Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Cyprinodontiformes
(Rivulines, killifishes and live bearers) > Rivulidae
Etymology: Rivulus: Latin, rivus = stream (Ref. 45335); formosensis: The specific name formosensis alludes to the occurrence of the species in the Formoso river floodplains. More on author: Costa.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic; pH range: 5.6 - ?. Tropical
South America: Formoso river floodplains, upper Corrente river drainage of the upper Paraná river basin in Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 3.3 cm SL male/unsexed; (Ref. 75995); 3.5 cm SL (female)
Morphology | Morphometrics
soft rays: 13 - 15;
Vertebrae: 30. Diagnosed from all congeners by the presence of red marks on flank arranged in chevron-like pattern with a branching on the upper portion forming Y-shaped red marks in males. Additional characters not unique but useful to distinguish from all congeners when combined include: flank intense greenish blue, to purplish blue above anal-fin base in males; red marks on flank arranged in chevron-like pattern; sub-basal red stripe on the dorsal fin absent in males; absence of black reticulation on head in females; absence of orange pigmentation on caudal fin in females; 29-31 scales in the longitudinal series; frontal squamation E-patterned; 31-33 caudal-fin rays; pre-dorsal length 75.1-79.5% SL in males; and anal-fin base 20.6-23.0% SL in males; 18.2-20.0% SL in females (Ref. 75995).
Inhabits open areas highly exposed to sunlight (Ref. 75995).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Costa, W.J.E.M., 2008. Rivulus formosensis, a new aplocheiloid killifish from the upper Corrente River drainage, upper Paraná River basin, central Brazil (Cyprinodontiformes: Rivulidae). Ichthyol. Explor. Freshwat. 19(1):85-90. (Ref. 75995)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 118484)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5010 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00479 (0.00199 - 0.01154), b=3.14 (2.93 - 3.35), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.1 ±0.4 se; Based on size and trophs of closest relatives
Resilience (Ref. 120179
): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .