. 26282). - 
Lebiasinidae Pyrrhulina melanostomus (Cope, 1870) Fr, Fi native     - 
Lebiasinidae Pyrrhulina obermulleri Myers, 1926 Fr native    6.00 cm SL male/unsexed  Found in Purus and Acre River basins (Ref. 97592). + 
Lebiasinidae Pyrrhulina rachoviana Myers, 1926 Fr, Fi native    3.90 cm SL male/unsexed    + 
Lebiasinidae Pyrrhulina semifasciata Steindachner, 1876 Fr native   7.00 cm SL male/unsexed  Museum: MZUSP uncat., (57.5 mm SL). + 
Lebiasinidae Pyrrhulina vittata Regan, 1912 Fr, Fi native    3.50 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Lebiasinidae Pyrrhulina zigzag Zarske & Géry, 1997 Fr native   3.50 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37104). + 
Loricariidae Pyxiloricaria menezesi Isbrücker & Nijssen, 1984 Fr native   14.00 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 36389). + 
Characidae Rachoviscus crassiceps Myers, 1926 Fr native    3.85 cm SL male/unsexed  Known from Rio de Janeiro (Ref. 598). + 
Characidae Rachoviscus graciliceps Weitzman & Cruz, 1981 Fr native    4.76 cm SL male/unsexed  Museum: about 1 km N Prado, about 500 m from Atlantic Ocean, Bahia, MZUSP 14387 (holotype of R. graciliceps, 4.44 cm SL) (Ref. 27925). Also Ref. 38376. + 
Loricariidae Reganella depressa (Kner, 1853) Fr native   11.30 cm SL male/unsexed  Found in Negro, Branco and Tapajós River basins (Ref. 36389). + 
Cichlidae Retroculus lapidifer (Castelnau, 1855) Fr endemic  Ajunta pedra (Portuguese), Cará bico doce (Portuguese), Cará de pedra (Portuguese), Cará pedral (Portuguese), Cará-bicudo (Portuguese)   19.50 cm SL male/unsexed ;25.10 cm SL female  Known from the Amazon River basin in the Tocantins and Capim River basins (Ref. 36377). Also found in the Rio Araguaia (Ref. 37197). + 
Cichlidae Retroculus septentrionalis Gosse, 1971 Fr native  Cara bicudo (Portuguese)   19.00 cm SL male/unsexed  Known from Oyapock River and Araguari River drainages (Ref. 36377). - 
Cichlidae Retroculus xinguensis Gosse, 1971 Fr endemic    31.00 cm TL male/unsexed  Known from the Amazon River basin, in the Xingu and Tapajós River basins (Ref. 36377). Type locality: Rio Xingu, at Cachoeira von Martius, n. border of Mato Grosso, Brazil (Ref. 12965). + 
Sternopygidae Rhabdolichops caviceps (Fernández-Yépez, 1968) Fr native   31.00 cm TL male/unsexed   - 
Sternopygidae Rhabdolichops eastwardi Lundberg & Mago-Leccia, 1986 Fr native    27.60 cm TL male/unsexed    - 
Sternopygidae Rhabdolichops electrogrammus Lundberg & Mago-Leccia, 1986 Fr native    29.20 cm TL male/unsexed  Recorded from Rios Negro and Branco (Ref. 9394). - 
Sternopygidae Rhabdolichops lundbergi Correa, Crampton & Albert, 2006 Fr native   24.10 cm TL male/unsexed ;17.50 cm TL female  Known from the Amazon basin (Ref. 55969). - 
Sternopygidae Rhabdolichops navalha Correa, Crampton & Albert, 2006 Fr native   16.10 cm SL male/unsexed  Known from the Amazon basin (Ref. 55969). - 
Sternopygidae Rhabdolichops nigrimans Correa, Crampton & Albert, 2006 Fr native   43.10 cm TL male/unsexed ;30.50 cm TL female  Known from the type locality, Rio Tefe, and from the lower Rio Negro, Amazon basin (Ref. 55969). - 
Sternopygidae Rhabdolichops stewarti Lundberg & Mago-Leccia, 1986 Fr native   20.70 cm TL male/unsexed  Recorded from RioTapajos (Ref. 9394). Also Ref. 26457. - 
Sternopygidae Rhabdolichops troscheli (Kaup, 1856) Fr native    49.00 cm TL male/unsexed  Found in the Amazon River (Ref. 39524). Also Ref. 26457. - 
Loricariidae Rhadinoloricaria laani (Nijssen & Isbrücker, 1988) Fr native    13.00 cm SL male/unsexed    - 
Loricariidae Rhadinoloricaria ommation (Nijssen & Isbrücker, 1988) Fr native    9.80 cm SL male/unsexed   - 
Loricariidae Rhadinoloricaria papillosa Crispim-Rodrigues, Bernt, Waltz, Silva, Benine, Oliveira, Covain & Roxo, 2023 Fr native   7.39 cm SL female  Type locality of Rhadinoloricaria papillosa, Amazonas State, municipality of Barcelos, Rio Amazonas basin, Rio Negro, Rio Demeni. Occurs at the bottom of Rio Negro, between the states of Amazonas and Pará (Ref. 128857). - 
Heptapteridae Rhamdella eriarcha (Eigenmann & Eigenmann, 1888) Fr endemic  Mandi (Portuguese)  20.90 cm SL male/unsexed  Known from Jacuí River basin (Ref. 36914). Type locality: Rio Grande do Sul, Brazil (Ref. 26282, 6868). - 
Heptapteridae Rhamdella exsudans (Jenyns, 1842) Fr endemic   8.90 cm TL male/unsexed  Known from Rio de Janeiro (Ref. 6868, 36914). - 
Heptapteridae Rhamdella jenynsii (Günther, 1864) Fr native   8.90 cm TL male/unsexed  Type locality: Rio de Janeiro, Brazil (Ref.6868, 36914). - 
Heptapteridae Rhamdella longiuscula Lucena & da Silva, 1991 Fr endemic  Mandi (Portuguese)  22.00 cm TL male/unsexed  Known from the middle Uruguay River basin (Ref. 36914). Type locality: Arroio Passo do Alto, near Mineral, Sao Nicolau, ca. 28°08'S, 55°20'W, Rio Grande do Sul, Brazil. + 
Heptapteridae Rhamdella zelimai Reis, Malabarba & Lucena, 2014 Fr native   13.60 cm SL male/unsexed  Found in streams tributaries to the rivers Maquiné, Três Forquilhas and Mampituba, in the northeastern coastal plains of Rio Grande do Sul and southern Santa Catarina States (Ref. 98446). - 
Heptapteridae Rhamdia enfurnada Bichuette & Trajano, 2005 Fr native  Jundiá (Portuguese)   Known from the Gruna do Enfurnado, Serra do Ramalho in southwestern Bahia State, middle São Francisco River basin (Ref. 56934). - 
Heptapteridae Rhamdia foina (Müller & Troschel, 1849) Fr native   16.50 cm SL male/unsexed  Known from Branco, Negro, Tocantins and Trombetas River basins (Ref. 36914). + 
Heptapteridae Rhamdia itacaiunas Silfvergrip, 1996 Fr endemic   23.80 cm SL male/unsexed  Known from the middle Tocantins River basin (Ref. 36914). Type locality: Rio Tocantins drainage, `Igarapé Repartimento', Est. Amazonas, Brazil (Ref. 26282). - 
Heptapteridae Rhamdia jequitinhonha Silfvergrip, 1996 Fr endemic  Bagre (Portuguese), Jundiá (Portuguese)   16.10 cm SL male/unsexed  Known from Jequitinhonha River basin (Ref. 36914). Type locality: Rio Araçuaí, Santa Rita, Est. Minas Gerais, Brazil (Ref. 26282). + 
Heptapteridae Rhamdia laukidi Bleeker, 1858 Fr native  Jandiá (Portuguese)   33.00 cm SL male/unsexed    + 
Heptapteridae Rhamdia muelleri (Günther, 1864) Fr native    20.80 cm SL male/unsexed    + 
Heptapteridae Rhamdia poeyi Eigenmann & Eigenmann, 1888 Fr native   19.70 cm SL male/unsexed  Known from Tocantins River basin (Ref. 36914). Type locality: Goiás, Brazil (Ref. 26282). + 
Heptapteridae Rhamdia quelen (Quoy & Gaimard, 1824) Fr, Fi, Aq native  Jandia (Portuguese), Bagre (Portuguese), Bagre amarelo (Portuguese), Bagre da lagoa (Portuguese), Bagre de lagoa (Portuguese), Bagre guarié (Portuguese), Bagre morcego (Portuguese), Bagre sapo (Portuguese), Bagre sapo das pedras (Portuguese), Jandiá (Portuguese), Jandiaí (Portuguese), Jundiá (Portuguese), Jundiá amarelo (Portuguese), Jundiá tinga (Portuguese), Mandi (Portuguese), Mandí bagre (Portuguese), Mandi chorão (Portuguese), Mandí chorão (Portuguese), Mandi guaru (Portuguese), Nhandiá (Portuguese), Sapipoca (Portuguese) scarce (very unlikely) 61.00 cm TL male/unsexed  Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076), Rio Sao Francisco (Ref. 6868), Piracicaba (Ref. 50076), Uruguay (Ref. 79585) Machado (Ref. 97589), Acre (Ref. 97592) and Betari River basins (Ref. 38979). Also Ref. 53011. + 
Heptapteridae Rhamdia schomburgkii Bleeker, 1858 Fr native  Jandiá (Portuguese), Jundiá (Portuguese)   Known from th Rio Negro, Amazonas. - 
Heptapteridae Rhamdioglanis frenatus Ihering, 1907 Fr endemic  Mandi (Portuguese)  22.00 cm TL male/unsexed  Type locality, riverlets of the Island of S. Sebastião, State of S. Paulo (Ref. 36914). - 
Heptapteridae Rhamdioglanis transfasciatus Miranda Ribeiro, 1908 Fr endemic  Bagre (Portuguese), Jundiá (Portuguese), Mandi-pintado (Portuguese)   19.00 cm SL male/unsexed  Known from coastal streams in Rio de Janeiro to Santa Catarina (Ref. 36914). Type locality, Rio Bethary (Ref. 36914). + 
Heptapteridae Rhamdiopsis krugi Bockmann & Castro, 2010 Fr native  Bagre cego (Portuguese), Bagrinho (Portuguese)  3.71 cm SL male/unsexed  Found in the lake inside the Poço Encantado cave, and isolated pools inside the Lapa do Bode and Natal caves, which belong to the speleological province of Bambuí, northeastern Brazil, State of Bahia, in the Chapada Diamantina region (Ref. 86271). - 
Heptapteridae Rhamdiopsis microcephala (Lütken, 1874) Fr endemic  Bagre (Portuguese), Bagrinho (Portuguese), Jundiá (Portuguese)   7.80 cm SL male/unsexed  Known from the upper Paraná and São Francisco River basins (Ref. 36914). Type locality: Rio das Velhas, Brazil (Ref. 26282, 6868). - 
Heptapteridae Rhamdiopsis moreirai Haseman, 1911 Fr endemic  Bagre (Portuguese), Jundiá (Portuguese), Mandizinho (Portuguese)  11.70 cm SL male/unsexed  Known from the Iguaçu and Ribeira de Iguape River basins (Ref. 36914). Found in the Rio Iquaçu, Serrinha Parana (Ref. 6868). + 
Rhamphichthyidae Rhamphichthys atlanticus Triques, 1999 Fr native   67.30 cm SL male/unsexed  Type locality, Viana Lake, Pindaré-Mearim river system, MA (Ref. 35403). - 
Rhamphichthyidae Rhamphichthys drepanium Triques, 1999 Fr native   45.00 cm SL male/unsexed  Known from the confluence of Rios Negro and Solimões and the mouth of the Rio Japurá (Ref. 35403). - 
Rhamphichthyidae Rhamphichthys hahni (Meinken, 1937) Fr native  Tuvira (Portuguese), Tuvira-bicuda (Portuguese)   26.70 cm TL male/unsexed  Reported from the Uruguay River (Ref. 79585). Also recorded from Pantanal (Ref. 81048). + 
Rhamphichthyidae Rhamphichthys heleios Carvalho & Albert, 2015 Fr native   40.00 cm SL male/unsexed  Known from the Solimões and Amazon rivers upstream of the mouth of the Madeira River; also from a single locality in the Guaporé River (Ref. 99943). - 
Rhamphichthyidae Rhamphichthys lineatus Castelnau, 1855 Fr native    54.00 cm TL male/unsexed   - 
Rhamphichthyidae Rhamphichthys longior Triques, 1999 Fr native   80.00 cm SL male/unsexed  Type locality, Paru Lake at Oriximiná, PA (Ref. 35403). - 
Rhamphichthyidae Rhamphichthys marmoratus Castelnau, 1855 Fr native  Ituí terçado (Portuguese), Lampreia (Portuguese), Lampreia bico fino (Portuguese), Tubí (Portuguese), Tuvira (Portuguese)   65.00 cm TL male/unsexed  Found in the Amazon and Araguaia River basins (Ref. 36685). - 
Rhamphichthyidae Rhamphichthys rostratus (Linnaeus, 1766) Fr native  Itui-terçado (Portuguese), Ituí terçado (Portuguese), Lampreia (Portuguese), Peixe espada (Portuguese), Peixe-tatu (Portuguese), Sarapó (Portuguese), Sarató (Portuguese)   100.00 cm TL male/unsexed  Present in the Oyapock River which forms the border between French Guiana and Brazil (Ref. 12225). + 
Cynodontidae Rhaphiodon vulpinus Spix & Agassiz, 1829 Fr, Fi, Sp native  Dentudo (Portuguese), Cachorra facão (Portuguese), Cachorra gata (Portuguese), Cachorrão (Portuguese), Chafalote (Portuguese), Cigarra (Portuguese), Dourada-cadela (Portuguese), Dourado cachorro (Portuguese), Dourado cadela (Portuguese), Iauarana (Portuguese), Jauarana (Portuguese), Peixe cigarra (Portuguese), Peixe-cachorro (Portuguese), Peixe-cadela (Portuguese), Piarapucu (Portuguese), Pirá andirá (Portuguese), Ripa (Portuguese), Saicanga (Portuguese), Saranha (Portuguese), Sardinha gata (Portuguese), Tambiu (Portuguese)   80.00 cm SL male/unsexed 21.7 SL Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076), and the Uruguay River (Ref. 79585). Also Ref. 12202, 38270. + 
Loricariidae Rhinelepis aspera Spix & Agassiz, 1829 Fr, Fi native  Cascudo-preto (Portuguese), Acari (Portuguese), Acarí (Portuguese), Cascudo leiteiro (Portuguese), Chinelão (Portuguese), Chinelo (Portuguese), Congoá (Portuguese), Coró (Portuguese), Coró roncador (Portuguese), Guacari açu (Portuguese), Leiteiro (Portuguese), Roncador (Portuguese), Sapatão (Portuguese)   49.00 cm TL male/unsexed 18.2 TL Regarded as threatened in the state of Minas Gerais (Ref. 26603). Known from Rio São Francisco (Ref. 33317) and Pircacicaba river (Ref. 50076). Also Ref. 36817, 43112. - 
Loricariidae Rhinelepis strigosa Valenciennes, 1840 Fr native  Cascudo-preto (Portuguese), Mulita-tatu (Portuguese)  48.00 cm SL male/unsexed  Collected from rio Ibicui-Mirim on mouth of rio Toropi, São Vicente do Sul, rio Grande do Sul (Ref. 43112). + 
Characidae Rhinobrycon negrensis Myers, 1944 Fr native   3.90 cm SL male/unsexed  Recorded from the Rio Negro. - 
Doradidae Rhinodoras boehlkei Glodek, Whitmire & Orcés V., 1976 Fr native    17.00 cm TL male/unsexed   + 
Doradidae Rhinodoras dorbignyi (Kner, 1855) Fr native  Botoado (Portuguese), Armado (Portuguese), Marieta (Portuguese)   50.00 cm TL male/unsexed  Known from the Rio da Prata (Ref. 6868). Found in the Paraná River (Ref. 37054). + 
Loricariidae Rhinolekos britskii Martins, Langeani & Costa, 2011 Fr native   4.00 cm SL male/unsexed  Found in streams from rio Paranaíba drainage, upper rio Paraná system in Goiás State (Ref. 86681). - 
Loricariidae Rhinolekos capetinga Roxo, Ochoa, Silva & Oliveira, 2015 Fr native   3.91 cm SL male/unsexed  Found in two localities at the córrego da Branca and one locality at the córrego Roncador, all drainages of the rio Tocantizinho, rio Tocantins basin. This is the first species of this genus in the Amazon basin (Ref. 99822). - 
Loricariidae Rhinolekos garavelloi Martins & Langeani, 2011 Fr native   3.62 cm SL male/unsexed  Known from the type locality, stream tributary to rio Paranaíba drainage, upper rio Paraná system in Caldas Novas, Goiás State (Ref. 86681). - 
Loricariidae Rhinolekos schaeferi Martins & Langeani, 2011 Fr native   3.84 cm SL male/unsexed  Known from the type locality, a stream tributary to rio Paranaíba drainage, upper rio Paraná system in Alexânia, Goiás State (Ref. 86681). - 
Characidae Rhinopetitia myersi Géry, 1964 Fr native   3.04 cm SL male/unsexed  Recorded from the Rio Araguaia. - 
Characidae Rhinopetitia potamorhachia Netto-Ferreira, Birindelli, Sousa & Menezes, 2014 Fr native   4.41 cm SL male/unsexed ;4.45 cm SL female  Known from Rio Teles Pires, a tributary of the Rio Tapajós, downstream of the Sete Quedas rapids in Jacareacanga, Pará. Found along sandy beaches of the Rio Teles Pires in an area significantly affected by the construction of the Teles Pires hydroelectric dam. This hydropower project will pose adverse effect on the local fish fauna including the only known populations of this species (Ref. 111429). - 
Dorosomatidae Rhinosardinia amazonica (Steindachner, 1879) Fr, Br native  Sadinha da água doce (Portuguese), Sardinha de serra (Portuguese), Sardinha-d'água-doce (Portuguese)  11.00 cm TL male/unsexed  Also Ref. 5217. + 
Dorosomatidae Rhinosardinia bahiensis (Steindachner, 1879) Fr, Br native  Sardinha (Portuguese)  8.00 cm SL male/unsexed   + 
Loricariidae Rhinotocinclus loxochelis Reis & Lehmann, 2022 Fr native   2.31 cm SL male/unsexed  Type locality of Rhinocinclus loxochelis from a creek in Jamanxim National Forest, Itaituba, Pará, Brazil, MPEG 38957. Known from creeks tributary to the rio Jamanxim, rio Tapajós basin, in the Jamanxim National Forest, Pará, Brazil (Ref. 128924). - 
Loricariidae Rhinotocinclus marginalis Reis & Lehmann, 2022 Fr native   2.51 cm SL male/unsexed  Type locality of Rhinocinclus marginalis from rio Iriri at Cachoeira Grande, ca. 15 km upstream from confluence with rio Xingu, Piranhaquara, Pará, MCP 54748. known from tributaries to the lower rio Xingu and rio Iriri, in the state of Pará, Brazil (Ref. 128924). - 
Loricariidae Rhinotocinclus pilosus Reis & Lehmann, 2022 Fr native   2.26 cm SL female  Type locality of Rhinotocinclus pilosus from igarapé Traíra, ca. 35 km E of rio Madeira on Transamazon road, Humaitá, Amazonas, Brazil, UFRO-ICT 27700. Known from creeks tributary to the rio Madeira east of Humaitá, Amazonas (Ref. 128924). - 
Pseudopimelodidae Rhyacoglanis paranensis Shibatta & Vari, 2017 Fr native   8.92 cm SL male/unsexed  Type locality of Rhyacoglanis paranensis: upper Rio Parana basin (Ref. 128485) + 
Pseudopimelodidae Rhyacoglanis seminiger Shibatta & Vari, 2017 Fr native   7.78 cm SL male/unsexed  Type locality of Rhyacoglanis seminiger: Mato Grosso, Tapajós basin: rio Juruena, Pequena Central Hidrelétrica Cidezal. Collected in rapids of the rio Juruena and the rio Arinos, in the foothills of the Serra do Parecis (Ref. 128485). - 
Doradidae Rhynchodoras woodsi Glodek, 1976 Fr misidentification    10.50 cm SL male/unsexed  Found in the upper Rio Xingu (Ref. 6868). Probably a misidentification (occurrence in this country not confirmed by M. Sabaj and C.J. Ferraris Jr.). + 
Doradidae Rhynchodoras xingui Klausewitz & Rössel, 1961 Fr native   6.30 cm SL male/unsexed  Found in the upper Rio Xingu (Ref. 6868). + 
Anostomidae Rhytiodus argenteofuscus Kner, 1858 Fr, Fi native  Araçu (Portuguese), Aracu (Portuguese), Pau de nêgo (Portuguese), Pau de nêgro (Portuguese), Pau de vaqueiro (Portuguese)   32.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 598, 36801). Type locality: Rio Negro, Brazil. + 
Anostomidae Rhytiodus elongatus (Steindachner, 1908) Fr native    Recorded from Rio Purus (Ref. 598, 36801). - 
Anostomidae Rhytiodus microlepis Kner, 1858 Fr native    33.20 cm SL male/unsexed  Known from the Amazon River (Ref. 36801). + 
Loricariidae Rineloricaria aequalicuspis Reis & Cardoso, 2001 Fr native    16.08 cm SL male/unsexed  Types collected from Terra de Aréia, rio Três Forquilhas, Rio Grande do Sul; also from rio Maquiné. Also occurs in rio Mampituba and rio Araranguá drainages in NE Rio Grande do Sul and southern Santa Catarina. Inhabits creeks to large rivers with shallow to deep water, dwelling among bottom rocks and stones (Ref. 40941). Also Ref. 36389. + 
Loricariidae Rineloricaria anhaguapitan Ghazzi, 2008 Fr native   12.65 cm SL male/unsexed  Known from the tributaries of the Rio Passo Fundo of the upper Rio Uruguay in Rio Grande do Sul (Ref. 75800). + 
