A new species of tetra in the genus Astyanax has been described from Uruguay.
Mara Azpelicueta and Marcelo Loureiro name the new species Astyanax laticeps in the most recent issue of the journal Vertebrate Zoology. The new species can be distinguished from congeners by its slender body (28.2"37.3% standard length), blunt snout, 1"4 maxillary teeth, 18"24 branched anal-fin rays, 36"39 perforated scales along the lateral line, short caudal peduncle (12.6"13.7% standard length), dorsal-fin origin nearer the snout than the origin of the procurrent caudal-fin rays, a horizontally ovoid or rounded humeral spot surrounded by a pale area, and mature males with bony hooks on branched pelvic-fin rays and anteriormost anal-fin rays.
For more information, see the paper: Azpelicueta M de las M and M Loureiro (2009) Astyanax laticeps (Teleostei: Characiformes: Characidae) from rivers and streams of Uruguay. Vertebrate Zoology 59, pp. 3"9.