New neoplecostomine genus and species

[Silurus]

Pereira, EHL, A Zanata, M Cetra & RE Reis, 2014. A remarkable sexually dimorphic new genus and species of neoplecostomine catfish (Siluriformes, Loricariidae) from a coastal drainage of eastern Brazil. Copeia 2014: 673–681.

Abstract

A new neoplecostomine genus and species is described from headwater tributaries of the lower Rio Pardo basin, a coastal drainage in Bahia, eastern Brazil.

Hirtella carinata

is a small loricariid with a maximum standard length barely reaching 50 mm. The new genus and species are diagnosed among all other loricariids by a unique, remarkable pattern of sexual dimorphism in which adult males have five conspicuous longitudinal rows of bristle-like hypertrophied odontodes on the head and along the lateral dermal plates of the body. Hirtella is further distinguished from most loricariids by the anterior position of the pelvic fin, which originates in a vertical anterior to the nuchal plate, and by the possession of an elongate keel formed by 15–17 azygous plates along the mid-dorsal line between the dorsal and the caudal fins. Hirtella is additionally distinguished from other members of the Neoplecostominae by having a medium sized palatine splint, never reaching the anterior border of the nasal fossa. Phylogenetic analysis indicates that Hirtella is the sister taxon of Pareiorhina. The description of this new genus raises to six the number of currently recognized genera in the Neoplecostominae.