Loricariidae Rineloricaria anitae Ghazzi, 2008 Fr native   11.74 cm SL male/unsexed  Known from Rio Canoas in Santa Catarina (Ref. 75800). + 
Loricariidae Rineloricaria baliola Rodriguez & Reis, 2008 Fr native   23.90 cm SL male/unsexed  Found in the drainages of Rio Jacuí, Rio Taquari and lower portions of tributaries to the Laguna dos Patos (Ref. 75788). + 
Loricariidae Rineloricaria cacerensis (Miranda Ribeiro, 1912) Fr native    Known from Mato Grosso, rio Paraguai at Cáceres, and lagoa de Cáceres, Corumbá (Ref. 40941). Also Ref. 6868, 36389. - 
Loricariidae Rineloricaria cadeae (Hensel, 1868) Fr native  Cascudo viola (Portuguese), Viola (Portuguese), Violinha (Portuguese)   12.82 cm SL male/unsexed  Occurs throughout most of the Laguna dos Patos drainage (Ref. 75788). Known from Rio Grande do Sul; rio Vacacaí on highway BR 290, São Gabriel; arroio Mata Olho on road from Pedro Osório to Basílio, Pedro Osório (Ref. 40941). Also Ref. 36389. + 
Loricariidae Rineloricaria capitonia Ghazzi, 2008 Fr native   19.17 cm SL male/unsexed  Known from Rio Alegre and Rio Palmeira (tributary of the Rio Ijuí) and Rio Passo Fundo in Rio Grande do Sul (Ref. 75800). + 
Loricariidae Rineloricaria castroi Isbrücker & Nijssen, 1984 Fr native    16.00 cm SL male/unsexed  Known from the Trombetas (Ref. 36389), Purus and Acre River basin (Ref. 97592). - 
Loricariidae Rineloricaria cubataonis (Steindachner, 1907) Fr native  Cascudo (Portuguese)  5.40 cm SL male/unsexed   - 
Loricariidae Rineloricaria daraha Rapp Py-Daniel & Fichberg, 2008 Fr native   20.09 cm SL male/unsexed   - 
Loricariidae Rineloricaria fallax (Steindachner, 1915) Fr native   15.70 cm SL male/unsexed  Known from the Branco River drainage, Amazon River drainage (Ref. 36389). + 
Loricariidae Rineloricaria formosa Isbrücker & Nijssen, 1979 Fr native  Uacari (Portuguese), Uiaticona (Portuguese)   15.20 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36389). Found in Roraima, rio Uraricoera, Maracá (Ref. 40941). + 
Loricariidae Rineloricaria hasemani Isbrücker & Nijssen, 1979 Fr native   19.80 cm SL male/unsexed  Known from the lower Amazon or Tocantins River basin (Ref. 36389). + 
Loricariidae Rineloricaria henselii (Steindachner, 1907) Fr native   7.50 cm SL male/unsexed  Found in the Cubatão River in southern Santa Catarina (Ref. 36389). - 
Loricariidae Rineloricaria heteroptera Isbrücker & Nijssen, 1976 Fr native   13.30 cm SL male/unsexed  Known from rio Amazonas at Ducke Reserve, near Manaus (Ref. 40941). Recorded from Machado river basin (Ref. 97589). Also Ref. 6868, 36389. - 
Loricariidae Rineloricaria hoehnei (Miranda Ribeiro, 1912) Fr native   5.80 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 36389). - 
Loricariidae Rineloricaria isaaci Rodriguez & Miquelarena, 2008 Fr native   10.20 cm SL male/unsexed   - 
Loricariidae Rineloricaria jaraguensis (Steindachner, 1909) Fr native   18.50 cm male/unsexed  Known from Rio Jaraguà, Brazil (Ref. 6868). + 
Loricariidae Rineloricaria konopickyi (Steindachner, 1879) Fr native   9.60 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36389). - 
Loricariidae Rineloricaria kronei (Miranda Ribeiro, 1911) Fr native  Cascudo (Portuguese)   Known from São Paulo; rio Iporanga at Casa de Pedra, Iporanga; waterfall of rio Palmital, about 1 km from mouth of rio Ribeira do Iguape, Iguape (Ref. 40941). Also Ref. 6868. - 
Loricariidae Rineloricaria lanceolata (Günther, 1868) Fr native  Cascudo (Portuguese), Viola (Portuguese)   12.30 cm TL male/unsexed  Known from a creek on the road from Cuiabá to Porto Velho, about 7 km N of Pontes e Lacerda, Mato Grosso and Tocantins, rio Água fria at Fazenda Praia Alta 2, on road from Araguaçu (Ref. 40941). Found in the Acre and Purus River basins (Ref. 97592). + 
Loricariidae Rineloricaria langei Ingenito, Ghazzi, Duboc & Abilhoa, 2008 Fr native   11.65 cm SL male/unsexed  Found in the rio Iraí, a headwater river of upper rio Iguaçu drainage, in Curitiba, Paraná State (Ref. 79021). - 
Loricariidae Rineloricaria latirostris (Boulenger, 1900) Fr native  Cascudo (Portuguese), Cascudo viola (Portuguese)   36.00 cm TL male/unsexed  Found in the Paraná River basin (Ref. 36389). Known from Piracicaba, São Paulo ribeirão do Segredo, tributary of rio São Marcos, Catalão, Goiás (Ref. 40941). Also Ref. 6868, 36389. + 
Loricariidae Rineloricaria lima (Kner, 1853) Fr native  Acarí lima (Portuguese), Acary lima (Portuguese), Aperta galha (Portuguese), Barbado (Portuguese), Cascudo (Portuguese), Cascudo barbado (Portuguese), Cascudo barbudo (Portuguese), Cascudo chinelo (Portuguese), Cascudo espada (Portuguese), Cascudo lima (Portuguese), Viola (Portuguese)      - 
Loricariidae Rineloricaria longicauda Reis, 1983 Fr native   13.17 cm SL male/unsexed  Known from Rio Grande do Sul, arroio Xasquiero, on highway BR-116 between Pelotas and Arroio Grande and rio Jaguarão near mouth of rio Telho, Jaguarão (Ref. 40941). Found in lowland tributaries to the Lagoa Mirim and northern Laguna dos Patos, and on small isolated lagoons of the coastal plains south of Tramandai (Ref. 75788). Also Ref. 6868, 36389. + 
Loricariidae Rineloricaria maacki Ingenito, Ghazzi, Duboc & Abilhoa, 2008 Fr native    13.62 cm SL male/unsexed  Found in the middle and lower rio Iguaçu, a tributary of the rio Paraná basin (Ref. 79021). - 
Loricariidae Rineloricaria malabarbai Rodriguez & Reis, 2008 Fr native   10.20 cm SL male/unsexed  Known from the drainages of Rio Jacuí and Rio Camaquã (Ref. 75788). + 
Loricariidae Rineloricaria maquinensis Reis & Cardoso, 2001 Fr native    8.50 cm SL male/unsexed  Type locality, tributary to rio Maquiné, arroio Água arada, Rio Grande do Sul. Also known from the rio Araranguá basin, Santa Catarina but not collected so far in the intermediate drainages of the rio Três Forquilhas and rio Mampituba. Inhabits small creeks and rivers with shallow, clear water, lurking among the bottom rocks and stones (Ref. 40941). Also Ref. 36389. - 
Loricariidae Rineloricaria melini (Schindler, 1959) Fr native   13.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36389). + 
Loricariidae Rineloricaria microlepidogaster (Regan, 1904) Fr, Or native   19.29 cm SL male/unsexed  Known from Rio Grande do Sul, arroio Camaquã Chico, on road from Bagé to Lavras do Sul, Bagé (Ref. 40941). Occurs throughout most of the Laguna dos Patos drainage; also found in the Rio Taquari (Ref. 75788). Also Ref. 6868, 36389. + 
Loricariidae Rineloricaria microlepidota (Steindachner, 1907) Fr native   14.50 cm male/unsexed  Found in the Juruá River basin (Ref. 36389). - 
Loricariidae Rineloricaria nigricauda (Regan, 1904) Fr native    6.50 cm SL male/unsexed  Known from Rio de Janeiro, rio Calçado, tributary to rio paraíba do Sul near road BR-393, Três Rios and ribeirão Santa Rita, at highway BR-116, Teresópolis (Ref. 40941). Also Ref. 6868. 36389. - 
Loricariidae Rineloricaria osvaldoi Fichberg & Chamon, 2008 Fr native   16.83 cm SL male/unsexed   - 
Loricariidae Rineloricaria parva (Boulenger, 1895) Fr native  Cascudo espada (Portuguese), Cascudo viola (Portuguese)   11.00 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 36389). Found in the Rio Grande do Sul, rio Ibicuí drainage (Ref. 40941). Also Ref. 6868. + 
Loricariidae Rineloricaria pentamaculata Langeani & de Araujo, 1994 Fr native    Known from São Paulo, rio Turvo, Ourinhos and ribeirão Grande at Pardinho (Ref. 40941). Also Ref. 36389. - 
Loricariidae Rineloricaria phoxocephala (Eigenmann & Eigenmann, 1889) Fr native   15.00 cm SL male/unsexed  Found in the Amazon River basin (Ref. 36389). Known from the Amazonas, rio Acre at Boca do Acre (Ref. 40941). Also Ref. 6868, 36389. - 
Loricariidae Rineloricaria platyura (Müller & Troschel, 1849) Fr native   14.00 cm SL male/unsexed   - 
Loricariidae Rineloricaria quadrensis Reis, 1983 Fr native   14.70 cm SL male/unsexed  Known from Rio Grande do Sul, lago dos Quadros, Osório; rio Maquiné, Maquiné; channel between lago Emboaba and lagoa Emboabinha, Osório; lago dos Quadros at nautical park, Capão da Canoa (Ref. 40941). Also Ref. 6868, 36389. - 
Loricariidae Rineloricaria reisi Ghazzi, 2008 Fr native   19.77 cm SL male/unsexed  Known from the Rio Piratini and Rio Conceição of the Rio Uruguay basin in Rio Grande do Sul (Ref. 75800). + 
Loricariidae Rineloricaria sanga Ghazzi, 2008 Fr native   9.95 cm SL male/unsexed  Known only from the vicinity of Iraí in Rio Uruguay basin (Ref. 75800). + 
Loricariidae Rineloricaria setepovos Ghazzi, 2008 Fr native   10.60 cm SL male/unsexed  Known from the Rio Piratini of the Rio Uruguay basin in Santo Ângelo, Rio Grande do Sul (Ref. 75800). + 
Loricariidae Rineloricaria steindachneri (Regan, 1904) Fr native  Cascudo (Portuguese)   19.00 cm TL male/unsexed  Known from Espíriro Santo, rio São José dos Torres on highway BR-101, between São José dos Torres and Travessão (Ref. 40941). Also Ref. 6868, 36389. - 
Loricariidae Rineloricaria stellata Ghazzi, 2008 Fr native    10.95 cm SL male/unsexed  Known from rio Buricá, rio Ijuí, rio Piratini and rio Ibicuí of the Rio Uruguay basin (Ref. 75800). + 
Loricariidae Rineloricaria strigilata (Hensel, 1868) Fr native  Cascudo viola (Portuguese), Viola (Portuguese), Violinha (Portuguese)  13.86 cm SL male/unsexed  Found throughout most of the Laguna dos Patos drainage (Ref. 75788). Known from Rio Grande do Sul, arroio Basílio at Basílio, Erval; arroio Araçá on highway BR-116, Sertão Santana; rio Guaíba near mouth of arroio Celupa, Guaíba (Ref. 40941). Also Ref. 6868, 36389, 58359. + 
Loricariidae Rineloricaria teffeana (Steindachner, 1879) Fr native   14.00 cm SL male/unsexed  Found in the Amazon River basin (Ref. 36389). + 
Loricariidae Rineloricaria tropeira Ghazzi, 2008 Fr native   10.28 cm SL male/unsexed  Known from the tributaries of the rio Pelotas and rio Canoas of the upper rio Uruguay basin (Ref. 75800). + 
Loricariidae Rineloricaria zaina Ghazzi, 2008 Fr native    13.86 cm SL male/unsexed  Widespread from the confluence of the rio Canoas with the rio Pelotas to the rio Ibicuí, rio Uruguay basin (Ref. 75800). + 
Rivulidae Rivulus carolinae Vermeulen & Mejia-Vargas, 2020 Fr questionable   2.76 cm SL male/unsexed ;2.50 cm SL female  Although the creek was on the Colombian side of the border, this species may also live in Brazil (Ref. 130065). - 
Rivulidae Rivulus flammaecauda Vermeulen & Mejia-Vargas, 2020 Fr questionable   3.55 cm SL male/unsexed  Although the creek was on the Colombian side of the border, this species may also live in Brazil (Ref. 130065). - 
Rivulidae Rivulus formosensis Costa, 2008 Fr native   3.31 cm SL male/unsexed ;3.46 cm SL female  Found only in the Formoso river floodplains, upper Corrente river drainage of the upper Paraná river basin in central Brazil, in altitudes between 745 and 800 m (Ref. 75995). - 
Characidae Roeboexodon geryi Myers, 1960 Fr native   15.00 cm SL male/unsexed  Known from Amazon, Tocantins, Xingu and Tapajos River basins (Ref. 38376). + 
Characidae Roeboexodon guyanensis (Puyo, 1948) Fr native   12.00 cm SL male/unsexed  Occurs in the Tocantins and the Xingu rivers (Ref. 12225). + 
Characidae Roeboides affinis (Günther, 1868) Fr native  Cacunda (Portuguese), Madalena (Portuguese)   11.00 cm SL male/unsexed    + 
Characidae Roeboides biserialis (Garman, 1890) Fr native    4.80 cm SL male/unsexed  Known from the middle Amazon River basin (Ref. 36811). + 
Characidae Roeboides descalvadensis Fowler, 1932 Fr native  Dentudo (Portuguese), Saicanga (Portuguese)   8.90 cm SL male/unsexed 39 TL Known from the Rio Paraguai, Cáceres and vicinity in Mato Grosso (Ref. 26633). + 
Characidae Roeboides dispar Lucena, 2001 Fr native  Madalena (Portuguese)  8.11 cm SL male/unsexed  Type locality, Fos do [rio] Arara, bacia do rio Juruá, Reserva Extrativista Alto Juruá, Acre (Ref. 46206). - 
Characidae Roeboides margareteae Lucena, 2003 Fr native   18.47 cm SL male/unsexed  Found only in Parnaíba and Pindaré-Mearim river drainages in northeastern Brazil (Ref. 57858). + 
Characidae Roeboides microlepis (Reinhardt, 1851) Fr native  Cacunda (Portuguese), Corcunda (Portuguese), Saicanga (Portuguese)   20.00 cm SL male/unsexed  Known from rio Paraguai (Ref. 57858). - 
Characidae Roeboides myersii Gill, 1870 Fr, Fi native  Madalena (Portuguese), Crica (Portuguese), Zé do ó (Portuguese)   22.00 cm TL male/unsexed  Found in fish markets in Santarém (Ref. 12202). Also Ref. 36811. + 
Characidae Roeboides oligistos Lucena, 2000 Fr native   7.00 cm SL male/unsexed  Found in Amazon, Negro, Branco, Tapajós, and Trombetas River basins (Ref. 36811). - 
Characidae Roeboides prognathus (Boulenger, 1895) Fr native  Saicanga (Portuguese), Mato Grosso scale-eating characin (English), Prognathous scale-eating characin (English), Prognatic scale-eating characin (English), Cacunda (Portuguese), Cacundinha (Portuguese), Corcunda (Portuguese), Corcundinha (Portuguese)   18.50 cm SL male/unsexed  Known from the Mato Grosso (Ref. 598). + 
Characidae Roeboides sazimai Lucena, 2007 Fr native   8.36 cm SL male/unsexed  Known from Parnaíba and Pindaré-Mearim drainages in northeastern Brazil (Ref. 75795). + 
Characidae Roeboides xenodon (Reinhardt, 1851) Fr native  Cachorra (Portuguese), Piaba (Portuguese), Piaba-facão (Portuguese)   8.20 cm SL male/unsexed  Known from São Francisco River basin (Ref. 598, 36811). + 
Acestrorhynchidae Roestes itupiranga Menezes & Lucena, 1998 Fr native   14.20 cm SL male/unsexed  Known from the Rio Tocantins basin. Also Ref. 38270. - 
Acestrorhynchidae Roestes molossus (Kner, 1858) Fr native    21.60 cm SL male/unsexed  So far known only from the Rio Madeira basin and upper trributaries flowing into it (Ref. 33012). Known from Rio Guapore, Jurua and Livramento rivers (Ref. 598). Also Ref. 38270. - 
Acestrorhynchidae Roestes ogilviei (Fowler, 1914) Fr native    18.70 cm SL male/unsexed  Known from Amazonas in Rio Jurua and Rio Marauia, and from Roraima in Rio Branco and Rio Mucajai. Also Ref. 38270. - 
Cichlidae Rondonacara hoehnei (Miranda Ribeiro, 1918) Fr, Thr endemic    7.22 cm SL male/unsexed  Known only from the Amazon River basin, in the Araguaia River drainage (Ref. 36377). Found in the upper das Mortes River basin, Araguaia River drainage, central Brazil (Ref. 101427). Considering the restricted distribution and the widespread and accelerated destruction of natural habitats, the conservation status of Rondonacara hoehnei has to be stated to be a 'critically endangered' (Ref. 101427). Also Ref. 12251. + 
Bryconidae Salminus brasiliensis (Cuvier, 1816) Fr, Fi, Aq native  Dourado (Portuguese), Pirajuba (Portuguese), Saipe (Portuguese), Salmo dourado (Portuguese) scarce (very unlikely) 100.00 cm SL male/unsexed 37 SL Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river. Found in the Piracicaba river (Ref. 50076) and the Uruguay River (Ref. 79585). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 31923, 38376. + 
Bryconidae Salminus franciscanus Lima & Britski, 2007 Fr endemic  Dourado (Portuguese)   75.50 cm SL male/unsexed  Type locality, stream tributary to rio das Velhas, at Igreja Quebrada, near Jaguara, Pedro Leopoldo, Minas Gerais, MZUSP 89625 (holotype of Salminus franciscanus, 32.4 cm SL). Endemic from the rio São Francisco basin (Ref. 75797). + 
Bryconidae Salminus hilarii Valenciennes, 1850 Fr native  Tuburana (Portuguese), Dourado (Portuguese), Dourado branco (Portuguese), Gitubarana (Portuguese), Jatubarana (Portuguese), Jitubarana (Portuguese), Jutubarana (Portuguese), Matrinchã (Portuguese), Pirá iú (Portuguese), Rabo vermelho (Portuguese), Sardinha rabo de ouro (Portuguese), Sardinha rabo vermelho (Portuguese), Tabarana (Portuguese), Tubarana (Portuguese), Umbarana (Portuguese) scarce (very unlikely) 50.00 cm SL male/unsexed  Type locality, Rio Jaguaribe, Orós, Ceará (Ref. 30296). Also Ref. 38376. + 
Salmonidae Salmo salar Linnaeus, 1758 Fr not established   150 cm TL male/unsexed ;120 cm TL female   + 
Trichomycteridae Sarcoglanis simplex Myers & Weitzman, 1966 Fr native   2.10 cm NG male/unsexed  Known from the upper Negro River basin (Ref. 39970). Type locality: Tide pools below Sao Gabriel rapids of the Rio Negro (below the town of Uaupes) (Ref. 26282, 6868). + 
Anostomidae Sartor elongatus Santos & Jégu, 1987 Fr native   7.60 cm SL male/unsexed  Known from Trombetas and Mapuera River basins (Ref. 36801). Museum: Rio Trombetas, Cachoeira Porteira, foz do rio Mapuera, Pará, MZUSP 38578 (Ref. 27925). - 
Anostomidae Sartor respectus Myers & Carvalho, 1959 Fr native    Recorded from the upper Xingu River basin (Ref. 36801). + 
Anostomidae Sartor tucuruiensis Santos & Jégu, 1987 Fr native    11.00 cm SL male/unsexed  Known from the Tocantins River basin (Ref. 36801). Museum: Rio Tocantins, Tucuruí, Pará, MZUSP 38579 (paratypes, 2:10.65 - 10.98 cm SL) (Ref. 27925). - 
Cichlidae Satanoperca acuticeps (Heckel, 1840) Fr, Fi, Or native  Acará bicudo (Portuguese), Acará papa terra (Portuguese), Jurupari (Portuguese), Parupé (Portuguese) common (usually seen) 17.00 cm SL male/unsexed  Known from the Amazon River basin, in the Branco, lower Negro, and along the Solimões-Amazon rivers between the Tocantins and the lower Trombetas rivers (Ref. 36377). Found in fish markets in Santarém (Ref. 12202). Also Ref. 12251. + 
Cichlidae Satanoperca daemon (Heckel, 1840) Fr native  Acarra (Portuguese), Jurupari (Portuguese)   17.00 cm SL male/unsexed  Known from the Amazon River basin in the upper Negro River (Ref. 36377). Also Ref. 4537. + 
Cichlidae Satanoperca jurupari (Heckel, 1840) Fr, Fi native  Cara bicudo (Portuguese), Acará bicudo (Portuguese), Acará papa terra (Portuguese), Acará-chibante (Portuguese), Cará (Portuguese), Cará de lago (Portuguese), Cará serrotão (Portuguese), Cará-bicudo (Portuguese), Jurupari pindá (Portuguese)   26.00 cm SL male/unsexed ;23.30 cm SL female  Known from the Amazon River basin and in the Amapá (Ref. 36377). Recorded from Machado river basin (Ref. 97589). + 
