The morphological study of transcaspian marinka (Schizothorax pelzami) in Harirud and Dasht-e Kavir basins using the geometric morphometric technique

This study was conducted to understand the morphological variation of four populations of Schizothorax pelzami from Iranian inland waters. For this purpose, a total of 81 specimens were collected from the Bidvaz, Cheshmeh-Ali, Kalat and Aal rivers. After anesthesia, all specimens were fixed into buffered formalin and transferred to the laboratory. Then, the left sides of all individuals were photographed. To extract the body shape data, 14 landmarks-points were defined and digitized on 2D image using TpsDig2 software. To eliminate size, direction and position from data, the Generalized Procrustes Analysis (GPA) was performed. Then, PCA, MANOVA/CVA and cluster analysis were used for further investigation. The results showed that there was no significant difference but some overlapping among the studied populations on the basis of PCA analysis was observed. The CVA graph separated the studied populations from on another. The main differences in body shape of the studied populations were related to the position of the snout, the depth of head and body, and the length of caudal peduncle. The observed changes can be considered to be an adaptation to their habitat, which has been influenced by different environmental parameters.