Revisão das espécies nominais do gênero Proloricaria Isbrücker, 2001 (Siluriformes: Loricariidae, Loricariinae): um caso de aplicação de taxonomia integrativa

Abstract

The catfishes of the Loricariinae subfamily inhabit the substrate environments of South American rivers and are distinguished from the rest of the Loricariidae family by having a long, depressed caudal peduncle and the absence of an adipose fin. Most of the more than 250 species of Loricariinae were described in the genus Loricaria, but many are currently located in other genera of the subfamily. The genus Proloricaria was described in 2001, having as type species Loricaria prolixa, from the Tietê river basin. The other species accepted for the genus, Proloricaria lentiginosa, was originally described as L. prolixa lentiginosa, from specimens of the rio Grande basin. The two species are widely distributed in the upper rio Paraná basin, and are morphologically very similar. The distinction between them was originally based on the difference of color on the head and body, and the arrangement of bony plates on the abdomen. Such characters are labile, with doubts regarding the recognition and taxonomic validity of the two species, suggesting synonymy. This monograph consists in a study of the species of the genus Proloricaria using a combination of morphological methods and molecular analysis (DNA barcoding), in order to test the hypothesis of validity of two nominal species belonging to the genus. Morphometric, meristic and qualitative analyzes of specimens deposited in collections were carried out, as well as molecular analyzes of DNA barcoding from the sequencing of the Cytochrome Oxidase I (COI) gene of specimens, comparing them with the sequences available at BOLD Systems and Genbank. The morphological analysis of the species showed differences regarding the presence or absence of a pair of pre-dorsal supernumerary anterior plates, and the number of rows of odontodes on the parieto-supraoccipital. Molecular analyzes of the sequences compared with the database sequences allowed the distinction of the two species, supporting the necessity of correction of the mentions of both in the studies of the ichthyofauna of the upper Paraná river. The morphological and molecular basis obtained in this study resolves many of the existing conflicts regarding the identification and validity of the species, presents support to distinguish them as two different species, corrects the mentions of each one of them in the literature, and defines the distribution pattern of P. prolixa in the Tietê, Paranapanema and Paraná river basins, and P. lentiginosa in the rio Grande basin, both integrating the upper Paraná river system.