Cichlidae Satanoperca lilith Kullander & Ferreira, 1988 Fr endemic    25.50 cm SL male/unsexed  Known from the Amazon River basin, along the Solimões-Amazon River from the Japurá River to the Trombetas River, also in the Negro River from the Curucuriari River to the mouth, and in the Branco River basin (Ref. 36377). Type locality, Urumari, Rio Negro drainage, Amazonas State (Ref. 26282). + 
Cichlidae Satanoperca pappaterra (Heckel, 1840) Fr native  Cará (Portuguese), Acará (Portuguese), Carito (Portuguese), Papaterra (Portuguese)   27.00 cm TL male/unsexed ;27.50 cm TL female 7.5 TL Known from the Amazon River basin in Guaporé River and Paraná River basin in Paraguay River drainage (Ref. 36377). + 
Anostomidae Schizodon altoparanae Garavello & Britski, 1990 Fr, Fi native    32.20 cm TL male/unsexed ;37.40 cm TL female 14.9 TL Known from Paraná River basin (Ref. 36801). Recorded from Piracicaba river (Ref. 50076). Museum: Rio Paraná, em frente a Jupiá, Mato Grosso, MZUSP 41102 (holotype of S. altoparanae, 18.2 cm SL) (Ref. 27925). - 
Anostomidae Schizodon australis Garavello, 1994 Fr native   33.40 cm SL male/unsexed  Known from the Uruguay River basin (Ref. 36801). Museum: Rio Uruguai, Porto de Santo Izidro, Município Sao Nicolau, Rio Grande do Sul, MZUSP 47445 (Ref. 27925). - 
Anostomidae Schizodon borellii (Boulenger, 1900) Fr native  Piava (Portuguese), Chimburé (Portuguese)   36.00 cm TL male/unsexed ;40.00 cm TL female 14.6 TL Known from Paraguay River basin (Ref. 36801). + 
Anostomidae Schizodon dissimilis (Garman, 1890) Fr native  Piau galo (Portuguese), Piau lavrado (Portuguese)   25.80 cm SL male/unsexed  Known from Poti River basin in Piauí (Ref. 36801). - 
Anostomidae Schizodon fasciatus Spix & Agassiz, 1829 Fr, Fi native  Piau lavrado (Portuguese), Acurupintado (Portuguese), Aracu (Portuguese), Aracu comum (Portuguese), Aracu pinima (Portuguese), Aracu pintado (Portuguese), Boca de chinelo (Portuguese), Boga (Portuguese), Lisa de água doce (Portuguese), Pau de igarapé (Portuguese), Pau de vaqueiro (Portuguese), Piau de Igarapé (Portuguese), Piau de vara (Portuguese), Taguara (Portuguese), Voga (Portuguese)   40.00 cm TL male/unsexed  Reported from the Amazon basin and Rio Tocantin (Ref. 12225); recorded from Rio Jurúa (lakes)(MZUSP No. 50274, Ref. 42843). Also Ref. 36801. + 
Anostomidae Schizodon intermedius Garavello & Britski, 1990 Fr, Fi native  Piava (Portuguese)  28.70 cm SL male/unsexed  Known from the upper Paraná River basin (Ref. 36801). Recorded from Piracicaba river (Ref. 50076). Museum: Ribeirao tributary to Rio Itaqueri, tributary to Rio Piracicaba, Aguas de Sao Pedro, Sao Paolo, MZUSP 41123 (holotype of S. intermedius, 21 cm SL) (Ref. 27925). Also Ref. 31923. - 
Anostomidae Schizodon isognathus Kner, 1858 Fr native  Peixe-rei (Portuguese), Peixe rey (Portuguese)   35.00 cm SL male/unsexed  Known from Paraguay River basin (Ref. 36801). - 
Anostomidae Schizodon jacuiensis Bergmann, 1988 Fr native  Voga (Portuguese)  34.80 cm TL male/unsexed  Known from Laguna dos Patos drainage (Ref. 36801). Museum: Rio Guaíba, Morro do Sabiá, Porto Alegre, Rio Grande do Sul, MZUSP 38864, 38865 (paratypes) (Ref. 27925). - 
Anostomidae Schizodon knerii (Steindachner, 1875) Fr native  Campineiro (Portuguese), Chimboré (Portuguese), Piau branco (Portuguese), Piau canudo (Portuguese), Piau-de-cheiro (Portuguese), Piava (Portuguese)   23.50 cm SL male/unsexed  Known from São Francisco River basin (Ref. 36801). - 
Anostomidae Schizodon nasutus Kner, 1858 Fr, Fi native  Chimborê (Portuguese), Amboré (Portuguese), Chimboré (Portuguese), Chimburé (Portuguese), Porrudo (Portuguese), Taguara (Portuguese), Timboré (Portuguese), Voga (Portuguese), Ximborê (Portuguese) scarce (very unlikely) 43.50 cm TL male/unsexed  Known from Paraná, Paraguay and Uruguay River basins (Ref. 36801). Found in Piracicaba river (Ref. 50076). Also Ref. 31923, 79585. + 
Anostomidae Schizodon rostratus (Borodin, 1931) Fr native    Known from Parnaíba River basin (Ref. 36801). - 
Anostomidae Schizodon vittatus (Valenciennes, 1850) Fr, Fi native  Araçu comum (Portuguese), Aracu (Portuguese), Aracu comum (Portuguese), Aracu pororoca (Portuguese), Araçu pororoca (Portuguese), Piau vara (Portuguese)   35.00 cm SL male/unsexed  Known from the Amazon and Araguaia River basins (Ref. 36801). Also Ref. 598. + 
Loricariidae Schizolecis guentheri (Miranda Ribeiro, 1918) Fr native   4.00 cm SL male/unsexed ;3.10 cm SL female  Type locality: Ilha de Sao Sebastiao, Estado de Sao Paulo, Brazil (Ref. 26282). Also Ref. 6868. + 
Trichomycteridae Schultzichthys bondi (Myers, 1942) Fr native    3.65 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39970). - 
Ariidae Sciades couma (Valenciennes, 1840) Fr, Br native  Bagre (Portuguese), Bagre catinga (Portuguese)   97.00 cm TL male/unsexed  Known from Goiana Estuary, Pernambuco (Ref. 114746). + 
Ariidae Sciades herzbergii (Bloch, 1794) Fr, Br, Fi native  Bagre-juba (Portuguese), Bagre (Portuguese), Bagre branco (Portuguese), Bagre guribu (Portuguese), Gurijuba (Portuguese), Jahu amazonense (Portuguese), Jau (Portuguese) occasional (usually not seen) 94.20 cm TL male/unsexed ;62.50 cm TL female 60 TL   + 
Callichthyidae Scleromystax barbatus (Quoy & Gaimard, 1824) Fr native  Sarro (Portuguese), Maria da serra (Portuguese), Sarrinho (Portuguese)   9.80 cm SL male/unsexed  Known from Santos (Sao Paulo) to Rio de Janeiro (Ref. 26041). Also in Betari River basin, Southeastern Brazil (Ref. 38979). + 
Callichthyidae Scleromystax macropterus (Regan, 1913) Fr, Or native    8.70 cm SL male/unsexed  Exported to North America as an aquarium fish (Ref. 4537). + 
Callichthyidae Scleromystax prionotos (Nijssen & Isbrücker, 1980) Fr native    5.30 cm SL male/unsexed  Found in coastal rivers in southeastern Brazil from Espírito Santo to São Paulo (Ref. 37395). + 
Callichthyidae Scleromystax salmacis Britto & Reis, 2005 Fr native     - 
Trichomycteridae Scleronema guapa Ferrer & Malabarba, 2020 Fr native   4.23 cm SL male/unsexed  Type locality of Scleronema guapa, Rio Grande do Sul State, Rosário do Sul, sanga Santo Antônio, tributary of rio Ibicuí da Armada, rio Ibicuí basin, lower rio Uruguay (Ref. 122319). - 
Trichomycteridae Scleronema ibirapuita Ferrer & Malabarba, 2020 Fr native   4.25 cm SL male/unsexed  Type locality of Scleronema ibirapuita, Rio Grande do Sul State, Santana do Livramento, ‘Área de Proteção Ambiental Ibirapuitã’ Conservation Unit, rio Ibirapuitã Chico, tributary of rio Ibirapuitã, rio Ibicuí basin, lower rio Uruguay (Ref. 122319). - 
Trichomycteridae Scleronema macanuda Ferrer & Malabarba, 2020 Fr native   8.40 cm SL male/unsexed  Type locality of Scleronema macanuda, Rio Grande do Sul State, Sentinela do Sul, irrigation water channel draining to arroio Velhaco, laguna dos Patos system. In the lower rio Uruguay basin, the species occurs in the rio Negro and tributaries (Ref. 122319). - 
Trichomycteridae Scleronema mate Ferrer & Malabarba, 2020 Fr native   5.01 cm SL male/unsexed  Type locality of Scleronema mate, Rio Grande do Sul, Venâncio Aires, arroio Grande, tributary of arroio Castelhano, rio Taquari basin, laguna dos Patos system. Known from four tributaries of the rio Jacuí: rio Caí, rio Pardo, rio Taquari, and rio dos Sinos (Ref. 122319). - 
Trichomycteridae Scleronema milonga Ferrer & Malabarba, 2020 Fr native   3.92 cm SL male/unsexed  Type locality of Scleronema milonga, Rio Grande do Sul, Dezesseis de Novembro, arroio Lageado Araçá, rio Ijuí basin, lower rio Uruguay. Known from rio Ijuí rio and Santa Rosa basins, tributaries to the left bank of rio Uruguay, southern Brazil (Ref. 122319). - 
Trichomycteridae Scleronema minutum (Boulenger, 1891) Fr native   4.00 cm SL male/unsexed  Found in Rio Grande do Sul (Ref. 39970). Type locality: San Lorenzo, Rio Grande do Sul, Brazil (Ref. 26282, 6868). + 
Trichomycteridae Scleronema operculatum Eigenmann, 1917 Fr native   8.00 cm male/unsexed  Found in Rio Grande do Sul (Ref. 39970). Type locality: Cacequi, Brazil (Ref. 26282). - 
Trichomycteridae Scleronema teiniagua Ferrer & Malabarba, 2020 Fr native   4.52 cm SL male/unsexed  Known from Rio Grande do Sul State, rio Quaraí basin, lower rio Uruguay (Ref. 122319). - 
Loricariidae Scobinancistrus aureatus Burgess, 1994 Fr endemic  Acari-da-pedra (Portuguese)  29.00 cm TL male/unsexed  Known from the Xingu River basin (Ref. 36713). + 
Loricariidae Scobinancistrus pariolispos Isbrücker & Nijssen, 1989 Fr native  Acari-da-pedra (Portuguese)  27.00 cm TL male/unsexed  Known from Tocantins and Tapajós River basins (Ref. 36713). + 
Scoloplacidae Scoloplax baileyi Rocha, Lazzarotto & Py-Daniel, 2012 Fr native   1.54 cm SL male/unsexed  Type locality, Amazonas State, Barcelos, Rio Negro basin, Igarapé do Ingá, right bank tributary of Rio Arara, Rio Unini basin, INPA 35637 (holotype of Scoloplax baileyi, 1.4 cm SL). Found in streams of the Rio Unini, lower Rio Negro basin and a single specimen (MZUSP 34760) found in Anavilhanas, lower Rio Negro basin, suggests a more widespread distribution (Ref. 92919). - 
Scoloplacidae Scoloplax baskini Rocha, de Oliveira & Rapp Py-Daniel, 2008 Fr native    1.61 cm SL male/unsexed  Type locality, Amazonas, Novo Aripuanã, rio Aripuanã, igarapé Palhalzinho, INPA 28658 (holotype of Scoloplax baskini, 1.44 cm SL). This species occurs among leaf litter in small clearwater tributaries of the middle part of rio Aripuanã, which is a right-bank tributary of the middle rio Madeira (Ref. 79026). - 
Scoloplacidae Scoloplax dicra Bailey & Baskin, 1976 Fr native    1.38 cm SL male/unsexed    - 
Scoloplacidae Scoloplax distolothrix Schaefer, Weitzman & Britski, 1989 Fr native   1.79 cm SL male/unsexed  Known from Araguaia (Ref. 36693), Xingu and Tocantins River basins (Ref. 33205). Also Ref. 81048. - 
Scoloplacidae Scoloplax dolicholophia Schaefer, Weitzman & Britski, 1989 Fr native   1.20 cm SL male/unsexed  Known from the Negro River basin (Ref. 36693). - 
Scoloplacidae Scoloplax empousa Schaefer, Weitzman & Britski, 1989 Fr native  Pantanal dwarf catfish (English)  1.99 cm SL male/unsexed   + 
Doradidae Scorpiodoras calderonensis (Vaillant, 1880) Fr native   15.07 cm SL male/unsexed  Known from the upper Amazon basin, including the Rio Solimões and lower portions of its tributaries, such as the Juruá, Japurá, and Tefé rivers (Ref. 86601). - 
Doradidae Scorpiodoras heckelii (Kner, 1855) Fr native  Dukeru (Portuguese)  16.10 cm SL male/unsexed   + 
Doradidae Scorpiodoras liophysus Sousa & Birindelli, 2011 Fr native    15.70 cm SL male/unsexed  Known from the Rio Madeira basin (Ref. 86601). - 
Prochilodontidae Semaprochilodus brama (Valenciennes, 1850) Fr native  Jaraqui (Portuguese), Jaraquí (Portuguese)   54.00 cm TL male/unsexed  Known from Tocantins and Xingu River basins (Ref. 37057). Also reported from Araguaia River, Amazon basin (Ref. 27778). Also Ref. 598. + 
Prochilodontidae Semaprochilodus insignis (Jardine, 1841) Fr, Fi native  Jaraqui (Portuguese), Geraki (Portuguese), Jaraqui açu (Portuguese), Jaraqui escama grande (Portuguese), Jaraqui escama grossa (Portuguese), Jaraqui-da-escama-grossa (Portuguese), Jeraqui (Portuguese)   22.00 cm SL male/unsexed ;29.50 cm SL female  Known from the Amazon River (Ref. 37057). Type locality, Rio Branco, Amazon system (Ref. 598). Also Ref. 12202. + 
Prochilodontidae Semaprochilodus taeniurus (Valenciennes, 1821) Fr, Fi native  Jaraqui (Portuguese), Jaraqui escama fina (Portuguese), Jaraqui-da-escama-fina (Portuguese)   27.20 cm SL male/unsexed  Known from central portions of the Amazon basin and tributary rivers (Ref. 37057). Also Ref. 598. + 
Characidae Serrapinnus aster Malabarba & Jerep, 2014 Fr native   3.32 cm SL male/unsexed  Known from the upper portions of the rio Tocantins basin, mainly in the tributaries of the rio Paraná and rio Tocantins (Ref. 96959). - 
Characidae Serrapinnus calliurus (Boulenger, 1900) Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)   4.40 cm SL male/unsexed  Type locality: Corandasiñho, Brazil (Ref. 37055). - 
Characidae Serrapinnus heterodon (Eigenmann, 1915) Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese), Piquira (Portuguese)   8.29 cm SL male/unsexed    + 
Characidae Serrapinnus kriegi (Schindler, 1937) Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)   2.36 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 37055). Found in Pantanal (Ref. 81048). + 
Characidae Serrapinnus lucindai Jerep & Malabarba, 2014 Fr native   2.96 cm SL male/unsexed  Known from the rio Tocantins-Araguaia basin (Ref. 96959). - 
Characidae Serrapinnus microdon (Eigenmann, 1915) Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)  4.20 cm SL male/unsexed  Known from the Paraguay (Ref. 37055) and Machado River basin (Ref. 97589). - 
Characidae Serrapinnus micropterus (Eigenmann, 1907) Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)   2.63 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37055). Type locality: Santarém, Pará, Brazil (Ref. 26282). - 
Characidae Serrapinnus notomelas (Eigenmann, 1915) Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese), Piquira (Portuguese)   3.56 cm SL male/unsexed 2.1 TL Known from the upper Paraná River basin (Ref. 37055). Type locality: Lake 4 mi. from Miguel Calmone, Rio Tieté basin, Brazil (Ref. 26282). Also Ref. 598. + 
Characidae Serrapinnus piaba (Lütken, 1875) Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese), Piquira (Portuguese)   4.20 cm TL male/unsexed  Known from the São Francisco River basin (Ref. 37055). + 
Characidae Serrapinnus potiguar Jerep & Malabarba, 2014 Fr native   3.23 cm SL male/unsexed  Known from the rio Ceará-Mirim basin in Rio Grande do Norte State, northeastern Brazil (Ref. 96867). - 
Characidae Serrapinnus sterbai Zarske, 2012 Fr native   3.54 cm SL male/unsexed  Known from several tributaries and the main course of the Rio Tocantins drainage (Ref. 96959). - 
Characidae Serrapinnus tocantinensis Malabarba & Jerep, 2014 Fr native   3.98 cm SL male/unsexed  Known throughout the rio Tocantins-Araguaia basin, from the upper to the lower portions of the system (Ref. 96959). - 
Characidae Serrapinnus zanatae Jerep, Camelier & Malabarba, 2016 Fr native   3.94 cm SL male/unsexed  Type locality of Serrapinnus zanatae. Currently known to inhabit the upper and middle portions of the rio Jequitinhonha basin, Minas Gerais State, southeastern region of Brazil (Ref. 119705). - 
Serrasalmidae Serrasalmus altispinis Merckx, Jégu & Santos, 2000 Fr native  Piranha (Portuguese)  21.00 cm TL male/unsexed  Known from the Amazon River basin, Uatumã River (Ref. 39031). Also Ref. 85594. + 
Serrasalmidae Serrasalmus brandtii Lütken, 1875 Fr endemic  Pirambeba (Portuguese), Pirampeba (Portuguese), Piranha branca (Portuguese), Piranha cachorro (Portuguese), Piranha da lagoa (Portuguese)   21.20 cm SL male/unsexed  Knonw from São Francisco River basin (Ref. 39031). + 
Serrasalmidae Serrasalmus compressus Jégu, Leão & Santos, 1991 Fr native  Piranha (Portuguese)   19.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39031). Recorded from Rio Madeira (Ref. 26758). + 
Serrasalmidae Serrasalmus eigenmanni Norman, 1929 Fr native  Piranha (Portuguese), Pirambeba (Portuguese), Piranha branca (Portuguese)   35.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39031). + 
Serrasalmidae Serrasalmus elongatus Kner, 1858 Fr, Fi native  Piranha comprida (Portuguese), Piranha (Portuguese), Piranha mucura (Portuguese)   30.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39031). + 
Serrasalmidae Serrasalmus geryi Jégu & Santos, 1988 Fr native   18.10 cm SL male/unsexed  Known from the Tocantins River basin (Ref. 39031). Recorded from Rio Araguaia, Araguacema, Goiás and Rio Tocantins, Pará (Ref. 26758). + 
Serrasalmidae Serrasalmus gibbus Castelnau, 1855 Fr native  Piranha (Portuguese)   25.50 cm SL male/unsexed  Known from Tocantins River basin (Ref. 39031). + 
Serrasalmidae Serrasalmus gouldingi Fink & Machado-Allison, 1992 Fr native  Piranha (Portuguese), Fula preto (Portuguese), Piranha fula (Portuguese)  27.94 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39031). Recorded from the Rio Negro and Rio Japura at Lago Amaña. + 
Serrasalmidae Serrasalmus hastatus Fink & Machado-Allison, 2001 Fr native  Piranha (Portuguese)  15.45 cm SL male/unsexed  Known from the Negro River basin (Ref. 39031). Also Ref. 85594. + 
Serrasalmidae Serrasalmus hollandi Eigenmann, 1915 Fr native    18.50 cm SL male/unsexed   + 
Serrasalmidae Serrasalmus humeralis Valenciennes, 1850 Fr native  Piranha (Portuguese), Pirambeta (Portuguese)  20.00 cm SL male/unsexed  Occurs in the Amazon basin (Ref. 39031). Recorded from the Oyapock River (Ref. 12225). Also Ref. 1739. + 
Serrasalmidae Serrasalmus maculatus Kner, 1858 Fr native  Catirina (Portuguese), Pirambeba (Portuguese), Piranha (Portuguese), Piranha amarela (Portuguese), Piranha mafura (Portuguese)   26.40 cm TL male/unsexed ;34.50 cm TL female 9.8 TL Known from the Uruguay River (Ref. 79585). Also Ref. 9080. + 
Serrasalmidae Serrasalmus manueli (Fernández-Yépez & Ramírez, 1967) Fr native  Piranha (Portuguese), Piranha murutinga (Portuguese), Piranha xidowa (Portuguese)  36.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39031). + 
Serrasalmidae Serrasalmus marginatus Valenciennes, 1837 Fr native  Catirina (Portuguese), Pirambeba (Portuguese), Piranha (Portuguese), Piranha branca (Portuguese)   27.10 cm TL male/unsexed ;32.40 cm TL female 11.5 TL   + 
Serrasalmidae Serrasalmus nigricans Spix & Agassiz, 1829 Fr native    Known from the Equatorial Brazil (Ref. 27142). Found in the Amazon River basin (Ref. 39031). - 
Serrasalmidae Serrasalmus odyssei Hubert & Renno, 2010 Fr native    16.72 cm SL male/unsexed    - 
Serrasalmidae Serrasalmus rhombeus (Linnaeus, 1766) Fr, Fi native  Piranha preta (Portuguese), Pirambeba (Portuguese), Piranha (Portuguese), Piranha branca (Portuguese), Piranha tinga (Portuguese)   41.50 cm SL male/unsexed  Found in the Amazon River basin and coastal rivers in the northeastern Brazil (Ref. 39031). Recorded from Machado river basin (Ref. 97589). + 
