Pterodoras

Taxobox
name = "Pterodoras"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = Doradidae
genus = "Pterodoras"
genus_authority = Bleeker, 1862
binomial = "Pterodoras granulosus"
binomial_authority = (Valenciennes, 1821)
binomial2 = "Pterodoras rivasi"
binomial2_authority = (Fernández-Yépez, 1950)
synonyms =
* "Apuredoras"
Fernández-Yépez, 1950
* "Parapterodoras"
Risso & Morra, 1964
* "Sachsdoras"
Fernández-Yépez, 1968

"Pterodoras" is a small genus of catfishes (order Siluriformes) of the family Doradidae. This genus includes two species, "P. granulosus" and "P. rivasi".cite journal|url=http://silurus.acnatsci.org/ACSI/library/biblios/2007_Ferraris_Catfish_Checklist.pdf|title=Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types|first=Carl J., Jr.|last=Ferraris|journal=Zootaxa|volume=1418|pages=1 – 628|year=2007|format=PDF]

Distribution

"P. granulosus" originates from the Amazon and Paraná River basins and coastal drainages in Guyana and Suriname. "P. rivasi" inhabits the Orinoco River basin of Colombia and Venezuela.

Physical description

"P. granulosus" reaches a size of 70 centimetres (28 in) TL and 6,500 grams (14 lb).FishBase species|genus=Pterodoras|species=granulosus|year=2007|month=June] The colour pattern of these catfish varies depending upon the location that they originate from, though they are usually a muddy-brown colour with some darker spots over the body and fins. Adults are darker and the spotting fades from juvenile coloration. There are no scales, but the skin is thick and tough; also, 23–28 shallow lateral plates known as scutes are found along the length of the body. Their eyes are very small in comparison to the rest of the fish and they have three simple pairs of barbels. They have a deeply forked caudal fin, which also helps to distinguish this fish from other large Doradids.cite web|url=http://www.planetcatfish.com/cotm/cotm.php?article_id=139|title=PlanetCatfish::Catfish of the Month::September 2002|publisher=PlanetCatfish.com|date=2005-06-17|accessdate=2007-06-21]

"P. rivasi" grows to 55 cm (22 in) SL.FishBase species|genus=Pterodoras|species=rivasi|year=2007|month=June]

Ecology

"P. granulosus" occurs in small groups.

"P. granulosus" is a nocturnal predator. It is an opportunistic omnivore with a wide food spectrum, consuming vascular plants, mollusks, and other food depending on their availability. It has been shown that this species feeds on an introduced species of bivalve, "Corbicula fluminae", and may be able to act as a form of biological pest control. [cite journal|url=http://www.ppg.uem.br/docs/ctf/Biologicas/2002/22_270_01_Karla%20Luz%20e%20outros_Alterations%20in%20the.pdf|title=Alterations in the "Pterodoras granulosus" (Valenciennes, 1833) (Osteichthyes, Doradidae) diet due to the abundance variation of a bivalve invader species in the Itaipu Reservoir, Brazil|first=Karla Danielle|last=Gaspar da Luz|coauthors=Fugi, Rosemara; Abujanra, Fabiane; Agostinho, Angelo Antonio|journal=Maringá|volume=24|issue=2|pages=427–432|year=2002|format=PDF] There is evidence that "P. granulosus" may be important for seed dispersal as seeds have been found in their stomachs; seeds of the families Gramineae, Moraceae, and Polygonaceae are most often present in their stomachs.cite journal|title=Seed Dispersal by the Fish "Pterodoras granulosus" in the Parana River Basin, Brazil|first=Maria Conceicao|last=de Souza-Stevaux|coauthors=Negrelle, Raquel R. B.; Citadini-Zanette, Vanilde|journal=Journal of Tropical Ecology|year=1994|volume=10|pages=621–626]

"P. granulosus" is a migratory species of catfish. From March to July, there is little migration and any movement is downstream. In August, the upstream migration begins, intensifying in October and peaking in January.

References