Two new species of Astyanax (Ostariophysi: Characiformes: Characidae) from eastern Brazil, with a synopsis of the Astyanax scabripinnis species complex

Abstract

Two new species of Astyanax are described from eastern Brazil: A. microschemos from the córrego Palmital, rio Itapemirim drainage, Espírito Santo, and A. pelecus from the rio Pardo drainage, Bahia. Astyanax microschemos differs from its congeners by its shallower body depth, 26.9-29.7% of standard length, the presence of one vertically elongate humeral spot that extend above and below the lateral line, smaller interorbital width, 26.9-30.4% of head length, and the possession of 14-18 branched anal-fin rays. Astyanax pelecus differs from its congeners in the possession of only one humeral spot limited to the region dorsal to the lateral line, conspicuous, dark, midlateral body stripe extending from the upper margin of the opercle to the caudalfin base, a shallower body depth, 26.7-34.8% of standard length, and the possession of 16-18 branched anal-fin rays, 38-39 scales in the lateral-line series, and four scales between the lateral line and the pelvic-fin origin. Astyanax microschemos has a massive head, short snout, usually smaller than the orbital diameter, shallow body depth, and vertically-elongate humeral spot that serve to include it in the A. scabripinnis species complex. A comparative synopsis of this complex is provided. Copyright © 2006 Sociedade Brasileira de Ictiologia.