Morphological discrimination in juveniles of two Selene Species (Teleostei: Carangidae) using truss net distances

摘要

External morphological distinction between young Selene vomer and S. brownii (Carangidae) was studied using multivariate analysis with the purpose to evaluate if other characters than the second dorsal and pelvic fin spines could be used as distinguishing attributes for juveniles fishes. These spines are important distinctive morphological characters, but they can be absent in juvenile fishes or be broken during manipulation. A sample of 389 specimens was collected from beach netting at Cai?ara do Norte (RN), northeastern Brazil, in 2001. Each specimen was digitalized and their images provided numerical matrices using Scion Image and FANTOMAS software. A C-language program was developed and used to calculate 16 Euclidean distances and nine homologous landmarks plotted on images. Discriminant analysis results revealed that the two Selene species was clearly distinguished employing morphometric procedures of diagonally oriented measurements of the antero-posterior body axis.