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Teleostei (teleosts) > Gymnotiformes (Knifefishes) > Gymnotidae (Naked-back knifefishes) > Gymnotinae
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).
Eponymy: Jonas Alves de Oliveira is a naturalist and technician at Mamirauá Sustainable Development Reserve, Amazonas, Brazil. He co-wrote: Chromosomal diversity in three species of electric fish (Apteronotidae, Gymnotiformes) from the Amazon Basin (2014). (Ref. 128868), visit book page.

Environment: milieu / climate zone / depth range / distribution range Ecology

Freshwater; benthopelagic. Subtropical

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

South America: Amazon River basin, Brazil.

Size / Weight / Age

Maturity: L_m ? range ? - ? cm
Max length : 13.5 cm TL male/unsexed; (Ref. 41292); max. published weight: 4.00 g (Ref. 41292)

Short description Identification keys | Morphology | Morphometrics

Electric organs present.

Facultative air-breathing in the genus (Ref. 126274); 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

Main reference Upload your references | References | Coordinator : Campos-da-Paz, Ricardo | Collaborators

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. 130435: Version 2024-1)

Least Concern (LC) ; Date assessed: 01 March 2007

CITES

Not Evaluated

CMS (Ref. 116361)

Not Evaluated

Threat to humans

Harmless

Human uses

FAO - Publication: search | FishSource |

More information

Trophic ecology
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Ecology
Ecology

Population dynamics
Growth parameters
Max. ages / sizes
Length-weight rel.
Length-length rel.
Length-frequencies
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Abundance

Life cycle
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Maturity/Gills rel.
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Eggs
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Anatomy
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Estimates based on models

Phylogenetic diversity index (Ref. 82804): PD₅₀ = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].

Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm total length, based on all LWR estimates for this body shape (Ref. 93245).

Trophic level (Ref. 69278): 2.5 ±0.50 se; based on food items.

Resilience (Ref. 120179): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).

Fishing Vulnerability (Ref. 59153): Low vulnerability (10 of 100).

Gymnotus jonasi Albert & Crampton, 2001