Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Gymnotiformes
(Knifefishes) > Gymnotidae
Etymology: Gymnotus: Greek, gymnos = naked (Ref. 45335); jonasi: Named in honor of Jonas Alves de Oliveira, a Brazilian naturalist working for the Mamirauá Sustainable Development Reserve (Ref. 41292).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Subtropical
South America: Amazon River basin, Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 13.5 cm TL male/unsexed; (Ref. 41292); max. published weight: 4.00 g (Ref. 41292)
Morphology | Morphometrics
Electric organs present.
Recorded from root mass of floating meadows in the whitewater floodplains of the Tefé region where it is common although patchy in distribution. Adults both breed and forage in the meadows and are never encountered in other floodplain habitats such as flooded forests. Both juveniles and adults feed on small aquatic animals, especially chironomid larvae (Ref. 41292).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Albert, J.S. and W.G.R. Crampton, 2001. Five new species of Gymnotus (Teleostei: Gymnotiformes) from an upper Amazon floodplain, with descriptions of electric organ discharges and ecology. Ichthyol. Explor. Freshwat. 12(3):241-266. (Ref. 41292)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 115941)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg 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=0.00589 (0.00178 - 0.01947), b=2.97 (2.71 - 3.23), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 2.5 ±0.50 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 (13 of 100) .