A new species of Astyanax (Characiformes, Characidae) from the rio Apiacás, rio Teles Pires basin, with a discussion on its phylogenetic position

Abstract

A new species of Astyanax is described from the rio Apiacás, a tributary of the rio Teles Pires, rio Tapajós basin, Mato Grosso state, Brazil. The new taxon can be distinguished from all congeners, except those belonging to the Astyanax bimaculatus species group and to the A. orthodus species group, by the presence of a horizontally elongated, rounded humeral blotch. The new taxon can be readily distinguished from all species belonging to the Astyanax bimaculatus species group and to the A. orthodus species group by presenting a pointed snout and by a distinct morphology in premaxillary and dentary teeth. We also present a hypothesis about the phylogenetic relationships of the new taxon within Astyanax.