new species from Argentina:
Astyanax chico Casciotta & Almirón, 2004

type locality:
province of Jujuy, río San Francisco basin, río de Zora in route 34; holotype: MACN-Ict 8673, 60.0 mm SL

published in:
Casciotta, J.R. & A.E. Almirón (2004):
Astyanax chico sp.n. – a new species from the río San Francisco basin, northwest of Argentina (Teleostei: Characiformes: Characidae).
Zoologische Abhandlungen des Staatlichen Museums für Tierkunde, Dresden 54: 11-17

abstract (from publication):
Astyanax chico is described from two tributaries of the río San Francisco located in the northwestern part of Argentina. Astyanax chico bears hooks on all fin rays of males like A. ojira, A. pynandi, A. stenohalinus, and A. troya. Astyanax chico is distinguished from the remaining species of the genus by the following combination of characters: one maxillary tooth with 2 to 4 cusps; teeth of inner premaxillary row expanded distally, deep dentary bearing 7 teeth decreasing in size anteroposteriorly; males with hooks in all fins; 35-39 perforated scales in lateral series; iii-iv, 19-24 anal fin rays. One humeral spot vertically elongated, a second lateral spot may be faint or well developed.

distribution (from publication):
Astyanax chico sp.n. is known from the río de Zora and arroyo Saladillo, both affluents of the río San Francisco.