Revisão taxonômica do gênero Pimelodella Eigenmann & Eigenmann, 1888 (Ostariophysi: Siluriformes: Heptapteridae) das bacias hidrográficas do estado do Espírito Santo (Brasil)

Abstract

Pimellodella Eigenmann & Eigenmann, 1888 is a genus of neotropical catfishes composed of 72 species distributed from Panama to Argentina. However, data on the genus in the state of Espírito Santo were scarce until 2009. The lack of access to the holotypes and the only two recent revisions in the 20th century, cause a divergence between the researchers in the identification of the species. Based on this information, the present study a review of the species of the genus Pimelodella found in the basins of the State of Espírito Santo based on specimens registered in scientific collections. The external morphological characteristics (morphometric, anatomical and color pattern) and osteological characteristics were used for characterization, identification and description of the samples examined. The data indicated a link of two new species in the state. Pimelodella sp.1 differs from other species of Pimelodella, except for Pimelodella sp. 2, due to its long snout, short head, and five branchyostegal rays, and the Pimelodella differentiation is presented by a pair of S6 pores, large interorbital and small eyes. Pimelodella sp. 1 occur in the basins of the Reis Magos, São Mateus and Itaúnas rivers are registered in the oldest geological event observed in the studied basins, the Nova Venécia complex, and is located in rapids regions, preferring the fast flow with moderate relief. Pimelodella sp. 2 differs from other species of Pimelodella, with the exception of Pimelodella sp.1, for presenting the long snout, short head, and five gill rays, and the differentiation of Pimelodella sp.1 by presenting a single pore S6, short interorbital space and large eyes. In the occur in the basins of Barra Seca, Beneventes, Doce, Itaúnas, São Mateus, Itabapoana and Itapemirim. It is located in a region of more recent geological events, it is related to the sediments of the coast and is in slowness in regions of plain along the Espírito Santo.