Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Characiformes
(Characins) > Characidae
(Characins) > Incertae sedis
Etymology: Oligosarcus: Greek, oligos = small + Greek arkos = anus (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Subtropical
South America: southeastern Brazil and the La Plata basin.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 32.0 cm TL male/unsexed; (Ref. 111130)
Morphology | Morphometrics
Occurs in ponds (Ref. 11229). Inhabits shallow, densely vegetated microhabitats in small streams or along the banks of larger rivers (Ref. 106564). Feeds mostly on fishes (Ref. 598). Two rodents (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 represent the first records of this species feeding on mammals (Ref. 106564).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Géry, J., 1977. Characoids of the world. Neptune City ; Reigate : T.F.H. [etc.]; 672 p. : ill. (chiefly col.) ; 23 cm. (Ref. 598)
IUCN Red List Status (Ref. 115185)
CITES (Ref. 115941)
Threat to humans
Fisheries: of no interest
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00794 (0.00492 - 0.01282), b=3.02 (2.89 - 3.15), in cm Total Length, based on LWR estimates for this species & Genus-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 4.2 ±0.73 se; Based on food items.
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low vulnerability (22 of 100) .