Morphological variation in Leaping mullet populations, Chelon saliens (Risso, 1810) in the southern part of the Caspian Sea basin using geometric morphometric method

It is important to study and investigate exotic species to protect their stocks. This study was carried out to investigate the morphological change in Chelon saliens populations from southern basin of the Caspian Sea. For this purpose, during 2020-2021, by beach seine nets, 238 specimens were collected from seven costs including Astara (35 samples), Talash (45 samples), Bandar Anzali (50 samples), Kiashahr (33 samples), Langaroud (15 samples), Chaboksar (40 samples) and Sari (13 samples). After imaging the lateral view of the samples, some 14 landmark-points were defined and digitized on the two-dimensional images. The body shape data after generalized procraust analysis were exposed to statistical analysis including principal component analysis (PCA), canonical variate analysis (CVA) and cluster analysis (CA). Also, the deformation patterns of each population related to consensus shape of the populations in the deformation grids were illustrated. The results showed that there is a significant difference among the studied populations in terms of morphology. The highest Mahalanobis and Procraust distances were obtained in Langaroud and Sari, respectively. The main morphological differences were related to the position of the mouth, head size, body depth and caudal peduncle length, indicating the high morphological flexibility of this exotive species in adaptation with different habitats of the Caspian Sea basin.