Batrochoglanis

Taxobox
name = "Batrochoglanis"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = Pseudopimelodidae
genus = "Batrochoglanis"
genus_authority = Gill, 1858
subdivision_ranks = Binomial name
subdivision =
"Batrochoglanis acanthochiroides"
(Güntert, 1942)
"Batrochoglanis melanurus"
Shibatta & Pavanelli, 2005
"Batrochoglanis raninus"
(Valenciennes, 1840)
"Batrochoglanis transmontanus"
(Regan, 1913)
"Batrochoglanis villosus"
(Eigenmann, 1912)

"Batrochoglanis" is a small genus of catfishes (order Siluriformes) of the family Pseudopimelodidae.

Distribution

"Batrochoglanis" species are known and distributed throughout the Amazon basin, rivers of the Ecuadorian and Colombian Pacific coast, the northern region of South America, and the Paraguay River basin. "B. acanthochiroides" is distributed in the Catatumbo River basin of the Maracaibo basin.FishBase species|genus=Batrochoglanis|species=acanthochiroides|year=2007|month=June] "B. melanurus" is only known from its type locality in the Paraguay River basin of Brazil. "B. raninus" is found in the Amazon River basin, Guyana, and French Guiana.FishBase species|genus=Batrochoglanis|species=raninus|year=2007|month=June] "B. transmontanus" originates from Baudó, San Juan, Patia and Durango River basins.FishBase species|genus=Batrochoglanis|species=transmontanus|year=2007|month=June] "B. villosus" is found in the Demerara River of the Essequibo basin, Orinoco, and Amazon River basins.

Description

Species of this genus have rounded, wider than deep bodies; large heads, rounded in dorsal view; pelvic fins originating at vertical line through the end of the dorsal fin; short caudal peduncles, with caudal fin procurrent rays close to adipose and anal fins; emarginated caudal fins, with rounded lobes, or completely rounded; incomplete lateral lines, sometimes surpassing the adipose-fin end, but never reaching the caudal fin.cite journal|url=http://www.mapress.com/zootaxa/2005f/zt01092p030.pdf|title=Description of a new "Batrochoglanis" species (Siluriformes, Pseudopimelodidae) from the rio Paraguai basin, State of Mato Grosso, Brazil|first=Oscar Akio|last=Shibatta|coauthors=Pavanelli, Carla Simone|journal=Zootaxa|volume=1092|pages=21–30|year=2005|format=PDF]

Three color patterns of the caudal fin in "Batrochoglanis" species are known. The first pattern, in "B. raninus", "B. transmontanus" and "B. acanthochiroides", is a light caudal fin, with a dark band on the posterior third. The second pattern, in "B. villosus", is a light caudal fin, with dark dots irregularly distributed. The third pattern, found in "B. melanurus", has the caudal fin completely dark. The coloration pattern is useful for separating species, but apparently does not allow inferences about phylogenetic relationships to be safely made, since this character is widespread in this family.

"B. acanthochiroides", the largest species, grows to 80.0 centimetres (31 in) TL. "B. melanurus" has a maximum length of 13.7 cm (5.39 in) SL. "B. raninus" reaches a length of 20.0 (7.87 in) SL. "B. transmontanus" grows to a length of 25.0 cm (9.84 in) TL. "B. villosus" reaches a length of 14.8 cm (5.83 in) TL.

Ecology

"B. transmontanus" is recorded to live in rivers.FishBase species|genus=Batrochoglanis|species=villosus|year=2007|month=June] "B. raninus" commonly occurs in creeks as well as in rivers. It is found in very shady, deep zones of rivers where the current is slow, the bottom is shady, and the gravel is covered with plant debris. During the day, "B. raninus" lies hidden under branches or rocks. It hunts by stalking, swallowing prey within its range. When young, "B. raninus" feeds on micro-crustaceans and aquatic insect larvae, then shifts it diet to fishes of notable size.

References