Scientists from Brazil, the USA and Venezuela have described a new species of doradid catfish with an unusual proboscoid mouth in the latest issue of the journal Copeia.
The new species, named Rhynchodoras castilloi, is described from the Apure River (part of the Orinoco River drainage) in Venzuela by José Birindelli, Mark Sabaj and Donald Taphorn.
There are two other species of Rhynchodoras: R. woodsi from the Essequibo and Amazon river drainages excluding the Xingu and Tocantins river drainages, and R. xingui from the Xingu and Tocantins river drainages.
Rhynchodoras castilloi (the species is named after Venezuela biologist Otto E. Castillo G.) differs from R. woodsi in having a simple gas bladder and punctate, abundant tubercles on the body, and from R. xingui in having all three tympanal scutes weakly developed, 34–36 (modally 35) midlateral scutes, and shallow anterior midlateral scutes with weakly developed dorsal and ventral laminae lacking distinct serrations along posterior margins.
All of the specimens of R. castilloi studied were collected by bottom trawling, suggesting that this is a species that inhabits only deep water.
The authors also consider Rhynchodoras to be closely related to Rhinodoras and Orinocodoras.
For more information, see the paper: Birindelli, JLO, MH Sabaj and DC Taphorn (2007) New species of Rhynchodoras from the Río Orinoco, Venezuela, with comments on the genus (Siluriformes: Doradidae). Copeia 2007, 672–684.