>
Gymnotiformes (Knifefishes) >
Gymnotidae (Naked-back knifefishes) > Gymnotinae
Etymology: Gymnotus: Greek, gymnos = naked (Ref. 45335); arapaima: Named for the pirarucu Arapaima gigas (Teleostei: Osteoglossomorpha), referring to the elongate and slightly depressed head, which it resembles. Noun in apposition..
Environment: milieu / climate zone / depth range / distribution range
Sinh thái học
; Nước ngọt gần đáy; pH range: 6.3 - 7.2. Subtropical
South America: Mamirauá lake system, Lago Tefé, and terra firme swamps near the town of Tefé in Central Amazonia.
Bộ gần gũi / Khối lượng (Trọng lượng) / Age
Maturity: Lm ? range ? - ? cm
Max length : 55.0 cm TL con đực/không giới tính; (Ref. 41292); Khối lượng cực đại được công bố: 450.00 g (Ref. 41292)
Short description
Khóa để định loại | Hình thái học | Sinh trắc học
Possess reverse counter shading (lighter on top) in which the dark bands are interrupted dorsally and the pale interband regions merge on the dorsum and in which the dorsum has a silver-blue sheen in life, and very large anterior nares (diameter about that of eye), associated with a large cleft in the anterolateral margin of the ethmoid region resulting in a square anterior margin of snout between the anterior nares. With deep body (body depth 11-13% TL versus 6-10): long head (head length 12.7-13.6% TL versus 8.8-12.6), and depressed head (head depth 53-57% TL versus 58-64) (Ref. 41292).
Facultative air-breathing in the genus (Ref. 126274); Juveniles commonly collected in várzea floating meadows, adults in várzea flooded forest but rarely caught in floating meadows where they are presumed to spawn.
Life cycle and mating behavior
Maturities | Sự tái sinh sản | Spawnings | Egg(s) | Fecundities | Ấu trùng
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)
Threat to humans
Harmless
Human uses
Các công cụ
Special reports
Download XML
Các nguồn internet
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00437 (0.00209 - 0.00911), b=2.98 (2.79 - 3.17), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Mức dinh dưỡng (Ref.
69278): 3.2 ±0.40 se; based on food items.
Thích nghi nhanh (Ref.
120179): Trung bình, thời gian nhân đôi của chủng quần tối thiểu là 1.4 - 4.4 năm (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref.
59153): Moderate vulnerability (42 of 100).
