Application of multifactorial discriminant analysis in the morphostructural differentiation of wild and cultured populations of Vieja Azul (Andinoacara rivulatus)

To better determine the ecological variation (body shape and structure) of the Vieja Azul (Andinoacara rivulatus; syn.: Aequidens rivulatus) in northwest Ecuador (Los Ríos Province), 300 specimens of both sexes (150 male and 150 female) were collected from 3 different locations, one from a wild production system and two from fish farm populations in the Quevedo River. Twelve meristic, 26 traditional morphometric, and 32 truss measurements, among 25 anatomical landmarks, were determined. The body weight (BW), total length (TL), eye diameter (ED), dorsal fin ray length (DFRL), and body perimeter 3 (P3) showed significant differences (P < 0.05) between production systems, and sex had significant influence on preanal length (Pre-AL), P3, and body width 2 (LC2).