A New Species ofRhamphichthys(Gymnotiformes: Rhamphichthyidae) from the Amazon Basin

Abstract

Rhamphichthys heleios, new species, is described from the Amazon Basin in Brazil, being known from lakes and channels associated with the floodplains of large rivers. The new species is readily distinguished from all other congeners by a unique color pattern, composed of a series of dark irregular rounded blotches along the lateral body surface over the lateral line, and by the absence of clearly formed saddles across the dorsum. Comments on the taxonomy and use of color pattern for the systematics of Rhamphichthys are made based on examination of extensive materials in museum collections, and a key to the species of the genus occurring in the Amazon Basin is provided. Rhamphichthys heleios, especie nova, e descrita para a Bacia Amazonica no Brasil, sendo encontrada em lagos e canais juntos a planicie de inundacao de grandes rios. A especie nova se diferencia das demais especies de Rhamphichthys pelo seu padrao de colorido unico que e composto por uma serie de manchas escuras arredondadas na lateral do co...