Serrasalmidae Serrasalmus scotopterus (Jardine, 1841) Fr native     - 
Serrasalmidae Serrasalmus serrulatus (Valenciennes, 1850) Fr native  Piranha (Portuguese)   19.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39031). + 
Serrasalmidae Serrasalmus spilopleura Kner, 1858 Fr, Fi, Or native  Piranha (Portuguese), Catirina (Portuguese), Curupeté (Portuguese), Palomita (Portuguese), Peixe prato (Portuguese), Peixe relógio (Portuguese), Pirambé (Portuguese), Pirambeba (Portuguese), Piranha amarela (Portuguese), Piranha doce (Portuguese), Piranha ferrujada (Portuguese), Piranha mafurá (Portuguese), Piranha preta (Portuguese) scarce (very unlikely) 26.00 cm TL male/unsexed 17.8 SL Recorded from Caracu and Sao Pedro streams, tributaries of the Paraná river (Ref. 39031) and Pircacicaba river (Ref. 50076). Also Ref. 31923. + 
Serrasalmidae Serrasalmus undulatus (Jardine, 1841) Fr native     - 
Rivulidae Simpsonichthys alternatus (Costa & Brasil, 1994) Fr endemic    3.88 cm SL male/unsexed  Known only from its type locality, a temporary pool at rio Paracatú floodplains, a western tributary at rio São Francisco, Minas Gerais (Ref. 49550). Also Ref. 27139, 36579. + 
Rivulidae Simpsonichthys boitonei Carvalho, 1959 Fr, Fi, Or endemic  Pira (Portuguese), Pirá brasília (Portuguese)   5.50 cm TL male/unsexed  Known from the upper Paraná River basin (Ref. 36579). Ref. 4537 classifies the status of this fish as endangered but indeterminant. Also Ref. 3881, 27139. + 
Rivulidae Simpsonichthys bokermanni (Carvalho & da Cruz, 1987) Fr endemic    6.50 cm TL male/unsexed  Known from Cachoeira River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Simpsonichthys cholopteryx Costa, Moreira & Lima, 2003 Fr native    Type locality, Rio Araguaia basin, on road MT 100, 31 km south of Alto Araguaia, 17°33'38.5"S, 53°18'33.1"W, Ribeirão do Sapo, Estado de Mato Grosso (Ref. 50838). - 
Rivulidae Simpsonichthys constanciae (Myers, 1942) Fr, Fi, Or endemic    6.00 cm TL male/unsexed  Occurs in the Rio de Janeiro State (Ref. 3881). Ref. 4537 classifies the status of this species as endangered but indeterminant. Also Ref. 27139. + 
Rivulidae Simpsonichthys delucai Costa, 2003 Fr native   2.80 cm SL male/unsexed  Known only from its type locality, a temporary pool near the city of Urucuia, rio Urucuia floodplains, a western tributary of rio São Francisco basin, Minas Gerais, MCP 28572 (holotype, 2.14 cm SL, male) (Ref. 49550). + 
Rivulidae Simpsonichthys fasciatus Costa & Brasil, 2006 Fr native    Known from the middle rio Paracatu drainage of the middle rio São Francisco basin (Ref. 57612). + 
Rivulidae Simpsonichthys gibberatus Costa & Brasil, 2006 Fr native    Known from the middle rio Paracatu drainage of the middle rio São Francisco basin (Ref. 57612). + 
Rivulidae Simpsonichthys margaritatus Costa, 2012 Fr native     - 
Rivulidae Simpsonichthys multiradiatus (Costa & Brasil, 1994) Fr endemic    4.64 cm SL male/unsexed  Known only from its type locality, a temporary pool in Brejinho de Nazaré, rio Tocantins floodplains, Estado do Tocantins (Ref. 49550). Also Ref. 27139. - 
Rivulidae Simpsonichthys nielseni Costa, 2005 Fr native    Known from São Franciso River basin (Ref. 56725). + 
Rivulidae Simpsonichthys nigromaculatus Costa, 2007 Fr native   2.56 cm SL male/unsexed ;2.19 cm SL female  Found only in temporary shallow canals in the floodplains of rio da Prata, rio Aporé drainage, upper rio Paraná basin. The habitat is an open area highly exposed to sunlight, locally known as Campo Úmido, a kind of vegetation typical of margins of streams draining the higher plateau lands of the Cerrado, the savannas of central Brazil (Ref. 75131). - 
Rivulidae Simpsonichthys ocellatus Costa, Nielsen & de Luca, 2001 Fr native   5.00 cm TL male/unsexed  Known from the Jequitinhonha River basin (Ref. 36579). Type locality, Estado de Minas Gerais (Ref. 30821). + 
Rivulidae Simpsonichthys parallelus Costa, 2000 Fr native    2.26 cm SL male/unsexed ;2.07 cm SL female  Occurs in the rio Paraná basin, central Brazil. Type locality, Estado de Goiás. - 
Rivulidae Simpsonichthys perpendicularis Costa, Nielsen & de Luca, 2001 Fr native    6.00 cm TL male/unsexed  Known from the Jequitinhonha River basin (Ref. 36579). Type locality, Estado da Bahia (Ref. 30821). + 
Rivulidae Simpsonichthys punctulatus Costa & Brasil, 2007 Fr native   2.91 cm SL male/unsexed ;2.40 cm SL female  Found in temporary canals at the floodplains of a tributary stream of the rio Bezerra, upper rio Paracatu drainage, rio São Francisco basin (Ref. 58746). + 
Rivulidae Simpsonichthys rosaceus Costa, Nielsen & de Luca, 2001 Fr native    5.00 cm TL male/unsexed  Known from the Pardo River basin in Bahia State (Ref. 36579). Type locality, Estado da Bahia (Ref. 30821). + 
Rivulidae Simpsonichthys rufus Costa, Nielsen & de Luca, 2001 Fr native    5.00 cm SL male/unsexed  Known from the São Francisco River basin (Ref. 36579). Type locality, Estado de Minas Gerais (Ref. 30821). + 
Rivulidae Simpsonichthys santanae (Shibatta & Garavello, 1992) Fr endemic    3.00 cm TL male/unsexed  Known from the Paraná River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Simpsonichthys similis Costa & Hellner, 1999 Fr native    6.00 cm TL male/unsexed  Known from the São Francisco River basin (Ref. 36579). Museum: temporary pool near Urucuia, road to São Ramão, rio Urucuia drainage, Estado de Minas Gerais, MZUSP 51834 (holotype of S. similis) (Ref. 36579). - 
Rivulidae Simpsonichthys stellatus (Costa & Brasil, 1994) Fr endemic    6.00 cm TL male/unsexed  Known from the middle São Francisco River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Simpsonichthys suzarti Costa, 2004 Fr native    Known from the floodplains of the lower Rio Pardo floodplains in northeastern Brazil (Ref. 53270). + 
Rivulidae Simpsonichthys trilineatus (Costa & Brasil, 1994) Fr endemic    6.00 cm TL male/unsexed  Known from the São Francisco River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Simpsonichthys virgulatus Costa & Brasil, 2006 Fr native    Known from the middle rio Paracatu drainage of the middle rio São Francisco basin, (Ref. 57612). + 
Rivulidae Simpsonichthys zonatus (Costa & Brasil, 1990) Fr endemic    5.00 cm TL male/unsexed  Also Ref. 27139. + 
Pimelodidae Sorubim elongatus Littmann, Burr, Schmidt & Isern, 2001 Fr native    32.20 cm SL male/unsexed    + 
Pimelodidae Sorubim lima (Bloch & Schneider, 1801) Fr, Fi native  Bico de pato (Portuguese), Lima shovelnose (English), Bico-de-pato (Portuguese), Boca de colher (Portuguese), Boca-de-chinelo (Portuguese), Braço de moça (Portuguese), Cabo de hacha paleta (Portuguese), Colhereiro (Portuguese), Donzela (Portuguese), Felimagro (Portuguese), Jerupoca (Portuguese), Jurupensem (Portuguese), Jurupensém (Portuguese), Jurupensén (Portuguese), Jurupesén (Portuguese), Jurupoca (Portuguese), Surubim lima (Portuguese), Tubajara (Portuguese)   54.20 cm TL male/unsexed 22.2 TL Known from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). Reported from the Uruguay River (Ref. 79585). Type locality: in flumine Maranham Brasiliae, ZMB 3185 (stuffed holotype of Sorubim lima; Amazonas, MNRJ 631 (holotype of Sorubim latirostris) (Ref. 57983). Also Ref. 36506. + 
Pimelodidae Sorubim maniradii Littmann, Burr & Buitrago-Suarez, 2001 Fr native    25.60 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36506). - 
Pimelodidae Sorubim trigonocephalus Miranda Ribeiro, 1920 Fr native  Arrowhead shovelnose (English) scarce (very unlikely) 50.70 cm SL male/unsexed  Known from Madeira and Tapajós River basins (Ref. 36506). Type locality, Mato Grosso, Porto Velho, rio Madeira, MNRJ 882 (holotype of Sorubim trigonocephalus, 31.7 cm SL) (Ref. 57983). - 
Pimelodidae Sorubimichthys planiceps (Spix & Agassiz, 1829) Fr, Fi native  Peixe lenhe (Portuguese), Chicote (Portuguese), Peixe lenha (Portuguese), Piraiapeani (Portuguese), Piraiapena (Portuguese), Pirambucu (Portuguese), Pirauaca (Portuguese), Pirauacá (Portuguese), Sorubim lenha (Portuguese), Surubim (Portuguese), Surubim chicote (Portuguese), Surubim lenha (Portuguese)   150 cm SL male/unsexed    + 
Loricariidae Spatuloricaria evansii (Boulenger, 1892) Fr native  Bode cachimbo papo mole (Portuguese), Bode fura fura (Portuguese)   28.20 cm SL male/unsexed  Known from the Paraguay (Ref. 36389) and Machado River basins (Ref. 97589). + 
Loricariidae Spatuloricaria nudiventris (Valenciennes, 1840) Fr native  Cascudo (Portuguese), Cascudo espada (Portuguese), Viega (Portuguese), Vieja (Portuguese), Viola (Portuguese)  20.35 cm SL male/unsexed  Known from the São Francisco River basin (Ref. 36389). + 
Loricariidae Spatuloricaria tuira Fichberg, Oyakawa & de Pinna, 2014 Fr native   46.00 cm TL male/unsexed  Known from the Rio Xingu and the Rio Tapajós drainages, both on the main river channels and their tributaries. Most specimens have been sampled after 2004, the year when construction of dams in the Xingu and Tapajos began. Spatuloricaria species may be preseumed extirpated from the entire impacted area of the dams, since species of the genus do not occur in still waters (Ref. 96500). + 
Loricariidae Spectracanthicus immaculatus Chamon & Rapp Py-Daniel, 2014 Fr, Or native  Naná (Portuguese), L363 (Portuguese)  8.22 cm SL male/unsexed  Found in rio Tapajós basin, near Itaituba and Pimental, Pará State (Ref. 95496). - 
Loricariidae Spectracanthicus murinus Nijssen & Isbrücker, 1987 Fr, Fi, Or endemic  Bicudo (Portuguese)  9.67 cm SL male/unsexed  Type locality of Spectracanthicus murinus, São Luis, rio Tapajós, near Itaituba and Santarém, Pará State (Ref. 95496). It is an important resource of ornamental fish and recognized by local fishermen and aquarists as 'bicudo' (or snouty) and is usually captured by diving with the aid of a compressor, a typical way to capture ornamental fishes (Ref. 95496). Also Ref. 6868, 36713. + 
Loricariidae Spectracanthicus punctatissimus (Steindachner, 1881) Fr, Or endemic   10.60 cm SL male/unsexed  Type locality of Chaetostomus punctatissimus, Pará. Known from Xingu River basin (Ref. 36713). an important resource of ornamental fish. It is also recognized as L016 and L030 by aquarists and ornamental fishermen and usually captured by diving with aid of a compressor, a usual way to capture ornamental fishes in Altamira, Pará (Ref. 95496). + 
Loricariidae Spectracanthicus tocantinensis Chamon & Rapp Py-Daniel, 2014 Fr native   9.33 cm SL male/unsexed  Found in the lower rio Tocantins, near Tucuruí and Jatobal in Pará (Ref. 95496). - 
Loricariidae Spectracanthicus zuanoni Chamon & Rapp Py-Daniel, 2014 Fr native  Acari bola branca (Portuguese), L020 (Portuguese), L354 (Portuguese)  24.00 cm TL male/unsexed  Found in therio Xingu basin, near Altamira and Belo Monte, Pará State (Ref. 95496). + 
Rivulidae Spectrolebias costai (Lazara, 1991) Fr native   4.00 cm TL male/unsexed  Known from Mato Grosso (Ref. 27139). Found in the Araguaia-Tocantins River basin (Ref. 36579). + 
Rivulidae Spectrolebias gracilis Costa & Amorim, 2018 Fr endemic   2.08 cm SL male/unsexed ;1.85 cm SL female  Type locality for Spectrolebias gracilis, Tocantins River, Tocantins state. - 
Rivulidae Spectrolebias inaequipinnatus (Costa & Brasil, 2008) Fr native   2.76 cm SL male/unsexed  Known only from a seasonal pool in the Tocantins River floodplains in central Brazil (Ref. 79814). - 
Rivulidae Spectrolebias reticulatus (Costa & Nielsen, 2003) Fr native   2.00 cm SL male/unsexed ;1.67 cm SL female  Type locality, Altamira, about 3°15'S, 52°20'W, Estado do Pará (Ref. 50838). + 
Rivulidae Spectrolebias semiocellatus Costa & Nielsen, 1997 Fr endemic    2.20 cm SL male/unsexed  Known only from the type locality, rio Formoso floodplains, rio Araguaia basin (Ref. 26131). Also Ref. 36579. + 
Characidae Spintherobolus ankoseion Weitzman & Malabarba, 1999 Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)  2.79 cm SL male/unsexed  Known from northen Santa Catarina to Paraná (Ref. 32783). Also Ref. 37055. + 
Characidae Spintherobolus broccae Myers, 1925 Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)   2.56 cm SL male/unsexed  Known from the lowlands around and to the east and west of the Baia de Guanabara, Rio de Janeiro and lowlands around Santos, São Paulo (Ref. 32783). Type locality: Hills behind Río de Janeiro, Brazil (Ref. 26282). Also Ref. 37055. - 
Characidae Spintherobolus leptoura Weitzman & Malabarba, 1999 Fr native  Lambari (Creole, Portuguese), Piabinha (Creole, Portuguese)  2.75 cm SL male/unsexed  Known from the lowlands around the rio Ribeira de Iguape, São Paulo. - 
Characidae Spintherobolus papilliferus Eigenmann, 1911 Fr native  Lambari (Creole, Portuguese), Piaba (Creole, Portuguese)   6.08 cm SL male/unsexed ;6.08 cm SL female  Known from the headwaters of the westward flowing rio Tietê (Ref. 32783). Museum: Alto da Serra, Rio Tiete basin, Paranapiacaba, Sao Paulo (Ref. 30296). Also Ref. 37055. - 
Trichomycteridae Stauroglanis gouldingi de Pinna, 1989 Fr native  Ghost candiru (English)  2.70 cm SL male/unsexed  Known from Daraá River, Negro River basin (Ref. 39970). + 
Hypopomidae Steatogenys duidae (La Monte, 1929) Fr native  Sarrapu (Portuguese)   20.90 cm TL male/unsexed    + 
Hypopomidae Steatogenys elegans (Steindachner, 1880) Fr native    29.40 cm TL male/unsexed  Occurs in the Amazon River Basin (Ref. 37053). Also Ref. 4537. - 
Hypopomidae Steatogenys ocellatus Crampton, Thorsen & Albert, 2004 Fr native   40.50 cm TL male/unsexed  Known from Lago Amaña and Lago Tefe in the Upper Amazon basin. - 
Trichomycteridae Stegophilus insidiosus Reinhardt, 1859 Fr native  Bagre (Portuguese), Candiru (Portuguese)   Known from São Francisco River basin (Ref. 39970). Type locality: Rio das Velhas, Brazil (Ref. 6868). - 
Trichomycteridae Stegophilus panzeri (Ahl, 1931) Fr native   4.10 cm SL male/unsexed  Known from the lower Amazon River basin (Ref. 39970). Also Ref. 6868. - 
Hypopomidae Stegostenopos cryptogenes Triques, 1997 Fr native   9.80 cm TL male/unsexed  Type locality: Igarapé (creek) Sirinau, right margin of R. Cuieiras, ca. 25 km from its mouth on R. Negro, ca. 2°70'S, 60°40'W, Brazil. - 
Pimelodidae Steindachneridion amblyurum (Eigenmann & Eigenmann, 1888) Fr, Thr endemic  Surubim (Portuguese)    Known from Jequitinhonha River basin (Ref. 36506). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 36506. Type locality: Jequitinhonha (Ref. 6868, 26282). - 
Pimelodidae Steindachneridion doceanum (Eigenmann & Eigenmann, 1889) Fr, Thr endemic  Surubim do doce (Portuguese)   42.00 cm SL male/unsexed  Regarded as threatened in the state of Minas Gerais (Ref. 26603). Type locality: Rio Doce (Ref. 36506). Also Ref. 6868. - 
Pimelodidae Steindachneridion melanodermatum Garavello, 2005 Fr native  Surubim-do-Iguaçu (Portuguese)  53.20 cm SL male/unsexed  Known from rio Iguaçu at the upper Paraná basin, border of Paraná and Santa Catarina States (Ref. 56935). - 
Pimelodidae Steindachneridion parahybae (Steindachner, 1877) Fr, Thr endemic  Bagre (Portuguese), Surubi (Portuguese), Surubim do paraíba (Portuguese)    Known from Paraíba do Sul and Jequitinhonha River basins (Ref. 36506). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Type locality: Rio Parahyba at Juiz de Fora; Rio Jequitinhonha, se. Brazil (Ref. 6868, 26282). + 
Pimelodidae Steindachneridion punctatum (Miranda Ribeiro, 1918) Fr native    69.70 cm SL male/unsexed  Found in the upper rio Paraná and rio Uruguay basin (Ref. 56935). - 
Pimelodidae Steindachneridion scriptum (Miranda Ribeiro, 1918) Fr, Fi, Aq, Thr native  Bocudo (Portuguese), Surubim (Portuguese), Suruvi (Portuguese)   100.00 cm TL male/unsexed  Known from the upper Paraná and Uruguay River basins (Ref. 58032). Type locality: Itaqui, Rio Grande do Sul (Ref. 36506). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 6868. + 
Curimatidae Steindachnerina amazonica (Steindachner, 1911) Fr native  Branquinha comum (Portuguese)   9.90 cm SL male/unsexed  Known from Rio Tocantins basin (Ref. 30554). Also Ref. 38013. - 
Curimatidae Steindachnerina bimaculata (Steindachner, 1876) Fr, Fi native  Branquinha (Portuguese), Saburu (Portuguese)   17.30 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). Also Ref. 12202. + 
Curimatidae Steindachnerina biornata (Braga & Azpelicueta, 1987) Fr native  Biru (Portuguese)   18.80 cm TL male/unsexed  Known from Atlantic coastal drainages of Rio Grande do Sul and Rio Uruguai in Santa Catarina (Ref. 30554). + 
Curimatidae Steindachnerina brevipinna (Eigenmann & Eigenmann, 1889) Fr native  Biru (Portuguese), Curimbatazinho (Portuguese)   22.60 cm TL male/unsexed 6.5 TL Known from Río Paraguay and Río Uruguay (Ref. 30554). + 
Curimatidae Steindachnerina conspersa (Holmberg, 1891) Fr native  Curimbatazinho (Portuguese)   12.80 cm SL male/unsexed    - 
Curimatidae Steindachnerina dobula (Günther, 1868) Fr native    16.30 cm SL male/unsexed  Known from the Amazon basin. + 
Curimatidae Steindachnerina elegans (Steindachner, 1875) Fr native  Biruba (Portuguese), Beiru (Portuguese), Biru (Portuguese), Mocinha (Portuguese), Piabuçu (Portuguese), Piabussu (Portuguese), Sabaru (Portuguese), Saburu (Portuguese), Saguiru (Portuguese), Sairu (Portuguese)   10.60 cm SL male/unsexed  Known from eastern Brazil in the Rio Pardo and Rio Jequitinhonha in Bahia and Minas Gerais, Rio Sao Francisco basin, and coastal rivers of the state of Bahia (Ref. 30554). Also Ref. 38013. + 
Curimatidae Steindachnerina fasciata (Vari & Géry, 1985) Fr native    9.60 cm SL male/unsexed  Known from the upper portions of the eastern drainages of the Madeira River basin (Ref. 30554) and Machado river (Ref. 97589). Type locality, Rio Romari near Nova Uniao, Municipality of Ouro Preto do Oeste, Terr. Rondônia, Brazil, MNRJ 11208 (holotype of C. fasciata, 8.96 cm SL) (Ref. 29122). Also Ref. 27925, 38013. - 
