A new miniature Pristella (Actinopterygii: Characiformes: Characidae) with reversed sexual dimorphism from the rio Tocantins and rio Sao Francisco basins, Brazil

摘要

A new species of the genus Pristella Eigenmann, 1908 ( Pristella crinogi sp. nov.) is described from the middle rio Tocantins and middle rio Sao Francisco basins, Brazil. The new species can be diagnosed from its two congeners, Pristella ariporo Conde- Saldana, Albornoz-Garzon, Garcia-Melo, Villa-Navarro, Mirande, and Lima, 2019 and Pristella maxillaris (Ulrey, 1894), by a combination of color pattern and teeth morphology characters. A phylogenetic analysis of the genus recovered P. crinogi as the sister taxa of P. ariporo. Pristella crinogi, along with P. ariporo, are the first characiform fishes, and one of the first bony fishes, to be reported as presenting a reversed sexual dimorphism, with females presenting a more developed color pattern than males. Comments on theminiaturization of the species, as well as remarks on the biogeography of the genus Pristella, are presented.