Description of a new species of the catfish genus Trichomycterus (Teleostei: Siluriformes: Trichomycteridae) from the rio de Contas basin, northeastern Brazil

Abstract

Trichomycterus tete, new species is described from the upper rio de Contas basin, northeastern Brazil. It is the first record of the genus to the Caatinga semi-arid region. The new species is distinguished from all its congeners by having a combination of eight pectoral-fin rays, the first pectoral-fin ray prolonged as a filament, metapterygoid deeper than wide, short maxillary barbel reaching the middle of opercular patch of odontodes, narrow head (head width 68.07 - 77.5% HL), 11 dorsal-fin rays, caudal fi n truncated, body slender (body depth 12.3 - 13.6% SL), shorter dorsal-fin base (dorsal-fin base length 9.5 - 11.4% SL), and an uncommon color pattern. In addition, T. tete differs from all the congeners from southeastern Brazil by having a deep area at the external edge of the hypobranchial 1.