Curimatidae Steindachnerina gracilis Vari & Williams Vari, 1989 Fr native   7.30 cm SL male/unsexed  Known from the Tocantins River basin (Ref. 30554). Museum: Rio Araguaia, Arauna, Goiás, MZUSP 4847 (holotype of S. gracilis, 6.35 cm SL). Rio Tocantins, lagoons along the margin of river near Tacuruí, MZUSP 38592 (Ref. 27925). Also Ref. 38013. - 
Curimatidae Steindachnerina guentheri (Eigenmann & Eigenmann, 1889) Fr native  Piaba (Portuguese), Saburu (Portuguese)   11.10 cm SL male/unsexed  Known from the Amazon (Ref. 38013), Machado (Ref. 97589) and Acre River basins (Ref. 97592). + 
Curimatidae Steindachnerina hypostoma (Boulenger, 1887) Fr native    9.80 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). - 
Curimatidae Steindachnerina insculpta (Fernández-Yépez, 1948) Fr, Fi native  Fernete (Portuguese)   16.10 cm TL male/unsexed ;19.30 cm TL female 4.7 TL Known from the upper Paraná River basin (Ref. 38013). Recorded from Piracicaba river (Ref. 50076). Museum: Rio Tatuhy, Sao Paulo, MZUSP 1376 (Ref. 27925). + 
Curimatidae Steindachnerina leucisca (Günther, 1868) Fr native  Saburu (Portuguese)   15.10 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). - 
Curimatidae Steindachnerina notograptos Lucinda & Vari, 2009 Fr native   10.63 cm SL male/unsexed  Type locality, Tocantins, Paranã, Rio Palmas, MCP 42579 (holotype of Steindachnerina notograptos, 8.98 cm SL). Distributed in the middle portions of Rio Tocantins drainage in central Brazil (Ref. 80500). + 
Curimatidae Steindachnerina notonota (Miranda Ribeiro, 1937) Fr native  Piabussú (Portuguese), Saburú (Portuguese)   11.00 cm TL male/unsexed  Known from coastal rivers of northeastern Brazil (Ref. 30554). Also Ref. 38013. + 
Curimatidae Steindachnerina planiventris Vari & Williams Vari, 1989 Fr native    8.70 cm SL male/unsexed  Known from Negro, Branco, and middle portions of the Amazon River basins (Ref. 38013). Museum: near the mouth of Rio Machado, Rondônia, MZUSP 38587 (holotype of S. planiventris, 6.57 cm SL) (Ref. 27925). - 
Curimatidae Steindachnerina pupula Vari, 1991 Fr native    16.77 cm TL male/unsexed  Found in Acre river (Ref. 97592). - 
Curimatidae Steindachnerina quasimodoi Vari & Williams Vari, 1989 Fr native   12.30 cm SL male/unsexed  Known from the Amazon River (Ref. 38013). - 
Curimatidae Steindachnerina seriata Netto-Ferreira & Vari, 2011 Fr native   8.31 cm SL male/unsexed  Type locality, Pará , Novo Progresso, Rio Jamanxim basin of Rio Tapajo´ s system, near bridge along highway BR 163, south of Vila Mil, MZUSP 97569 (holotype of Steindachneria seriata, 7.89 cm SL) (Ref. 88964). + 
Curimatidae Steindachnerina varii Géry, Planquette & Le Bail, 1991 Fr native   9.40 cm SL male/unsexed  Present in the Oyapock River which forms the border between French Guiana and Brazil (Ref. 12225). - 
Rivulidae Stenolebias bellus Costa, 1995 Fr endemic   3.00 cm TL male/unsexed  Known from the Paraguay River basin (Ref. 36579). - 
Rivulidae Stenolebias damascenoi (Costa, 1991) Fr endemic   4.00 cm TL male/unsexed  Known from the Paraguay River basin (Ref. 36579). Also Ref. 27139. - 
Trichomycteridae Stenolicmus ix Wosiacki, Coutinho & de Assis Montag, 2011 Fr native   1.90 cm SL male/unsexed   - 
Apteronotidae Sternarchella calhamazon Lundberg, Coz Fernandes, Campos da Paz & Sullivan, 2013 Fr native  abundant (always seen in some numbers) 18.54 cm TL male/unsexed  Known from the Amazon basin (Ref. 93342). - 
Apteronotidae Sternarchella duccis (Lundberg, Cox Fernandes & Albert, 1996) Fr native   22.60 cm TL male/unsexed  Known from the Rio Iça to the Rio Trombetas and from the Rio Negro to the Rio Branco (Ref. 13085). Also Ref. 36886. - 
Apteronotidae Sternarchella raptor (Lundberg, Cox Fernandes & Albert, 1996) Fr native   19.90 cm TL male/unsexed  Type locality of Magosternarchus raptor, Amazonas, río Solimões, 17 km downriver from confluence of río Purus (Ref. 126780). Known from lower Rio Jutaí to Rio Xingú and from Rio Negro to Rio Branco (Ref. 13085). Also Ref. 36886. - 
Apteronotidae Sternarchella rex Evans, Crampton & Albert, 2017 Fr native   40.40 cm TL male/unsexed  Type locality of S. rex, Brazil, Tefé, Mamirauá Lake System, Paraná Maiana station A (Ref. 126780). - 
Apteronotidae Sternarchella schotti (Steindachner, 1868) Fr native  Sarapó (Portuguese)   40.00 cm TL male/unsexed  Type locality of Sternarchus schotti, near the mouth of rio Negro Manaus (Ref. 126780). Found in the Amazon River basin (Ref. 36886). + 
Apteronotidae Sternarchella sima Starks, 1913 Fr native    40.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). - 
Apteronotidae Sternarchogiton labiatus de Santana & Crampton, 2007 Fr native   21.40 cm TL male/unsexed  Type locality, Município de Tefé, Toco Preto, Rio Tefé, Amazonas, MCP 37544 (holotype of Sternarchogiton labiatus, 10.4 cm SL, female). Also known from one locality in the lower Rio Negro listed in Cox-Fernandes (Ref. 75769). - 
Apteronotidae Sternarchogiton nattereri (Steindachner, 1868) Fr native    25.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). - 
Apteronotidae Sternarchogiton porcinum Eigenmann & Allen, 1942 Fr native   30.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). - 
Apteronotidae Sternarchogiton preto de Santana & Crampton, 2007 Fr native    21.30 cm SL male/unsexed ;21.70 cm SL female  Known from the Amazon River basin. Type locality, Município de Tefé, Toco Preto, Rio Tefé, Amazonas, MCP 37553 (holotype of Sternarchogiton preto, 19.8 cm SL, male) (Ref. 75769). - 
Apteronotidae Sternarchogiton zuanoni de Santana & Vari, 2010 Fr native   17.80 cm TL male/unsexed   - 
Apteronotidae Sternarchorhamphus muelleri (Steindachner, 1881) Fr native   45.50 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). - 
Apteronotidae Sternarchorhynchus axelrodi de Santana & Vari, 2010 Fr native   60.00 cm TL male/unsexed  Type locality, Goiás: Município de Minaçu/Cavalcante, Rio Tocantins, at future site of Usina Hidroeléctrica Serra da Mesa, MNRJ 31279 (holotype of Sternarchorhynchus axelrodi, 44.4 cm TL, male). Collected from the Amazon Basin, Rio Tocantins (upper and lower portions of that river system) Ref. 84053). - 
Apteronotidae Sternarchorhynchus britskii Campos-da-Paz, 2000 Fr native  Ituí (Portuguese)   26.10 cm TL male/unsexed  Type locality, Mato Grosso do Sul: Rio Paraná, at Ilha Solteira dam, cofferdam at right margin of river, MZUSP 52923 (holotype of Sternarchorhynchus britskii, 27.2 cm TL). Known only from the upper portion of Río Paraná basin in the states of Mato Grosso do Sul, Minas Gerais, and São Paulo (Ref. 84053). Also Ref. 36886. - 
Apteronotidae Sternarchorhynchus caboclo de Santana & Nogueira, 2006 Fr native   22.60 cm TL male/unsexed  Type locality, Roraima: Rio Branco basin, Rio Mucajaí, below Cachoeira Paredão 2, INPA 22894 (holotype of Sternarchorhynchus caboclo, 22.5 cm TL, male) (Ref. 84053). Known only from the Rio Mucajaí in Roraima (Ref. 56957). - 
Apteronotidae Sternarchorhynchus chaoi de Santana & Vari, 2010 Fr native    16.40 cm TL male/unsexed  Type locality, Rondônia: Rio Jamari, Porto Velho, canal de desvio da (diversion canal of ) UHE (Usina Hidroeléctica) Samuel, INPA 28357 (holotype of Sternarchorhynchus chaoi, 15.5 cm Tl, presumably male). Known only from Rio Jamari basin of the state of Rondônia (Ref. 84053). - 
Apteronotidae Sternarchorhynchus cramptoni de Santana & Vari, 2010 Fr native    33.10 cm TL male/unsexed ;29.00 cm TL female  Type locality, Amazonas, Rio Solimões, downstream from mouth of Río Purus, INPA 28376 (formerly FMNH 115489) (holotype of Sternarchorhynchus cramptoni, 29.0 cm TL, female). It is widely distributed along the mainstream of the Amazon River from the region of Iquitos in north-eastern Peru downstream to the Rio Trombetas, a left bank tributary of the Amazon in the state of Pará, (Ref. 84053). - 
Apteronotidae Sternarchorhynchus curumim de Santana & Crampton, 2006 Fr native   18.10 cm TL female  Type locality, Amazonas: Rio Tefé, Toco Preto, Município de Tefé, MCP 38304 (holotype of Sternarchorhynchus curumim, 16.3 cm TL, female) (Ref. 84053). Known from the lowland Amazon basin (Ref. 57455). - 
Apteronotidae Sternarchorhynchus curvirostris (Boulenger, 1887) Fr questionable   40.60 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). No specimens discussed in the revision (Ref. 84053). - 
Apteronotidae Sternarchorhynchus goeldii de Santana & Vari, 2010 Fr native    30.60 cm TL male/unsexed  Type locality, Amazonas, Rio Purus, INPA 28378 (holotype of Sternarchorhynchus goeldii, 30.6 cm TL) (Ref. 84053). - 
Apteronotidae Sternarchorhynchus hagedornae de Santana & Vari, 2010 Fr native    24.90 cm TL male/unsexed ;20.60 cm TL female   - 
Apteronotidae Sternarchorhynchus higuchii de Santana & Vari, 2010 Fr native   24.60 cm TL male/unsexed  Amazonas: Rio Uatumã, Cachoeira do Miriti, Presidente Figueredo, INPA 28358 (holotype of Sternarchorhynchus higuchii, 24.6 cm TL, male). Collected from Cachoeira do Miriti and Cachoeira do Morena in the Rio Uatumã in the eastern portions of Amazonas (Ref - 
Apteronotidae Sternarchorhynchus inpai de Santana & Vari, 2010 Fr native   22.20 cm TL male/unsexed  Type locality, Pará: Rio Mapuera, Cachoeira Porteira, last fall before Rio Trombetas, INPA 22895 (holotype of Sternarchorhynchus inpai, 19.1 cm TL) (Ref. 84053). - 
Apteronotidae Sternarchorhynchus jaimei de Santana & Vari, 2010 Fr native   20.00 cm TL female  Type locality, Amazonas: Rio Uatumã, Cachoeira do Miriti, Presidente Figueredo, INPA 28359 (holotype of Sternarchorhynchus jaimei, 20.0 cm TL, maturing female) (Ref. 84053). - 
Apteronotidae Sternarchorhynchus kokraimoro de Santana & Vari, 2010 Fr native   19.70 cm TL male/unsexed ;17.10 cm TL female 19.7 TL Type locality, Pará: Rio Xingu, Cachoeira de Kaituká, at Altamira, INPA 28360 (holotype of Sternarchorhynchus kokraimoro, 19.7 cm TL, mature male) (Ref. 84053). - 
Apteronotidae Sternarchorhynchus mareikeae de Santana & Vari, 2010 Fr native   19.20 cm TL male/unsexed ;13.50 cm TL female  Type locality, Pará: Rio Trombetas, Cachoeira Porteira, last fall before Rio Trombetas, INPA 22896 (holotype of Sternarchorhynchus mareikeae, 19.2 cm TL, male). Known only from its type locality (Ref. 84053). - 
Apteronotidae Sternarchorhynchus mesensis Campos-da-Paz, 2000 Fr native   24.90 cm TL male/unsexed  Type locality, Goiás, Río Tocantins (upper Río Tocantins region), at Serra de Mesa dam, municípios Minaçu/Uruaçu (‘Minaçu/Cavalcante'), MNRJ 17591 (holotype of Sternarchorhynchus mesensis). Known from sites in the upper Rio Tocantins system and has been collected in caves of the São Domingos karst region (Ref. 84053). Also Ref. 36352, 36886. - 
Apteronotidae Sternarchorhynchus mormyrus (Steindachner, 1868) Fr native   54.00 cm TL male/unsexed  Type locality, Marabitanos (= Río Negro, north of Marabitanas at foot of Cocui mountains) (Ref. 84053). Found in the Amazon River basin (Ref. 36886). Also Ref. 36352. - 
Apteronotidae Sternarchorhynchus oxyrhynchus (Müller & Troschel, 1849) Fr native  Ituí (Portuguese), Lampreia (Portuguese), Lampreia amarela (Portuguese), Tuiu (Portuguese), Tuvira (Portuguese)  47.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). + 
Apteronotidae Sternarchorhynchus retzeri de Santana & Vari, 2010 Fr native    38.20 cm TL female  Type locality, Amazonas: Rio Tefé, Toco Preto, Tefé, MCP 41636 (holotype of Sternarchorhynchus retzeri, 37.2 cm TL, sexually dimorphic male). Broadly distributed across the Amazon basin from the Rio Iça basin in the western portions of Amazonas to the Rio Trombetas in Pará (Ref. 84053). - 
Apteronotidae Sternarchorhynchus roseni Mago-Leccia, 1994 Fr native   41.70 cm TL male/unsexed  Found in the Amazon River basin (Ref. 36886). Also Ref. 36352. - 
Apteronotidae Sternarchorhynchus schwassmanni de Santana & Vari, 2010 Fr native   11.58 cm TL male/unsexed ;9.85 cm TL female  Type locality, Pará: Rio Araguaia, small stream between São João do Araguaia (5°23′S, 48°46′W) and São Bento (5°28′S, 48°20′W), MZUSP 95633 (holotype of Sternarchorhynchus schwassmanni, 9.85 cm TL, female; formerly MHNG 2566.093, in part) (Ref. 84053). - 
Apteronotidae Sternarchorhynchus severii de Santana & Nogueira, 2006 Fr native   16.90 cm TL male/unsexed  Type locality, Roraima, Rio Mucajaí, below Cachoeira Paredão, INPA 22893 (holotype of Sternarchorhynchus severii, 16.1 cm TL, male). Known only from its type locality (Ref. 84053). Also Ref. 56957. - 
Apteronotidae Sternarchorhynchus starksi de Santana & Vari, 2010 Fr native   37.40 cm TL male/unsexed  Type locality, Pará: Rio Pará between Rio Boa Vista and Rio Tocantins, between towns of Boa Vista and Abaetetuba, INPA 28377 (holotype of Sternarchorhynchus starksi, 23.1 cm TL; formerly FMNH 115485). Samples with definite locality information came from the easternmost portions of the Amazon basin or were purchased in the fish market at Belém (Starks, 1913: 4, 23; cited as S. curvirostris; given the fishing and transportation technology at this time, it is likely that those market samples were captured close to that city in the lowermost portion of the Amazon River) (Ref. 84053). - 
Apteronotidae Sternarchorhynchus villasboasi de Santana & Vari, 2010 Fr native   13.60 cm TL male/unsexed ;13.50 cm TL female  Type locality, Pará: Rio Xingu, Cachoeira de Kaituká, at Altamira, INPA 28361 (holotype of Sternarchorhynchus villaboasi, 13.5 cm TL, mature female) (Ref. 84053). - 
Sternopygidae Sternopygus astrabes Mago-Leccia, 1994 Fr native   23.30 cm TL male/unsexed   - 
Sternopygidae Sternopygus branco Crampton, Hulen & Albert, 2004 Fr native  Sarapó branco (Portuguese)  49.20 cm TL male/unsexed  Known only from the main channel of the Amazon River between its confluences with the Rios Japurá and Negro from the lower 100 km of the main channel of the Rio Negro (Ref. 55493). - 
Sternopygidae Sternopygus castroi Triques, 2000 Fr native   19.60 cm TL male/unsexed  Found in the Negro River basin (Ref. 39524). - 
Sternopygidae Sternopygus macrurus (Bloch & Schneider, 1801) Fr native  Tuvira (Portuguese), Itui (Portuguese), Ituí (Portuguese), Lampreia preta (Portuguese), Sarapó (Portuguese), Sarapó-limpo (Portuguese), Sarapú (Portuguese)   141 cm TL male/unsexed  Occurs in the Amazon and Sao Francisco River. Recorded from Córrego Barreiro (Ref. 53011), Machado (Ref. 97589) and Acre River basins (Ref. 97592). + 
Sternopygidae Sternopygus obtusirostris Steindachner, 1881 Fr native  Ituí (Portuguese), Lampreia (Portuguese), Tuvira (Portuguese)   56.00 cm TL male/unsexed  Occurs in Central Amazon from localities adjacent to the main stem of the Amazon river between Tefé, Amazonas and Obidos, Pará; also known from the lower and middle Rio Negro (Ref. 52797). - 
Sternopygidae Sternopygus xingu Albert & Fink, 1996 Fr native   52.50 cm TL male/unsexed  Found in the Xingu and lower Tocantins River basins (Ref. 39524). - 
Characidae Stethaprion crenatum Eigenmann, 1916 Fr native    8.50 cm SL male/unsexed    - 
Characidae Stethaprion erythrops Cope, 1870 Fr native   8.80 cm SL male/unsexed  Known from the Amazon River basin (Ref. 36891). + 
Characidae Stichonodon insignis (Steindachner, 1876) Fr native   8.00 cm TL male/unsexed  Found in the Amazon River basin (Ref. 38376). - 
Ophichthidae Stictorhinus potamius Böhlke & McCosker, 1975 Fr native   34.50 cm TL male/unsexed  Known from the lower Tocantins River of the Amazon River basin and Bahia in northeastern Brazil (Ref. 58455). Type locality: Freshwater pool of Rio Tocantin near Tucuruí, Pará (Ref. 26262). - 
Belonidae Strongylura marina (Walbaum, 1792) Fr, Br, M native  Agulha (Portuguese), Agulhão (Portuguese), Agulhinha (Portuguese)  111 cm TL male/unsexed  Located at the southernmost tip of the Bombinhas peninsula, southern Brazil (Ref. 55758). Also Ref. 26340, 79012. + 
Loricariidae Sturisoma barbatum (Kner, 1853) Fr native  Rapa-canoa (Portuguese), Acari (Portuguese), Cari (Portuguese)  28.00 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 36389). + 
Loricariidae Sturisoma brevirostre (Eigenmann & Eigenmann, 1889) Fr native   20.70 cm SL male/unsexed  Known from the Içá River basin (Ref. 36389). - 
Loricariidae Sturisoma lyra (Regan, 1904) Fr native    25.00 cm TL male/unsexed  Known from the Juruá River basin (Ref. 36389). - 
Loricariidae Sturisoma robustum (Regan, 1904) Fr native  Acari (Portuguese), Bode bico fino (Portuguese), Bode cachimbo furão (Portuguese), Cari (Portuguese), Rapa-canoa (Portuguese)   25.00 cm SL male/unsexed  Known from the La Plata River basin (Ref. 36389). + 
Loricariidae Sturisoma rostratum (Spix & Agassiz, 1829) Fr native  Acará pedra (Portuguese), Acari roncador (Portuguese), Acarí roncador (Portuguese), Acary roncador (Portuguese), Peixe pedra (Portuguese), Roncador (Portuguese), Taóca (Portuguese)   19.00 cm male/unsexed    + 
Characidae Stygichthys typhlops Brittan & Böhlke, 1965 Fr endemic    2.36 cm SL male/unsexed  Type locality, Minas Gerais, município de Jaaíba, ANSP 100891 (holotype of Stygichthys typhlops, 2.3 cm SL). Rediscovered in the area after almost 50 years after its first discovery; 34 specimens were collected in 2 shallow hand-dug wells. Collected from two shallow wells separated by 4·5 km and c. 13 km south-west of the town of Jaíba; the well at Fazenda do Seu Roque is still occasionally used as a source of water for cattle, while the shallow well at Fazenda do Lajeado is abandoned (Ref. 84216). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 27297. - 
Cichlidae Symphysodon aequifasciatus Pellegrin, 1904 Fr, Fi native  Acará disco (Portuguese), Acará disco azul (Portuguese), Acará disco castanho (Portuguese), Acará disco marron (Portuguese), Acará disco verde (Portuguese)   13.70 cm SL male/unsexed  Known from the Amazon River basin in tributaries along the Solimões-Amazon River to the Tocantins River basin (Ref. 36377). Known from near Belem do Para, Brazil (Ref. 12251). + 
