Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Characiformes
(Characins) > Characidae
(Characins) > Rhoadsiinae
Etymology: Nematocharax: Greek, nemas, -atos = filament + Greek, charax = a marine fish without identification (Ref. 45335); costai: Named for Wilson Costa, notably known for his great contribution in Ichthyology and for his main role in planning the expedition and first to recognize the new species in the field.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
South America: Cambiriba Stream, Balneário Guaíra, middle Contas River basin in northeastern Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 5.0 cm SL male/unsexed; (Ref. 93323)
Morphology | Morphometrics
Vertebrae: 33. Distinguished by having the following unique combination of characters: dorsal, anal and pelvic fins with elongated branched rays; two rows of premaxillary teeth in adults, and an almost complete row of teeth along the free ventral maxillary border. Differs from its unique congener, Nematocharax venustus, by having the following characters: absence of hooks or spinules on dorsal and pelvic-fins (vs. presence); five anal-fin rays with spinules (vs. more than seven rays); presence of a long dark pink horizontal mark on the caudal peduncle (vs. absence); five supraneurals (vs. four or fewer); pelvic-fin filament yellow (vs. pale rosy) (Ref. 93323).
Occurs in sandy bottom fast running water stream, with about 7 m width, 1 m depth and pale brown and turbid water. Found under marginal vegetation (Ref. 93323).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Bragança, P.H.N., M.A. Barbosa and J.L. Mattos, 2013. A new Nematocharax species from the middle Contas River basin, northeastern Brazil (Characiformes: Characidae). Verteb. Zool. 63(1):3-8. (Ref. 93323)
IUCN Red List Status (Ref. 115185)
CITES (Ref. 115941)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.7500 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01995 (0.00906 - 0.04395), b=3.01 (2.83 - 3.19), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.1 ±0.3 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .