A new glanapterygine catfish of the genus Listrura (Siluriformes: Trichomycteridae) from southeastern Brazil, corroborated by morphological and molecular data

Abstract

Listrura costai, new species, is described from small streams in a swampy coastal plain in the rio Jurumirim basin, Angra dos Reis Municipality, Rio de Janeiro State, southeastern Brazil. The new species is morphologically very similar to L. nematopteryx and L. picinguabae, all possessing only one long pectoral-fin ray. It differs from its congeners by possessing an autapomorphic character: first hypobranchial with an anterior process (vs. process absent). Other features such as coloration, numbers of opercular and interopercular odontodes, number of anal-fin rays, head length, and shape of some bone structures help to distinguish the new species from L. nematopteryx and L. picinguabae. Molecular analyses using partial sequences of the mitochondrial DNA genes cytochrome oxidase c subunit 1 and cytochrome b from the new species and morphologically similar species are provided. The results about both molecular markers corroborate the validity of the new species by significant genetic distance values between it and congeneric species, and by its phylogenetic position in the hypotheses performed by maximum-parsimony method. © 2012 Sociedade Brasileira de Ictiologia.