Cichlidae Symphysodon discus Heckel, 1840 Fr endemic  Moreré (Portuguese), Acará bararuá (Portuguese), Acará disco (Portuguese), Acará disco comum (Portuguese), Acará-moreré (Portuguese), Morerê (Portuguese), Peixe disco (Portuguese)   12.30 cm SL male/unsexed  Known from the Amazon River basin in Brazil, near the mouth of the Negro River, in the lower Abacaxis River, and in the lower Trombetas River (Ref. 36377). In 1993, 144,561 specimens were exported from Manaus for the aquarium trade; this may threaten the persistence of the species in the wild (Ref. 40602). + 
Cichlidae Symphysodon tarzoo Lyons, 1959 Fr native   16.30 cm SL male/unsexed  Found in Rio Jutaí, Amazonas. Recorded from Madeira River (Ref. 57706). + 
Anostomidae Synaptolaemus cingulatus Myers & Fernández-Yépez, 1950 Fr native     + 
Synbranchidae Synbranchus lampreia Favorito, Zanata & Assumpção, 2005 Fr native    38.00 cm TL male/unsexed  Known from rio Goiapi, Marajó Island in Pará, northern Brazil (Ref. 56782). + 
Synbranchidae Synbranchus madeirae Rosen & Rumney, 1972 Fr native    100.00 cm TL male/unsexed    - 
Synbranchidae Synbranchus marmoratus Bloch, 1795 Fr, Fi native  Mussum (Portuguese), Enguia (Portuguese), Enguia da água doce (Portuguese), Enguia-d'água-doce (Portuguese), Moçu (Portuguese), Muçu (Portuguese), Muçum (Portuguese), Munsum (Portuguese), Peixe-cobra (Portuguese), Piramboia (Portuguese), Pirambóia (Portuguese)   150 cm TL male/unsexed  Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076) and Pircacicaba river (Ref. 50076). Also reported from the Uruguay River (Ref. 79585) and Machado River basin (Ref. 97589). Also Ref. 81048. + 
Syngnathidae Syngnathus scovelli (Evermann & Kendall, 1896) Fr, Br, M native  Peixe-cachimbo (Portuguese)  18.30 cm SL male/unsexed 7.7 TL  + 
Cichlidae Taeniacara candidi Myers, 1935 Fr endemic    3.30 cm SL male/unsexed ;5.00 cm TL female  Known from the Amazon River basin in the lower Negro River and along the Amazon River to the Tapajós River (Ref. 36377). Type locality: Middle Amazon, Brazil (Ref. 12965). + 
Tarumaniidae Tarumania walkerae de Pinna, Zuanon, Rapp Py-Daniel & Petry, 2017 Fr native   15.12 cm SL male/unsexed  Type locality of Tarumania walkerae, marginal pool of Igarapé Tarumã-Mirim (tributary to Rio Negro). Endemic to the Rio Negro basin, from the Rio Tarumã-Mirim, tributary to the Rio Negro near the city of Manaus, and from the Anavilhanas archipelago, on the main Rio Negro (Ref. 116356). - 
Auchenipteridae Tatia akroa Souza e Souza, Sarmento-Soares, Canto & Ribeiro, 2020 Fr native   3.84 cm SL male/unsexed  Type locality of Tatia akroa: Rio Tocantins basin, Rio Perdida (Ref. 128482). - 
Auchenipteridae Tatia aulopygia (Kner, 1858) Fr native    15.90 cm SL male/unsexed  Known from the Madeira River drainage of the Amazon basin (Ref. 79512). Recorded from Machado river basin (Ref. 97589). + 
Auchenipteridae Tatia bockmanni (Sarmento-Soares & Buckup, 2005) Fr native   4.80 cm SL male/unsexed  Known from São Francisco river basin in Minas Gerais and Bahia. Type locality, downstream from Três Marias Dam, MZUSP 82803 (holotype of Glanidium bockmanni, 4.8 cm SL, male) (Ref. 56311). - 
Auchenipteridae Tatia boemia Koch & Reis, 1996 Fr, Thr endemic  Boa noite (Portuguese)   6.90 cm SL male/unsexed  Known from the upper reaches of rio Uruguay drainage (Ref. 26675). Also Ref. 37098. Status of threat: Endangered (Ref. 79585). + 
Auchenipteridae Tatia britskii (Sarmento-Soares & Birindelli, 2015) Fr native   3.92 cm SL male/unsexed  Occurs in the rio Paraná basin near Ilha Solteira, where now is the reservoir of the UHE Ilha Solteira, in the upper rio Paraná basin, São Paulo (Ref. 103263). - 
Auchenipteridae Tatia brunnea Mees, 1974 Fr native   11.60 cm SL male/unsexed 7 SL Known from Negro and Trombetas River drainages, and at a single locality in central Amazon basin (Ref. 79512). + 
Auchenipteridae Tatia caxiuanensis Sarmento-Soares & Martins-Pinheiro, 2008 Fr native   4.07 cm SL male/unsexed 2.93 SL Known only from the type locality, Curuá river, lower Amazon basin, about 330 km southwest from the city of Belém, Pará (Ref. 79512) - 
Auchenipteridae Tatia dunni (Fowler, 1945) Fr native    12.00 cm SL male/unsexed  Known from the central Amazon River (Ref. 79512), Purus and Acre River basins (Ref. 97592). + 
Auchenipteridae Tatia gyrina (Eigenmann & Allen, 1942) Fr native    4.20 cm SL male/unsexed  Known from the Amazon River (Ref. 79512). + 
Auchenipteridae Tatia intermedia (Steindachner, 1877) Fr native    12.00 cm SL male/unsexed  Known from the Araguaia, Tocantins, Xingu and Capim rivers, tributaries of the lower Amazon (Ref. 79512). Also Ref. 6868, 37098. + 
Auchenipteridae Tatia jaracatia Pavanelli & Bifi, 2009 Fr native    6.63 cm SL male/unsexed  Found in the lower rio Iguaçu basin, upstream from the Iguaçu falls, southern Brazil (Ref. 81205). - 
Auchenipteridae Tatia neivai (Ihering, 1930) Fr native  Jundiá (Portuguese)   8.21 cm SL male/unsexed  Known from the upper Paraguay river in the Pantanal of Mato Grosso, upper Paraná river and upper Paraíba do Sul river. Found in several tributaries of the upper Paraná river such as the Grande river in Minas Gerais, the Tietê and Paranapanema rivers in São Paulo, and the Tibagi river in Paraná. A single record from the São Francisco river is uncertain.(Ref. 79512). Occurrence in the Uruguay River (Ref. 79585) needs further confirmation as this is outside its distributional range. + 
Auchenipteridae Tatia nigra Sarmento-Soares & Martins-Pinheiro, 2008 Fr native   11.68 cm SL male/unsexed  Found in central Amazon, in the Uatumã and Trombetas river drainages, northern tributaries of the Amazon river (Ref. 79512). + 
Auchenipteridae Tatia punctata Mees, 1974 Fr native    4.50 cm SL male/unsexed    + 
Auchenipteridae Tatia reticulata Mees, 1974 Fr native    3.98 cm SL male/unsexed   + 
Auchenipteridae Tatia simplex Mees, 1974 Fr native   4.77 cm SL male/unsexed  Known from the Das Mortes River in Mato Grosso (Ref. 37098). Found in Xaventina House Beach, Rio das Mortes in Mato Grosso (Ref. 6868). - 
Auchenipteridae Tatia strigata Soares-Porto, 1995 Fr native   11.68 cm SL male/unsexed  Found in the Amazon (Ref. 26667). Also Ref. 79512. + 
Heptapteridae Taunayia bifasciata (Eigenmann & Norris, 1900) Fr endemic  Bagre (Portuguese), Bagrinho (Portuguese)   14.00 cm SL male/unsexed  Known from upper Paraíba do Sul and Tietê River basins (Ref. 36914). Type locality: S. Paulo, Brazil (considering its known distribution, type locality may be restricted to the headwaters of the Paraíba do Sul and Tietê River basins, São Paulo, Ref. 36914). + 
Cichlidae Teleocichla centisquama Zuanon & Sazima, 2002 Fr native  Slender pike cichlid (English)   4.00 cm SL male/unsexed  Known from the Amazon River basin in the Xingu River drainage around Altamira (Ref. 36377). Type locality, Furo do Zé Pinheiro, Rio Xingu, Pará (Ref. 46528). + 
Cichlidae Teleocichla centrarchus Kullander, 1988 Fr native    6.00 cm SL male/unsexed  Known from Amazon River basin in the Xingu River drainage at Cachoeira von Martius (Ref. 36377). Type locality: Rio Xingù, Cachoeira von Martius, Haut Xingù, État du Mato Grosso (Ref. 34233). + 
Cichlidae Teleocichla cinderella Kullander, 1988 Fr native    5.40 cm SL male/unsexed  Known from the lower Tocantins River basin of the Amazon River basin (Ref. 36377). Type locality: State of Pará,: R. Tocantins, Tucurui, jusante de represa, poços (Ref. 34233). Its original rapids habitat is now under the huge lake formed by the Tucuruí hydroelectric reservoir (status of the species presently unknown) (Ref. 46528). Maybe threatened by extinction due to its restricted distribution in the rapids of Rio Tocantins, a biotope currently destroyed by hydroelectric power plants (Ref. 85327). + 
Cichlidae Teleocichla gephyrogramma Kullander, 1988 Fr native    4.60 cm SL male/unsexed  Known from the Amazon River basin in the Xingu River drainage at Cachoeira von Martius (Ref. 36377). Type locality: Brésil, Rio Xingù, Cachoeira von Martius, Haut Xingù, État du Mato Grosso (Ref. 34233). Also Ref. 12251. - 
Cichlidae Teleocichla monogramma Kullander, 1988 Fr native    6.30 cm SL male/unsexed  Known from the Amazon River basin in the Xingu River drainage at Cachoeira von Martius (Ref. 36377). Type locality: Brésil, Rio Xingù, Cachoeira von Martius, Haut Xingù, État du Mato Grosso (Ref. 34233). + 
Cichlidae Teleocichla preta Varella, Zuanon, Kullander & López-Fernández, 2016 Fr, Or endemic   24.50 cm TL male/unsexed  Type locality of Teleocichla preta, Pará State, Altamira, rapids of Rio Xingu in front of Praia do Besouro. Occurs in Rio Xingu between Cachoeira Chadasinho upstream of São Félix do Xingu and Cachoeira do Jericoá at Volta Grande do Xingu downstream of Altamira, Pará State. Also known from the lower portion of the Rio Iriri, the largest tributary of the Rio Xingu (Ref. 108975). + 
Cichlidae Teleocichla prionogenys Kullander, 1988 Fr native    5.70 cm SL male/unsexed ;5.60 cm SL female  Known from the Amazon River basin in the Tapajós River at São Luis (Ref. 36377). Type locality: Brazil, State of Pará: Rio Tapajos, São Luis, acima de Itaituba, pedral (Ref. 34233). Also Ref. 12251. - 
Cichlidae Teleocichla proselytus Kullander, 1988 Fr native    5.70 cm SL male/unsexed  Known from the Amazon River basin, in the Tapajós River at São Luis (Ref. 36377). Type locality: Brazil, State of Pará: Rio Tapajos, São Luis, acima de Itaituba, pedral (Ref. 34233). Also Ref. 12251. + 
Cichlidae Teleocichla wajapi Varella & Moreira, 2013 Fr native   8.78 cm SL male/unsexed  Known from rio Jari and two of its tributaries, rio Iratapuru and rio Pacanari (Ref. 93336). - 
Apteronotidae Tembeassu marauna Triques, 1998 Fr native    19.60 cm TL male/unsexed  Occurs in Rio Paraná, Mato Grosso do Sul (Ref. 50581). Also Ref. 35431. - 
Doradidae Tenellus leporhinus (Eigenmann, 1912) Fr native   17.30 cm SL male/unsexed   + 
Doradidae Tenellus ternetzi (Eigenmann, 1925) Fr native   12.86 cm SL male/unsexed  Known from Tapajós, Santarém (Ref. 6868). Found in the Amazon River (Ref. 37054). + 
Doradidae Tenellus trimaculatus (Boulenger, 1898) Fr native    11.40 cm SL male/unsexed  Found in the Rio Jurua (Ref. 6868). + 
Characidae Tetragonopterus anostomus Silva & Benine, 2011 Fr native   12.90 cm TL male/unsexed 4.65 SL Type localities of Tetragonopterus anostomus, Nova Crixás, rio Preto, rio Araguaia basin, Goiás State and Tetragonopterus akamai, Rio Tocantins drainage. Reported from State of Goiás, Nova Crixás, and lagoa marginal at the municipality of Cocalinho, Mato Grosso, rio Araguaia basin, central Brazil (Ref. 87186) and in the upper and middle portions of the rio Tocantins drainage (Ref. 96868). - 
Characidae Tetragonopterus araguaiensis Silva, Melo, Oliveira & Benine, 2013 Fr native   6.25 cm SL male/unsexed  Type locality of Tetragonopterus araguaiensis, Goiás, Aruanã, Rio Araguaia, Amazon basin (Ref. 124043). Found in the middle portion of the Rio Araguaia in the municipalities of Aragarças, Aruaña, Cocalinho and Santa Terezinha, central Brazil (Ref. 93280). - 
Characidae Tetragonopterus argenteus Cuvier, 1816 Fr native  Sardinha matupiri (Portuguese), Lambari prata (Portuguese), Lambari prateado (Portuguese), Pataca (Portuguese), Sauá (Portuguese)   11.20 cm SL male/unsexed  Type locality of Tetragonopterus sawa, 'rio Crixas qui se jette dans L’Araguaia' (Ref. 124043). Known from the Amazon (Ref. 598), Machado and Acre River basins (Ref. 97592). Also Ref. 124043. + 
Characidae Tetragonopterus carvalhoi Melo, Benine, Mariguela & Oliveira, 2011 Fr endemic   6.45 cm SL male/unsexed  Type locality of Tetragonopterus carvalhoi, Amapá, Laranjal do Jari, Igarapé Iratapuru, rio Jari, Amazon basin, MZUSP 102268 (holotype, 3.65 cm SL). Found in rio Jari, upstream from the Cachoeira de Santo Antônio, rio Amazonas drainage, Amapá, northern Brazil (Ref. 86682). Also Ref. 87186, 124043. - 
Characidae Tetragonopterus chalceus Spix & Agassiz, 1829 Fr native  Matupiri (Portuguese), Piaba (Portuguese), Piaba do rio (Portuguese), Piaba rapadura (Portuguese) fairly common (chances are about 50%) 12.70 cm TL male/unsexed  Known from the Amazon basin and Rio San Francisco (Ref. 12225). Also Ref. 87186. + 
Characidae Tetragonopterus denticulatus Silva, Melo, Oliveira & Benine, 2013 Fr native   6.79 cm SL male/unsexed  Type locality of Tetragonopterus denticulatus, Goias, Aragarc¸as, Rio Araguaia, Amazon basin. Known from the middle Rio Araguaia, at the border of the states of Goiás and Mato Grosso, central Brazil (Ref. 93280) and extending Rio Tocantins (Ref. 124043). - 
Characidae Tetragonopterus franciscoensis Silva, Melo, Oliveira & Benine, 2016 Fr native  Piaba-rapadura (Portuguese)  9.28 cm SL male/unsexed  Type locality of Tetragonopterus franciscoensis, Minas Gerais, Três Marias, Rio São Francisco. Known in the Rio São Francisco basin, Rio Paraguaçu and Rio Itapicuru, all coastal drainages of northeastern Brazil (Ref. 124043). - 
Characidae Tetragonopterus juruena Silva, Melo, Oliveira & Benine, 2016 Fr native   7.55 cm SL male/unsexed  Type locality of Tetragonopterus juruena, Mato Grosso, Sapezal, Rio Juruena, upper Rio Tapajós. Known from the Rio Juruena and Rio Teles Pires, both major tributaries of the Rio Tapajós, Amazon basin (Ref. 124043). - 
Characidae Tetragonopterus kuluene Silva, Melo, Oliveira & Benine, 2016 Fr native   6.39 cm SL male/unsexed  Type locality of Tetragonopterus kuluene, Mato Grosso, Paranatinga, Rio Culuene, Rio Xingu basin. Known from rio Xingu basin (Amazon basin), its upper portions, such as the Rio Culuene, Rio Suiá-Missu and Rio Curuá and lower portion of the basin, Volta Grande (Ref. 124043). - 
Characidae Tetragonopterus ommatus Silva, Melo, Oliveira & Benine, 2016 Fr native   6.59 cm SL male/unsexed  Type locality of Tetragonopterus ommatus, Pará, Itaituba, Rio Tapajós. Known near the Cachoeira de São Luiz, middle Rio Tapajós, municipality of Itaituba, Pará (Ref. 124043). - 
Characidae Tetragonopterus rarus (Zarske, Géry & Isbrücker, 2004) Fr native   8.54 cm SL male/unsexed  Known from the Rio Jari, and Rio Paru of the Amazon basin, northern Brazil (Ref. 124043). Recorded from the Alto Pará do Oeste, rio Amazonas, affluent to rio Tírios in Pará (Ref. 96868). Also Ref. 87186. - 
Auchenipteridae Tetranematichthys barthemi Peixoto & Wosiacki, 2010 Fr, Br native    17.57 cm SL male/unsexed  Known from the lower Amazon, between the mouth of the rio Negro and the mouth of the rio Trombetas (Ref. 83952). - 
Auchenipteridae Tetranematichthys quadrifilis (Kner, 1858) Fr native  Bagri (Portuguese), Danimaru (Portuguese)   16.00 cm SL male/unsexed    + 
Auchenipteridae Tetranematichthys wallacei Vari & Ferraris, 2006 Fr native    20.60 cm SL male/unsexed  Type locality, Mouth of Igarapé do Ibará, São Pedro, upper Rio Negro, Amazonas, MZUSP 31096 (holotype of Tetranematichthys wallacei, 17.1 cm SL, nuptial male) (Ref. 56964). + 
Batrachoididae Thalassophryne amazonica Steindachner, 1876 Fr native   9.30 cm SL male/unsexed  Type locality, mouth of Rio Negro and at Tabatinga and Xingu, Brazil (Ref. 26282, 30721). + 
Characidae Thayeria boehlkei Weitzman, 1957 Fr native   3.15 cm SL male/unsexed   + 
Characidae Thayeria ifati Géry, 1959 Fr misidentification   3.50 cm SL male/unsexed  Present in the Amazon basin (Ref. 12225). Occurrence in the country not confirmed by F.C.T. Lima and C. Moreira. + 
Characidae Thayeria obliqua Eigenmann, 1908 Fr native  Santa Maria (Portuguese)  7.60 cm SL male/unsexed   + 
Gasteropelecidae Thoracocharax securis (De Filippi, 1853) Fr, Fi native   6.80 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39056). + 
Gasteropelecidae Thoracocharax stellatus (Kner, 1858) Fr native  Papudinho (Portuguese), Machadinha (Portuguese), Papuda (Portuguese), Pataca (Portuguese)   6.70 cm SL male/unsexed  Found in the Acre River basin (Ref. 97592). + 
Characidae Thrissobrycon pectinifer Böhlke, 1953 Fr native   3.02 cm SL male/unsexed   - 
Auchenipteridae Tocantinsia piresi (Miranda Ribeiro, 1920) Fr native  Anojado (Portuguese), Boca de sapato (Portuguese), Capadinho (Portuguese), Pocomão (Portuguese)   51.50 cm TL male/unsexed  Found in the Rio São Manoez and in the upper course of Rio Tocantins near Piexa (Ref. 6868). + 
Serrasalmidae Tometes ancylorhynchus Andrade, Jégu & Giarrizzo, 2016 Fr native   39.50 cm TL male/unsexed  Type locality of Tometes ancylorhynchus. - 
Serrasalmidae Tometes camunani Andrade, Giarrizzo & Jégu, 2013 Fr native   91.08 cm SL male/unsexed  Found in the upper rio Trombetas and its tributaries rio Mapuera, rio Cachorro, and rio Erepecuru draining the Guiana Shield, Pará State (Ref. 93807). - 
Serrasalmidae Tometes makue Jégu, Santos & Belmont-Jégu, 2002 Fr native   37.90 cm SL male/unsexed  Known from the Negro River basin (Ref. 39031). Type-locality of holotype of Tometes makue: 'Brésil: Amazonas: Ile d'Acara, en aval de São Gabriel da Cachoeira, Rio Negro' (Ref. 46931). - 
Serrasalmidae Tometes siderocarajensis Andrade, Machado, Jégu, Farias & Giarrizzo, 2017 Fr, Sp native   35.20 cm SL male/unsexed  Known from the Itacaiúnas River and in its right-bank tributary, the Cateté River (average elevation of localities around 220 m a.s.l.), both located in the Mosaic of Conservation Units of Serra dos Carajás, Tocantins-Araguaia River Basin, State of Pará. Together with Tometes kranponhah and Mylesinus paucisquamatus, this species is locally referred as ‘pacu‒borracha' (literally translated as `rubber pacu'), because of the rubbery texture of its flesh when cooked (Ref. 116762). - 
Serrasalmidae Tometes trilobatus Valenciennes, 1850 Fr native  Pacu (Portuguese)  43.00 cm SL male/unsexed   + 
Poeciliidae Tomeurus gracilis Eigenmann, 1909 Fr native   3.30 cm TL male/unsexed   + 
