Gymnotus
varzea
Crampton, Thorsen & Albert, 2005
| |
|
Family:
|
Gymnotidae
(Naked-back knifefishes)
|
 |
Google Image (not verified)
May show another species!
|
|
|
Order:
|
Gymnotiformes
(knifefishes)
|
|
Class:
|
Actinopterygii (ray-finned fishes)
|
|
In this site name:
|
|
|
Max. size:
|
28.5 cm TL (male/unsexed; Ref. 55508); max. published weight: 65.0 g (Ref. 55508) |
|
Environment: |
benthopelagic; freshwater
|
|
Climate: |
tropical |
|
Importance:
|
|
|
Resilience: |
High, minimum population doubling time less than 15 months(Preliminary K or Fecundity.)
|
Distribution:
|
South America: Amazon basin in Brazil and Peru.
|
|
Morphology:
|
Dorsal
spines
(total): 0 - 0;
Dorsal
soft rays
(total): 0 - 0;
Anal
soft rays: 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).
|
|
Biology: |
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).
|
|
Red List Status: |
Not in IUCN Red List (Ref. 57073)
|
|
Dangerous:
|
harmless
|
|
Coordinator:
|
