Astyanax stenohalinus

description

new combination from Astyanax info published in Terán et al. (2020)

CLOFFUY - update 5 - supplement to Checklist of the Freshwater Fishes of Uruguay.

Astyanax stenohalinus Messner 1962

A. stenohalinus Messner, 1962 First record from Argentina> details

List of Freshwater Fishes from Argentina - Update 9.

description

Description: Morphometrics of holotype and 14 specimens are presented in Table 1. Body relatively deep, especially in females (Fig. 2), with maximum body depth located immediately anterior to dorsal-fin origin. Dorsal profile of body curved from snout tip to dorsal-fin origin, with concavity over supraoccipital area (Fig. 3); straight and slanted ventrally to caudal peduncle, straight along caudal peduncle to base of caudal-fin rays. Ventral profile of body similar to dorsal one. Dorsal-fin origin almost equidistant from tip of snout and base of caudal-fin rays. Anal-fin origin placed below posterior half of dorsal fin. Tip of pectoral fin surpassing pelvic-fin origin even in small specimens; in males, pectoral tip reaching half of pelvic fin. Tip of pelvic fin surpassing anal-fin origin in all males; in females, pelvic fin reaching or scarcely surpassing that point. Head with lower jaw as long as upper jaw. Premaxilla with short ascending process. Outer row of premaxillary teeth with 4 – 5, tricuspidate teeth, second or third tooth of outer row sometimes positioned out of line. Inner series with 5 teeth, symphysial tooth tetracuspidate, remaining teeth pentacuspidate to tricuspida

Redescription of Astyanax stenohalinus Messner, 1962 (Characiformes: Characidae), a poorly known species from Argentina and Uruguay

diagnosis

Emended diagnosis: Astyanax stenohalinus is distinguished from all other Astyanax species by the possession of hooks on all fins of males, teeth not expanded distally, two or three maxillary teeth, 37 – 39 perforated scales in lateral series, 25 – 30 branched anal fin rays, and anal-fin origin located before a vertical through last dorsal-fin ray insertions (Fig. 1).

Redescription of Astyanax stenohalinus Messner, 1962 (Characiformes: Characidae), a poorly known species from Argentina and Uruguay