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> Gymnotiformes (Knifefishes) > Gymnotidae (Naked-back knifefishes) > Gymnotinae
Etymology: Gymnotus: Greek, gymnos = naked (Ref. 45335); varzea: Named for the whitewater várzea floodplain, which this species is restricted to..

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

; acqua dolce benthopelagico. Tropical

Distribuzione Stati | Aree FAO | Ecosystems | Presenze | Point map | Introduzioni | Faunafri

South America: Amazon basin in Brazil and Peru.

Size / Peso / Age

Maturity: L_m ? range ? - ? cm
Max length : 28.5 cm TL maschio/sesso non determinato; (Ref. 55508); peso massimo pubblicato: 65.00 g (Ref. 55508)

Short description Morfologia | Morfometria

Spine dorsali (totale): 0; Raggi dorsali molli (totale): 0; Raggi anali molli: 230 - 310. Distinguished from its congeners endemic to the Amazon and Orinoco Basins and the Guyana Shield in having a color pattern of 16-22 oblique dark pigment bands with wavy and irregular margins in which the majority of bands at midbody form X-shaped patterns (resembling metaphase chromosomes) and in which the dark bands are about twice as broad as the pale interbands. Further differs from its congeners in having the following unique combination of characters: clear (unpigmented) patch at the caudal end of the anal-fin membrane in specimens 6.0-23.7 cm; and bands never divided to form band pairs (Ref. 55508).

Facultative air-breathing in the genus (Ref. 126274); Found in root mats of floating meadows in floodplains (Ref. 55508). Gulps atmospheric air into the hypervascularized posterior chamber of its gas bladder (Ref. 55508). Feeds on small aquatic invertebrates such as chironomid larvae, insect nymphs and microcrustaceans (Ref. 55508).

Life cycle and mating behavior Maturità | Riproduzione | Deposizione | Uova | Fecundity | Larve

Main reference Upload your references | Bibliografia | Coordinatore : Campos-da-Paz, Ricardo | Collaboratori

Crampton, W.G.R., D.H. Thorsen and J.S. Albert, 2005. Three new species from a diverse, sympatric assemblage of the electric fish Gymnotus (Gymnotiformes: Gymnotidae) in the lowland Amazon basin, with notes on ecology. Copeia 2005(1):82-99. (Ref. 55508)

IUCN Red List Status (Ref. 130435)

Least Concern (LC) ; Date assessed: 14 August 2020

CITES

Not Evaluated

CMS (Ref. 116361)

Not Evaluated

Threat to humans

Harmless

Human uses

FAO - Publication: search | FishSource |

Informazioni ulteriori

Stati
Aree FAO
Ecosystems
Presenze
Introduzioni
Stocks
Ecologia
Dieta
Prede
Consumo di cibo
Razione

Nomi Comuni
Sinonimi
Metabolismo
Predatori
Ecotossicologia
Riproduzione
Maturità
Deposizione
Spawning aggregation
Fecundity
Uova
Egg development

Age/Size
Accrescimento
Length-weight
Length-length
Length-frequencies
Morfometria
Morfologia
Larve
Dinamica popolazioni larvali
Reclutamento
Abbondanza
BRUVS

Bibliografia
Acquacoltura
Profilo di acquacoltura
Varietà
Genetica
Electrophoreses
Ereditarietà
Malattie
Elaborazione
Nutrients
Mass conversion

Collaboratori
Immagini
Stamps, Coins Misc.
Suoni
Ciguatera
Velocità
Modalità di nuoto
Area branchiale
Otoliths
Cervelli
Vista

Strumenti

Special reports

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Fonti Internet

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): 3.2 ±0.40 se; based on food items.

Resilienza (Ref. 120179): Alto, tempo minimo di raddoppiamento della popolazione meno di 15 mesi (Preliminary K or Fecundity.).

Fishing Vulnerability (Ref. 59153): Low vulnerability (19 of 100).

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Gymnotus varzea Crampton, Thorsen & Albert, 2005