On the identity of Corydoras nattereri Steindachner, 1877 with the description of a new species, Corydoras prionotos (Pisces, Siluriformes, Callichthyidae)

A redescription and figures of Corydoras nattereri Steindachner, 1877, are given together with a description and figures of a new species, Corydoras prionotos, sympatric with Corydoras nattereri, with comparable dimensions and a similar colour pattern. A total of 1066 specimens were examined, including primary type-material of Corydoras juquiaae Von Ihering, 1907, and of Corydoras nattereri triseriatus Von Ihering, 1911, which are both placed in synonymy of C. nattereri, the holotype of which is lost. A neotype for Corydoras nattereri is designated. Corydoras prionotos differs from C. nattereri mainly in having the medial border of the pectoral-fin spine strongly serrate.