Scientists from Argentina have described a new species of Astyanax from the Sal River drainage in northwestern Argentina.
The new species, named Astyanax puka, is described in the latest issue of the journal Zootaxa by Juan Mirande, Gastn Aguilera and Mara Azpelicueta.
Astyanax puka is distinguished from other members of the genus in having the following combination of characters: shallow body (33.5"39.8 % SL), 36"38 perforated scales in lateral line, 6/5 transverse scales, 9"10 dentary teeth that gradually decrease in size, distally expanded premaxillary teeth, one distally expanded maxillary tooth with 7"9 cusps, short upper-jaw length (34.5"37.8 % HL), short maxilla (20.7"23.3 % HL) expanded abruptly under maxillary tooth position, short postorbital distance (36.6"46.9 % HL), short pelvic to anal-fin origin distance (17.1"20.6 % SL), 22"27 branched anal-fin rays, long caudal peduncle (13.3"16.5 % SL), bony hooks restricted to pelvic-fin rays two to six and anterior 6"13 branched anal-fin rays on mature males, and the presence of broad denticles on anterior, lateral, and posterior edges of first ceratobranchial gill rakers.
The new species is restricted to the Sal River drainage, which flows into the Hondo River reservoir in northwestern Argentina.
For more information, see the paper: Mirande, JM, G Aguilera & M de la M Azpelicueta (2007) A new species of Astyanax (Characiformes: Characidae) from the endorheic Ro Sal basin, Tucumn, northwestern Argentina. Zootaxa 1646, pp. 31"39.