Auchenipteridae Trachelyopterichthys taeniatus (Kner, 1858) Fr native    15.00 cm TL male/unsexed  Known from the Amazon River (Ref. 37098). + 
Auchenipteridae Trachelyopterus analis (Eigenmann & Eigenmann, 1888) Fr native    Type locality, Lago Arari, Pará (Ref. 46206). - 
Auchenipteridae Trachelyopterus ceratophysus (Kner, 1858) Fr native   25.50 cm TL male/unsexed  Known from Guaporé, Branco, and Negro River basins (Ref. 37098). - 
Auchenipteridae Trachelyopterus coriaceus Valenciennes, 1840 Fr native    18.00 cm TL male/unsexed  Found in Porto do Moz (Ref. 6868). Known from the Amazon River basin (Ref. 37098). + 
Auchenipteridae Trachelyopterus cratensis (Miranda Ribeiro, 1937) Fr native  Cangati (Portuguese)  6.06 cm SL male/unsexed  Found in the Granjeiro River basin, Ceará (Ref. 6868, 37098). - 
Auchenipteridae Trachelyopterus galeatus (Linnaeus, 1766) Fr, Fi native  Jauzinho (Portuguese), Anduiá (Portuguese), Anojado (Portuguese), Anuiá (Portuguese), Anujá (Portuguese), Bagre-mole (Portuguese), Cabeça de ferro (Portuguese), Cachoro do padre (Portuguese), Cachorrinho (Portuguese), Cachorrinho de padre (Portuguese), Cachorro (Portuguese), Cachorro de padre (Portuguese), Cachorro-do-padre (Portuguese), Cangatá (Portuguese), Cangati (Portuguese), Cangatí (Portuguese), Capadinho (Portuguese), Carataí (Portuguese), Chorão (Portuguese), Chorãozinho (Portuguese), Cumbá (Portuguese), Cumbaca (Portuguese), Cumbáca (Portuguese), Mandi (Portuguese), Mandi cumbá (Portuguese), Mandí cumbá (Portuguese), Mandí sapo (Portuguese), Mandizinho (Portuguese), Morrudo (Portuguese), Pacamão (Portuguese), Pacu (Portuguese), Peixe cachorro (Portuguese), Pocomão (Portuguese), Ronca ronca (Portuguese)   30.00 cm TL male/unsexed ;23.00 cm TL female 11.3 TL Recorded from the Caracu and Sao Pedro streams, both tributaries of the Paraná river (Ref. 26076). Found in the Uruguay River (Ref. 79585). Also Ref. 37098, 81048. + 
Auchenipteridae Trachelyopterus lacustris (Lütken, 1874) Fr native    Known from Das Velhas River and Lagoa Santa basins (Ref. 37098). - 
Auchenipteridae Trachelyopterus leopardinus (Borodin, 1927) Fr native  Cangati (Portuguese)   18.00 cm TL male/unsexed  Known from the Rio São Francisco in Minas Gerais (Ref. 6868). Recorded as threatened in the state of Minas Gerais (Ref. 26603). - 
Auchenipteridae Trachelyopterus lucenai Bertoletti, Pezzi da Silva & Pereira, 1995 Fr native  Southern driftwood catfish (English), Penharol (Portuguese), Porrudo (Portuguese)   16.50 cm SL male/unsexed  Known from Jacuí River basin in Rio Grande do Sul (Ref. 37098). + 
Auchenipteridae Trachelyopterus porosus (Eigenmann & Eigenmann, 1888) Fr native     - 
Auchenipteridae Trachelyopterus striatulus (Steindachner, 1877) Fr native  Jauzinho (Portuguese), Cangati (Portuguese), Cumbaca (Portuguese), Peixe cachorro (Portuguese)   27.70 cm TL male/unsexed  Found in the Rio Paraiba, Campos and Rio Doce, Linhares (Ref. 6868). + 
Auchenipteridae Trachelyopterus teaguei (Devincenzi, 1942) Fr native  Bagre-mole (Portuguese), Cangati (Portuguese)  19.70 cm TL male/unsexed  Found in the Uruguay River (Ref. 79585). - 
Auchenipteridae Trachycorystes menezesi Britski & Akama, 2011 Fr native   19.92 cm SL male/unsexed  Found in rio Aripuanã (Madeira drainage) and its tributaries above the falls of Dardanelos and Andorinhas in Mato Grosso State (Ref. 87314). - 
Auchenipteridae Trachycorystes trachycorystes (Valenciennes, 1840) Fr native    35.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 37098). + 
Doradidae Trachydoras brevis (Kner, 1853) Fr native    13.90 cm TL male/unsexed  Found in Barro do Rio Negro (Ref. 6868). - 
Doradidae Trachydoras gepharti Sabaj & Arce H., 2017 Fr native   7.12 cm SL male/unsexed   - 
Doradidae Trachydoras microstomus (Eigenmann, 1912) Fr native    5.90 cm SL male/unsexed    - 
Doradidae Trachydoras nattereri (Steindachner, 1881) Fr native   12.40 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Doradidae Trachydoras paraguayensis (Eigenmann & Ward, 1907) Fr native  Rique-rique (Portuguese), Armadinho (Portuguese)   19.20 cm SL male/unsexed 6.2 TL Known from the Paraná River (Ref. 37054). - 
Doradidae Trachydoras steindachneri (Perugia, 1897) Fr native  Corno (Portuguese), Mandi (Portuguese), Maniquim (Portuguese)   16.00 cm SL male/unsexed  Known from the Amazon River (Ref. 37054). + 
Trichomycteridae Trichogenes claviger de Pinna, Helmer, Britski & Nunes, 2010 Fr native    5.08 cm SL male/unsexed  Type locality, State of Espírito Santo, Municipality of Castelo, córrego Picada Comprida (tributary, in sequence, to ribeirão Braço Sul, rio Caxixe and rio Castelo), rio Itapemirim drainage, MBML 3289 (holotype of Trichogenes claviger, 5.08 cm SL). Known only from the type locality, an upland tributary of the headwaters of the rio Itapemirim drainage in southeastern Brazil (Ref. 85858). + 
Trichomycteridae Trichogenes longipinnis Britski & Ortega, 1983 Fr native  Cambeva-da-cachoeira (Portuguese), Long-finned cambeva (English)   14.00 cm SL male/unsexed ;10.60 cm SL female  Known from the coastal streams between Rio de Janeiro and São Paulo States, southeastern Brazil (23º17-21’S, 44º44-47’W, 149-656 m altitude). Due to restricted distribution, specialised habitat, and differentiated populations, the vulnerable (VU B1+2bc) status in the IUCN List is proposed (Ref. 50917). Also Ref. 6868, 39970. + 
Trichomycteridae Trichomycterus albinotatus Costa, 1992 Fr native   4.63 cm male/unsexed  Found in Preto River, tributary of Paraíba do Sul River (Ref. 39970). + 
Trichomycteridae Trichomycterus alternatus (Eigenmann, 1917) Fr native    8.10 cm male/unsexed  Found in coastal river basins in Rio de Janeiro and Espírito Santo States (Ref. 39970). Type locality: Rio Doce, Brazil (Ref. 26282, 6868). - 
Trichomycteridae Trichomycterus argos Lezama, Triques & Santos, 2012 Fr native   11.68 cm SL male/unsexed  Known from the Rio Doce basin, situated in the Serra do Brigadeiro (part of the Serra da Mantiqueira) range, southeastern Brazil (Ref. 90333). - 
Trichomycteridae Trichomycterus auroguttatus Costa, 1992 Fr native   6.06 cm male/unsexed  Found in Marimbondo River, tributary of the Preto River, Paraíba do Sul River basin (Ref. 39970). + 
Trichomycteridae Trichomycterus bahianus Costa, 1992 Fr native   8.86 cm male/unsexed  Found in tributary stream of Ribeirão Caveira, Una River basin in Bahia, (Ref. 39970). - 
Trichomycteridae Trichomycterus balios Ferrer & Malabarba, 2013 Fr native   9.24 cm SL male/unsexed  Known from the upper portions of the rio das Antas and rio Caí tributaries to the laguna dos Patos system and in the headwaters of the rio Mampituba (Ref. 93814). - 
Trichomycteridae Trichomycterus brachykechenos Ferrer & Malabarba, 2013 Fr native   7.09 cm SL male/unsexed  Known only from the rio do Sinos in the laguna dos Patos system (Ref. 93814). - 
Trichomycteridae Trichomycterus brasiliensis Lütken, 1874 Fr native  Acangapeva (Portuguese), Bagre branco (Portuguese), Bagre cambeja (Portuguese), Bagre mole (Portuguese), Bagrinho (Portuguese), Bagrinho da serra (Portuguese), Cambeba (Portuguese), Cambeja (Portuguese), Cambeva (Portuguese), Peixe gato (Portuguese)   13.54 cm SL male/unsexed  Found in the upper São Francisco River in Minas Gerais and in smaller adjoining basins in southeastern Brazi (Ref. 39970). Type locality: Rio das Velhas, Minas Gerais, Brazil (Ref. 26282). Also Ref. 6868. + 
Trichomycteridae Trichomycterus brunoi Barbosa & Costa, 2010 Fr native       - 
Trichomycteridae Trichomycterus caipora Lima, Lazzarotto & Costa, 2008 Fr native   11.62 cm SL male/unsexed   - 
Trichomycteridae Trichomycterus candidus (Miranda Ribeiro, 1949) Fr native   7.50 cm male/unsexed  Known from the Grande River basin in Minas Gerais (Ref. 39970). Type locality: Rio Espirito Santo, trib. of the Rio Claro, east of Sapucaí, Estado de Minas Gerais, Brazil (Ref. 26282, 6868). - 
Trichomycteridae Trichomycterus castroi de Pinna, 1992 Fr native  Cambeva (Portuguese)   14.83 cm male/unsexed  Type locality: Branch of Rio Iguaçu, near the point crossed by Curitiba-Paranaguá Road., State of Paraná. Also Ref. 39970. - 
Trichomycteridae Trichomycterus caudofasciatus Alencar & Costa, 2004 Fr native    5.29 cm SL male/unsexed  Known from the upper Rio Itabapoana basin, Serra do Caparaó in southeastern Brazil (Ref. 53352). - 
Trichomycteridae Trichomycterus claudiae Barbosa & Costa, 2010 Fr native     - 
Trichomycteridae Trichomycterus concolor Costa, 1992 Fr native  Bagrinho (Portuguese)  6.43 cm male/unsexed  Known from the upper São Francisco River basin (Ref. 39970). - 
Trichomycteridae Trichomycterus crassicaudatus Wosiacki & de Pinna, 2008 Fr native    13.45 cm SL male/unsexed  Known from the Rio Iguaçu basin in southern Brazil (Ref. 75785). - 
Trichomycteridae Trichomycterus dali Rizzato, Costa, Trajano & Bichuette, 2011 Fr native   7.89 cm SL male/unsexed   - 
Trichomycteridae Trichomycterus davisi (Haseman, 1911) Fr native    20.80 cm SL male/unsexed  Known from Iguaçu and Ribeira de Iguape River basins (Ref. 39970). Type locality: Serrinha Paraná, Rio Iguaçu system, Brazil (Ref. 26282). Also Ref. 6868. - 
Trichomycteridae Trichomycterus diabolus Bockmann, Casatti & de Pinna, 2004 Fr native   22.50 cm TL male/unsexed  Found only in Corrego São Carlos and Corrego Sete de Setembro, both small tributaries of the Rio Paranapanema (upper Rio Parana region) in the Morro do Diabo State Park, municipio de Teodoro Sampaio, São Paulo (Ref. 55400). - 
Trichomycteridae Trichomycterus diatropoporos Ferrer & Malabarba, 2013 Fr native   6.83 cm SL male/unsexed  Restricted to the rio da Prata and rio Turvo basins, tributaries of rio das Antas, in the laguna dos Patos system (Ref. 93814). - 
Trichomycteridae Trichomycterus fuliginosus Barbosa & Costa, 2010 Fr native     - 
Trichomycteridae Trichomycterus gabrieli (Myers, 1926) Fr native   5.00 cm male/unsexed  Known from the upper Negro River basin (Ref. 39970). Type locality: Rock pools below rapids of Sao Gabriel, Rio Negro, Amazon system, Brazil (Ref. 26282). Also Ref. 6868. - 
Trichomycteridae Trichomycterus gasparinii Barbosa, 2013 Fr native   8.45 cm SL male/unsexed  Found in the creek crossing the road between the towns of Fundão and Santa Teresa, close to Goiapabaçu Park, a tributary of the rio Reis Magos basin in southeastern Brazil (Ref. 94725). - 
Trichomycteridae Trichomycterus giganteus Lima & Costa, 2004 Fr native   20.40 cm SL male/unsexed  Known from the upper Rio Guandu basin in Serra do Mendanha, southeastern Brazil (Ref. 54465). + 
Trichomycteridae Trichomycterus goeldii Boulenger, 1896 Fr native   9.90 cm TL male/unsexed  Found in mountain ranges of coastal basins of Rio de Janeiro (Ref. 39970). Type locality: Vicinity of Rio (about 790 m altitude) (Ref. 6868). - 
Trichomycteridae Trichomycterus guaraquessaba Wosiacki, 2005 Fr native   9.15 cm SL male/unsexed  Knonw from rio Bracinho in Municipio De Guaraqueçaba, Paraná (Ref. 56678). - 
Trichomycteridae Trichomycterus igobi Wosiacki & de Pinna, 2008 Fr native    9.01 cm SL male/unsexed  Known from the lower rio rio Jordão, close to its mouth on rio Iguaçu, rio Paraná drainage in southern Brazil (Ref. 75005). - 
Trichomycteridae Trichomycterus iheringi (Eigenmann, 1917) Fr native   16.10 cm male/unsexed  Known from the Ribeira do Iguape River basin (Ref. 39970). Type locality: Sao Paulo, Brazil (Ref. 26282, 6868). + 
Trichomycteridae Trichomycterus immaculatus (Eigenmann & Eigenmann, 1889) Fr native    9.30 cm male/unsexed  Known from the Paraíbuna River, Paraíba do Sul River basin (Ref. 39970). Type locality: Juiz de For a, R. Parahybuna; Sao Matheos; Juiz de For a; Goiás, Brazil (Ref. 26282). Also Ref. 6868. + 
Trichomycteridae Trichomycterus itacambirussu Triques & Vono, 2004 Fr native   7.35 cm SL male/unsexed  Known from from Minas Gerais, Rio Jequitinhonha basin, drainage of rio Itacambirucu. - 
Trichomycteridae Trichomycterus itacarambiensis Trajano & de Pinna, 1996 Fr endemic  Bagrinho (Portuguese), Cambeva (Portuguese)   8.30 cm SL male/unsexed 6.7 SL Type locality: Creek inside Olhos d'Agua cave, Município de Itacarambi, Minas Gerais, Brazil, 15°06'06"S, 44°09'30"W. Also Ref. 39970. + 
Trichomycteridae Trichomycterus itatiayae Miranda Ribeiro, 1906 Fr native    19.70 cm SL male/unsexed  Known from rivers in Itatiaia mountains, upper reaches of Paraiba do Sul River basin (Ref. 39970). Type locality: Itatiaia, Brazil (Ref. 26282, 6868). + 
Trichomycteridae Trichomycterus jacupiranga Wosiacki & Oyakawa, 2005 Fr native    Known from Rio Ribeira de Iguape basin in southeastern Brazi (Ref. 56907). - 
Trichomycteridae Trichomycterus jequitinhonhae Triques & Vono, 2004 Fr native   8.40 cm SL male/unsexed  Known from from Minas Gerais, County of Coronel Murta, Rio Jequitinhonha basin. - 
Trichomycteridae Trichomycterus landinga Triques & Vono, 2004 Fr native   4.31 cm SL male/unsexed  Known from Corrego Moquem, Rio Jequitinhonha basin in County of Coronel Murta, Minas Gerais (Ref. 52473). - 
Trichomycteridae Trichomycterus longibarbatus Costa, 1992 Fr native   5.84 cm male/unsexed  Occurs near near Santa Tereza, Espírito Santo (Ref. 39970). - 
Trichomycteridae Trichomycterus macrophthalmus Barbosa & Costa, 2012 Fr native   6.00 cm SL male/unsexed  Known only from the type locality, a small stream tributary to upper Piraí river, Araras hill, upper Paraíba do Sul river basin in southeastern Brazil (Ref. 89884). - 
Trichomycteridae Trichomycterus macrotrichopterus Barbosa & Costa, 2010 Fr native     - 
Trichomycteridae Trichomycterus maculosus Barbosa & Costa, 2010 Fr native   7.69 cm SL male/unsexed  Known from the upper rio do Peixe drainage, serra da Mantiqueira, upper rio Paraíba do Sul basin in southeastern Brazil (Ref. 86272). - 
Trichomycteridae Trichomycterus maracaya Bockmann & Sazima, 2004 Fr native  Margay pencil catfish (English)   5.10 cm SL male/unsexed  Type locality, unnamed streamlet of the Rio Pardo drainage, upper Rio Paraná, southeastern Brazil (Ref. 51380). + 
Trichomycteridae Trichomycterus mariamole Barbosa & Costa, 2010 Fr native     - 
Trichomycteridae Trichomycterus mboycy Wosiacki & Garavello, 2004 Fr native    12.57 cm SL male/unsexed  Known from rio Iguaçu (rio Paraná Basin), State of Paraná (Ref. 52482). - 
Trichomycteridae Trichomycterus mimonha Costa, 1992 Fr native   7.80 cm male/unsexed  Known from Benfica River, Paraíba do Sul River basin (Ref. 39970). - 
Trichomycteridae Trichomycterus mimosensis Barbosa, 2013 Fr native   5.43 cm SL male/unsexed  Known from the upper rio Alto Pratinha drainage, tributary of rio Muqui do Sul, tributary of the Itabapoana river basin in southeastern Brazil (Ref. 94725). - 
Trichomycteridae Trichomycterus mirissumba Costa, 1992 Fr native   5.96 cm male/unsexed  Known from Preto River, Paraíba do Sul River basin (Ref. 39970). + 
Trichomycteridae Trichomycterus naipi Wosiacki & Garavello, 2004 Fr native   12.15 cm SL male/unsexed  Known from from Rio Iguaçu basin, State of Paraná. - 
Trichomycteridae Trichomycterus nigricans Valenciennes, 1832 Fr native   8.90 cm male/unsexed  Found in coastal drainages in Santa Catarina (Ref. 39970). Type locality: Rio de Janeiro (Ref. 26282). Also Ref. 6868. + 
Trichomycteridae Trichomycterus nigroauratus Barbosa & Costa, 2008 Fr native   7.32 cm SL male/unsexed   - 
Trichomycteridae Trichomycterus novalimensis Barbosa & Costa, 2010 Fr native     - 
Trichomycteridae Trichomycterus oroyae (Eigenmann & Eigenmann, 1889) Fr native    Type locality, Rio Oroya, Pochachara (Ref. 87661). - 
Trichomycteridae Trichomycterus pantherinus Alencar & Costa, 2004 Fr native   6.99 cm SL male/unsexed  Known only from the type locality, Rio da Prata, Rio Santa Maria da Vitória basin, Serra dos Polacos in southeastern Brazil (Ref. 53352). - 
Trichomycteridae Trichomycterus paolence (Eigenmann, 1917) Fr native  Cambeva (Portuguese)   6.80 cm male/unsexed  Known from the Paraná River basin (Ref. 39970). Type locality: Rio Tieté, Sao Paulo, Brazil (Ref. 26282, 6868). + 
Trichomycteridae Trichomycterus papilliferus Wosiacki & Garavello, 2004 Fr native    12.72 cm SL male/unsexed  Known from Rio Jordão, tributary of rio Iguaçu, rio Paraná basin, State of Paraná (Ref. 52482). - 
Trichomycteridae Trichomycterus paquequerense (Miranda Ribeiro, 1943) Fr native   6.80 cm SL male/unsexed  Known from the Paquequer River, Paraíba do Sul River basin (Ref. 39970). Type locality: Rio Paquequer Grande, Rio de Janeiro (Ref. 26282, 6868). - 
Trichomycteridae Trichomycterus pauciradiatus Alencar & Costa, 2006 Fr native    5.20 cm SL male/unsexed  Found only in córrego Debaixo da Serra, tributary of córrego Agua Limpa, upper rio Paraná basin in southeastern Brazil (Ref. 57604). - 
Trichomycteridae Trichomycterus payaya Sarmento-Soares, Zanata & Martins-Pinheiro, 2011 Fr native   3.74 cm SL male/unsexed  Recorded from the two tributaries of the rio Itapicurumirim, in the headwaters of the rio Itapicuru basin, northern Bahia State (Ref. 87309). - 
Trichomycteridae Trichomycterus perkos Datovo, Carvalho & Ferrer, 2012 Fr native    Known from the Tibaji River basin, a tributary of the Paranapanema River; Ijuí and Passo Fundo drainages of the Uruguai River system (Ref. 90267). - 
Trichomycteridae Trichomycterus pirabitira Barbosa & Azevedo-Santos, 2012 Fr native   7.72 cm SL male/unsexed  Found in two streams, tributaries of the upper rio Grande, rio Paraná basin in southeastern Brazil: rio Cuiabá, and a small river without name (Ref. 92859). + 
Trichomycteridae Trichomycterus piratymbara Katz, Barbosa & Costa, 2013 Fr native    Type locality of Trichomycterus piratymbara from João Pinheiro stream, on road to Cristais, Estado de Minas Gerais, Brazil, UFRJ 8602 (Ref. 93165). - 
Trichomycteridae Trichomycterus plumbeus Wosiacki & Garavello, 2004 Fr native    8.24 cm SL male/unsexed  Found in Rio Jordão near its mouth, tributary of rio Iguaçu (rio Paraná Basin), Jordão reservoir, município Foz do Jordão, State of Paraná. - 
