Taxonomic review of gender species astyanax baird and girard, 1854, (teleostei: characiformes: characidae) region of Serra dos Órgãos

Abstract

The species of the genus Astyanax Baird and Girard (1854) from the region of the Serra dos Órgãos, part of Serra do Mar in the State of Rio de Janeiro, Brazil, are reviewed. Astyanax giton Eigenmann (1908), A. hastatus Myers (1928), A. janeiroensis Eigenmann (1908) and A. taeniatus (Jenyns, 1842) are redescribed. Astyanax fasciatus parahybae Eigenmann, (1908) and A. scabripinnis intermedius Eigenmann (1908) are elevated to species category. Astyanax parahybae differs from the Astyanax fasciatus (Cuvier, 1819) species complex by the presence of scales irregulary arranged above the anal fin. Astyanax intermedius differs from A. scabripinnis (Jenyns, 1842) by the shape of dentary teeth, whose height varies abruptally beyond the fifth tooth. Dentary tooth height of A. scabripinnis varies abuptly from the fourth teeth. Astyanax giton, A. intermedius and A. parahybae have their lectotypes designated. Two possibly new species are recognised. Astyanax sp.1, diagnosed by the presence of imbricate predorsal scales, ovate umeral spot and the absence of maxillary teeth, belongs to the species group complex A. bimaculatus. Astyanax sp.2 caracterized as belonging to A. fasciatus species complex, diferenciates from A. parahybae total by smaller number of total anal fin rays, 24-26, and by the presence of scales regulary arranged above the anal fin. Distribution maps and a identification key are furnished.