Morphological discrimination between two populations of shemaya, Chalcalburnus chalcoides (Actinopterygii, Cyprinidae), using a truss network

Abstract

Several body measurement methods used to identify stock have recently been criticized because of inherent biases and weaknesses. As an alternative, a new system of morphometric measurement called the truss network has been increasingly used for stock identification. We studied the morphometric differentiations between two populations and sexes of shemaya fishes (Chalcalburnus chalcoides) using a truss network. Truss distances between 15 landmarks of 66 specimens were measured. Size adjustment transformations were assessed by dividing characters (truss distances) by centroid size of specimen. Multivariate analysis of variance (MANOVA), principal component analysis and discrimination analysis were performed to investigate distinction and patterns of morphological va­riations between populations and sexes. The MANOVA (Wilks test) indicated a significant difference for mean vectors between populations (Λ = 0.136; F = 47.76; P = 0.001) and sexes (Λ = 0.120; F = 45.32; P < 0.001). Discrimination analysis correctly classified 97% and 89.4% samples to their original groups for population and sex, respectively. Our findings support the use of the truss network to study morphological variation among populations as it provides interesting perspectives for the study of biodiversity patterns.