Trichomycteridae Trichomycterus poikilos Ferrer & Malabarba, 2013 Fr native   9.25 cm SL male/unsexed  Known from rio Jacuí, rio Pardo and rio Taquari-Antas basins in the laguna dos Patos system (Ref. 93814). - 
Trichomycteridae Trichomycterus potschi Barbosa & Costa, 2003 Fr native   8.05 cm SL male/unsexed  Known only from the type locality, in coastal basins between Mangaratiba and Itaguaí in Rio de Janeiro, southeastern Brazil (Ref. 52913). - 
Trichomycteridae Trichomycterus pradensis Sarmento-Soares, Martins-Pinheiro, Aranda & Chamon, 2005 Fr native    11.21 cm SL male/unsexed  Knonw from the lower course of rio Peruípe; upper and middle rio Jucuruçu and upper rio Itanhém, in southeastern Bahia and in northeastern Minas Gerais State (Ref. 56791). - 
Trichomycteridae Trichomycterus punctatissimus Castelnau, 1855 Fr native   28.00 cm TL male/unsexed  Known from the Araguaia River basin (Ref. 39970). Type locality: Rio Araguaia, Brazil (Ref. 26282). Also Ref. 6868. - 
Trichomycteridae Trichomycterus puriventris Barbosa & Costa, 2012 Fr native   8.01 cm SL male/unsexed  Known from the tributaries of the upper rio Santíssimo, rio Grande drainage, rio Paraíba do Sul basin, Serra do Barracão in southeastern Brazil (Ref. 91059). - 
Trichomycteridae Trichomycterus reinhardti (Eigenmann, 1917) Fr native  Cambeva (Portuguese), Peixe gato (Portuguese)  6.50 cm male/unsexed  Known from the upper São Francisco River basin (Ref. 39970). Type locality: Rio Itabira at Burmier, trib. Of Rio das Velhas, Brazil (Ref. 26282). Also Ref. 6868. - 
Trichomycteridae Trichomycterus rivulatus Valenciennes, 1846 Fr native  Bagre (Portuguese), Boga (Portuguese), Maurí (Portuguese)  37.40 cm TL male/unsexed   + 
Trichomycteridae Trichomycterus rubbioli Bichuette & Rizzato, 2012 Fr native   6.41 cm SL male/unsexed  Found in subterranean waters in at least two caves of the same cave system in the Serra do Ramalho karst area, middle São Francisco River basin in Bahia State: Lapa dos Peixes and Gruna da Água Clara (Ref. 91769). - 
Trichomycteridae Trichomycterus rubiginosus Barbosa & Costa, 2010 Fr native     - 
Trichomycteridae Trichomycterus santaeritae (Eigenmann, 1918) Fr native   6.60 cm male/unsexed  Found in Preto River, Paraíba do Sul River basin (Ref. 39970). Type locality: Rio Preto at Santa Rita, Brazil (Ref. 6868, 26282). - 
Trichomycteridae Trichomycterus septemradiatus Katz, Barbosa & Costa, 2013 Fr native    Type locality of Trichomycterus septemradiatus from the stream tributary of Cuiabá river, tributary of Grande river, Paraná river basin, Estado de Minas Gerais, Brazil, UFRJ 8576 (Ref. 93165). - 
Trichomycteridae Trichomycterus stawiarski (Miranda Ribeiro, 1968) Fr native   8.50 cm male/unsexed  Known from the Iguaçu River basin (Ref. 39970). - 
Trichomycteridae Trichomycterus taroba Wosiacki & Garavello, 2004 Fr native   5.87 cm SL male/unsexed  Known from the rio Jordão (tributary of rio Iguaçu), Rio Paraná basin in State of Paraná (Ref. 52482). - 
Trichomycteridae Trichomycterus tete Barbosa & Costa, 2011 Fr native   6.13 cm SL male/unsexed  Found in Cachoeira do Giló, and córrego Morceguinho, tributaries of rio Brumado, upper rio de Contas drainage, serra do Espinhaço, northeastern Brazil (Ref. 88926). - 
Trichomycteridae Trichomycterus trefauti Wosiacki, 2004 Fr endemic     - 
Trichomycteridae Trichomycterus triguttatus (Eigenmann, 1918) Fr native   3.60 cm male/unsexed  Found in São Paulo (Ref. 39970). Type locality: Jacarei, Rio Paraiba, Brazil (Ref. 26282, 6868). - 
Trichomycteridae Trichomycterus tropeiro Ferrer & Malabarba, 2011 Fr native    Found in the headwaters of the rio das Antas, laguna dos Patos system in southern Brazil (Ref. 87104). - 
Trichomycteridae Trichomycterus tupinamba Wosiacki & Oyakawa, 2005 Fr native    Known from rio Ribeira de Iguape basin in southeastern Brazil (Ref. 56907). - 
Trichomycteridae Trichomycterus variegatus Costa, 1992 Fr native  Bagrinho (Portuguese)  4.04 cm male/unsexed  Known from the upper São Francisco River basin (Ref. 39970). - 
Trichomycteridae Trichomycterus vermiculatus (Eigenmann, 1917) Fr native   13.10 cm male/unsexed  Known from Paraiba do Sul River in Minas Gerais (Ref. 39970). Also Ref. 6868. - 
Trichomycteridae Trichomycterus zonatus (Eigenmann, 1918) Fr native   6.20 cm male/unsexed  Found in coastal rivers between Santa Catarina and São Paulo (Ref. 39970). Type locality: Agua Quente, Cubatao, 7 mi. west of Santos, Sao Paulo, Brazil (Ref. 26282). Also Ref. 6868, 55400. - 
Trichomycteridae Tridens melanops Eigenmann & Eigenmann, 1889 Fr native   2.70 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39970). Type locality: Ica, Brazil (Ref. 26282, 6868). - 
Trichomycteridae Tridensimilis brevis (Eigenmann & Eigenmann, 1889) Fr native   3.00 cm TL male/unsexed  Known from the Amazon River basin (Ref. 39970). Type locality: Tabatinga, Amazonas (Ref. 6868, 26282). Also Ref. 6868. + 
Trichomycteridae Tridentopsis tocantinsi La Monte, 1939 Fr native   2.30 cm SL male/unsexed  Known from the Tocantins River basin (Ref. 39970). Type locality: Río Tocantins, northern Brazil (Ref. 26282, 6868). - 
Rivulidae Trigonectes balzanii (Perugia, 1891) Fr native   16.00 cm TL male/unsexed  Known from the Paraguay River basin (Ref. 36579). + 
Rivulidae Trigonectes macrophthalmus Costa, 1990 Fr native   8.00 cm TL male/unsexed  Known from the Guaporé River basin (Ref. 36579). - 
Rivulidae Trigonectes rubromarginatus Costa, 1990 Fr endemic   12.00 cm TL male/unsexed  Known from the Araguaia River basin (Ref. 36579). Also Ref. 27139. + 
Rivulidae Trigonectes strigabundus Myers, 1925 Fr endemic   12.00 cm TL male/unsexed  Known from the Tocantins River basin (Ref. 36579). Also Ref. 27139. - 
Triportheidae Triportheus albus Cope, 1872 Fr native  Sardinha (Portuguese), Sardinha colim (Portuguese), Sardinha comum (Portuguese), Sardinha facão (Portuguese), Sardinha gata (Portuguese)   25.70 cm TL male/unsexed  Found in the Tocantins-Araguaia basin (Ref. 38376). + 
Triportheidae Triportheus angulatus (Spix & Agassiz, 1829) Fr, Fi, B native  Sardinha (Portuguese), Sardinha chata (Portuguese), Sardinha curta (Portuguese), Sardinha moça (Portuguese), Sardinha papo largo (Portuguese), Sardinha papuda (Portuguese) common (usually seen) 23.80 cm SL male/unsexed 11.5 TL Recorded from Machado (Ref. 97589) and Acre River basins (Ref. 97592). Found in fish markets of Santarém (Ref. 12202). Also Ref. 10615. + 
Triportheidae Triportheus auritus (Valenciennes, 1850) Fr native  Sardinha (Portuguese)   26.50 cm SL male/unsexed  Type locality, Amazon R. (Ref. 46206). + 
Triportheidae Triportheus brachipomus (Valenciennes, 1850) Fr native   21.90 cm SL male/unsexed   + 
Triportheidae Triportheus culter (Cope, 1872) Fr native    24.50 cm SL male/unsexed  Found in the Amazon River (Ref. 38376). + 
Triportheidae Triportheus curtus (Garman, 1890) Fr native    10.68 cm SL male/unsexed  Found in the Amazon River (Ref. 38376). - 
Triportheidae Triportheus elongatus (Günther, 1864) Fr, Fi native  Sardinha (Portuguese), Sardinha colim (Portuguese), Sardinha comprida (Portuguese), Sardinha facão (Portuguese), Sardinha gata (Portuguese)   24.20 cm SL male/unsexed    + 
Triportheidae Triportheus guentheri (Garman, 1890) Fr native  Piaba facão (Portuguese), Sardinha (Portuguese)  13.40 cm SL male/unsexed   + 
Triportheidae Triportheus nematurus (Kner, 1858) Fr native  Sardinha (Portuguese)   18.30 cm SL male/unsexed    + 
Triportheidae Triportheus pantanensis Malabarba, 2004 Fr native   15.80 cm SL male/unsexed  Known from rio Paraguay (Ref. 54769). - 
Triportheidae Triportheus paranensis (Günther, 1874) Fr native  Sardinha (Portuguese)  19.00 cm SL male/unsexed   + 
Triportheidae Triportheus pictus (Garman, 1890) Fr native  Sardinha (Portuguese)  10.74 cm SL male/unsexed  Found in the Amazon River (Ref. 38376). - 
Triportheidae Triportheus rotundatus (Jardine, 1841) Fr native  Sardinha (Portuguese)   26.80 cm TL male/unsexed  Found in the Acre River basin (Ref. 97592). + 
Triportheidae Triportheus signatus (Garman, 1890) Fr, Fi native  Sardela (Portuguese), Sardinha (Portuguese) scarce (very unlikely) 19.50 cm TL male/unsexed  Found in Piracicaba river (Ref. 50076). Also Ref. 31923. + 
Triportheidae Triportheus trifurcatus (Castelnau, 1855) Fr native    20.00 cm SL male/unsexed ;21.80 cm SL female 11 SL Found in the Tocantins-Araguaia River basin (Ref. 38376). + 
Characidae Tucanoichthys tucano Géry & Römer, 1997 Fr native   1.66 cm SL male/unsexed  Also Ref. 38376. + 
Auchenipteridae Tympanopleura atronasus (Eigenmann & Eigenmann, 1888) Fr native    14.90 cm SL male/unsexed    + 
Auchenipteridae Tympanopleura brevis (Steindachner, 1881) Fr native  Mandubé (Portuguese), Mandubi (Portuguese)   16.00 cm SL male/unsexed  Known from the Amazon River (Ref. 37098). - 
Auchenipteridae Tympanopleura cryptica Walsh, Ribeiro & Rapp Py-Daniel, 2015 Fr native   8.49 cm SL male/unsexed  Known from the middle and upper Amazon River basin, State of Amazonas (Ref. 103256). - 
Auchenipteridae Tympanopleura longipinna Walsh, Ribeiro & Rapp Py-Daniel, 2015 Fr native   8.13 cm SL male/unsexed  Known throughout the upper and middle Amazon River basin (Ref. 103256). - 
Auchenipteridae Tympanopleura piperata Eigenmann, 1912 Fr native    9.50 cm SL male/unsexed  Known from the upper Negro rivers near confluence of Branco River (Ref. 37098). - 
Auchenipteridae Tympanopleura rondoni (Miranda Ribeiro, 1914) Fr native   17.40 cm SL male/unsexed  Known from the central Amazon River basin, including the rio Madeira (Ref. 103256). - 
Trichomycteridae Typhlobelus auriculatus de Pinna & Zuanon, 2013 Fr native   2.98 cm SL male/unsexed  Known from the lower rio Xingu (Ref. 94274). - 
Trichomycteridae Typhlobelus macromycterus Costa & Bockmann, 1994 Fr native   2.19 cm SL male/unsexed  Known from Tocantins River near Tucuruí, Pará (Ref. 39970). - 
Trichomycteridae Typhlobelus ternetzi Myers, 1944 Fr native   3.35 cm SL male/unsexed  Known from the upper Negro River basin (Ref. 39970). Type locality: Rock pools belowe Sao Gabriel rapids, Rio Negro, Brazil (Ref. 26282, 6868). - 
Characidae Tyttobrycon marajoara Marinho, Bastos & Menezes, 2013 Fr native   2.11 cm SL male/unsexed  Found in two small streams located on the east portion of Marajó Island, Pará State (Ref. 94718). - 
Characidae Tyttobrycon xeruini Géry, 1973 Fr native   2.26 cm SL male/unsexed  Recorded from the Rio Negro. - 
Characidae Tyttocharax cochui (Ladiges, 1950) Fr native   2.14 cm SL male/unsexed  Known from the Amazon River basin (Ref. 38597). + 
Characidae Tyttocharax madeirae Fowler, 1913 Fr native    2.09 cm SL male/unsexed  Known from the tributaries of lower and middle Amazon River basin (Ref. 38597). Found in the Machado (Ref. 97589) and Acre River basins (Ref. 97592). - 
Cichlidae Uaru amphiacanthoides Heckel, 1840 Fr, Fi native  Bararuá (Portuguese), Acará bararuá (Portuguese), Acará-fuso (Portuguese), Baru (Portuguese), Uaru (Portuguese), Uaru urá (Portuguese)  25.00 cm SL male/unsexed  Known from Amazon River basin, along the Amazon-Solimões River drainage from the Japurá River to the Tapajós River, and in the middle and lower Negro River basin (Ref. 36377). Also Ref. 12251. + 
Serrasalmidae Utiaritichthys esguiceroi Pereira & Castro, 2014 Fr native   26.00 cm SL male/unsexed  Known from the rio Juruena, Tapajós drainage, upriver of Salto de Utiariti (waterfall), município de Sapezal, Mato Grosso State (Ref. 96883). - 
Serrasalmidae Utiaritichthys longidorsalis Jégu, Tito de Morais & Santos, 1992 Fr native   20.30 cm SL male/unsexed  Known from the Madeira River basin (Ref. 39031). Type locality: Rio Aripuana, 3 km from above the Dardanellos Fall, Madeira basin, 60°40'W, 9°10'S, Brazil (Ref. 39031). + 
Serrasalmidae Utiaritichthys sennaebragai Miranda Ribeiro, 1937 Fr native  Pacu (Portuguese), Curupete (Portuguese), Curupetê (Portuguese), Pacu bandeira (Portuguese), Pacu da pedra (Portuguese), Pacu dente seco (Portuguese), Pacu lombo de foia (Portuguese)  32.20 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39031). Recorded from Tapajos, Tocantins and Araguaia rivers (Ref. 598). Type locality: Amont de Salto Utiarity, 13°S, 58°15'W, Affluent of Rio Papagaio, Mato Grosso, ne. Brazil (Ref. 26282). - 
Trichomycteridae Vandellia cirrhosa Valenciennes, 1846 Fr native  Candiru (Portuguese), Candiru de cavalo (Portuguese) fairly common (chances are about 50%) 17.00 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39970). + 
Trichomycteridae Vandellia sanguinea Eigenmann, 1917 Fr native  Candiru (Portuguese)   8.40 cm SL male/unsexed  Known from the Amazon River basin (Ref. 39970). Type locality: San Antonio de Rio Madeira, Brazil (Ref. 26282, 6868). + 
Doradidae Wertheimeria maculata Steindachner, 1877 Fr native   30.00 cm SL male/unsexed  Found in the Rio Jequitinhonha (Ref. 6868). - 
Balistidae Xanthichthys ringens (Linnaeus, 1758) Fr, M questionable  Cangulo rei (Portuguese), Cangulo-mirim (Portuguese), Gatilho-preto (Portuguese) scarce (very unlikely) 25.00 cm TL male/unsexed  Reported from 7251, 13442, 84211; outside distributional range (Ref. 97685); needs further confirmation. + 
Characidae Xenurobrycon coracoralinae Moreira, 2005 Fr native   1.52 cm SL male/unsexed  Known from the rio Araguaia basin (Ref. 56894). - 
Characidae Xenurobrycon macropus Myers & Miranda Ribeiro, 1945 Fr native   2.00 cm SL male/unsexed  Known from the Paraguay River basin (Ref. 38597). - 
Characidae Xenurobrycon polyancistrus Weitzman, 1987 Fr native    1.44 cm SL male/unsexed   - 
Characidae Xenurobrycon pteropus Weitzman & Fink, 1985 Fr native   1.46 cm SL male/unsexed  Found in the vicinity of Fonte Boa, Amazonas (Ref. 38597). Museum: An igarapé in Fonte Boa, Amazonas, MZUSP 12412 (holotype of X. pteropus, 1.35 cm SL, male) (Ref. 27925). - 
Characidae Xenurobrycon varii Mendonça, Peixoto, Dutra & Netto-Ferreira, 2016 Fr native   1.43 cm SL male/unsexed  Known from the tributary streams of rio Tapajós and rio Jamanxim. This species could be classified as Least Concern (LC) due to the absence of relevant threats. However, at least five major hydroelectric power plants are expected to be built in the occurrence area of the species by the Brazilian government. These may pose highly plausible impacts to the population of Xenurobrycon varii (Ref. 109914). - 
Rivulidae Xenurolebias cricarensis Costa, 2014 Fr native   3.51 cm SL male/unsexed ;2.81 cm SL female  Found only in a temporary swamp close to the town of Conceiçao da Barra, São Mateus river basin in northern Espírito Santo state, eastern Brazil (Ref. 96072). - 
Rivulidae Xenurolebias izecksohni (Da Cruz, 1983) Fr endemic    6.00 cm TL male/unsexed  Found only in the Barra Seca river basin in northern Estado do Espírito Santo, eastern Brazil (Ref. 96072). Also Ref. 107038. - 
Rivulidae Xenurolebias myersi (Carvalho, 1971) Fr native    6.00 cm TL male/unsexed  Known from seasonal pools between the Doce creek (18°20'52"S 39°40'12" W) and the type locality, the Velha Antônia creek (18°25'34"S 39°43'00"W), including the Itaúnas river floodplains in northern Espírito Santo state, eastern Brazil. The Velha Antônia creek is located in the urban area of the village of Itaúnas, which is an important coastal tourist center. The Velha Antônia creek and neighbouring seasonal pools almost disappeared due to recent expansion (Ref. 96072). Also Ref. 27139. + 
Rivulidae Xenurolebias pataxo Costa, 2014 Fr, Thr native   3.18 cm SL male/unsexed ;2.61 cm SL female  Known from a broad coastal plain area between the Jucuruçu river basin (17° 18'58"S 39°13'36"W) and the Mucuri river basin (18° 05'30"S 39° 32'56"W) in southern Bahia state, eastern Brazil, about 95 km in a straight line. Between 1989 and 1998, populations recorded in Jucuruçu, Itanhém and Meio river basins, as well as some populations previously found around the village of Mucuri close to the Mucuri river mouth, have disappeared. The area of occupancy has been tremendously reduced from approximately 200 km2 to a small area of about 10 km2 in the present day. The threats pose by abrupt and extensive environmental degradation suggest that this species should be classified as endangered (Ref. 96072). - 
Poeciliidae Xiphophorus hellerii Heckel, 1848 Fr introduced    14.00 cm TL male/unsexed ;16.00 cm TL female    + 
Poeciliidae Xiphophorus maculatus (Günther, 1866) Fr introduced    4.00 cm TL male/unsexed ;6.00 cm TL female    + 
Aspredinidae Xyliphius anachoretes Figueiredo & Britto, 2010 Fr native   8.84 cm SL male/unsexed  Found only in two localities, one in the upper rio Tocantins (type locality) and the second in the upper rio Araguaia (Ref. 83904). - 
Aspredinidae Xyliphius melanopterus Orcés V., 1962 Fr native    14.70 cm SL male/unsexed   + 
Pimelodidae Zungaro jahu (Ihering, 1898) Fr native  Jau (Portuguese)   140 cm SL male/unsexed  Type locality, Sao Paulo, type unknown. Known from the Paraná-Paraguay River basin. + 
Pimelodidae Zungaro zungaro (Humboldt, 1821) Fr, Fi native  Pacamao (Portuguese), Bagre sapo (Portuguese), Brecumbucu (Portuguese), Dourada (Portuguese), Dourado (Portuguese), Jau (Portuguese), Jaú (Portuguese), Jaú poca (Portuguese), Jundiá (Portuguese), Jundiá de lagoa (Portuguese), Jundiaçu (Portuguese), Manguriú (Portuguese), Moruru (Portuguese), Pacamão (Portuguese), Pacamão do rio (Portuguese), Pacamon (Portuguese), Pacu do rio (Portuguese), Zungaro (Portuguese), Zúngaro (Portuguese)   140 cm SL male/unsexed  During the rainy season, this fish accounts for 30% of all the fish caught in certain fishing areas (Ref. 35381). Regarded as threatened in the state of Minas Gerais (Ref. 26603). Also Ref. 81048. + 
Pimelodidae Zungaropsis multimaculatus Steindachner, 1908 Fr native    Known from Rio Xingu (Ref. 58032). - 
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