Comparative geometric morphometric study of Capoeta fusca populations in Kavir and Harirud basins

Abstract
Quantifying morphological characteristics of body shape in fishes can help their correct identification as well as understanding of evolutionary history of their different populations. Hence, this study was aimed to compare the morphological characteristics of different population of siahmahi (Capoeta fusca) in inland-water of Iran using geometric morphometric method (GM). In total 122 specimens of Capoeta fusca were collected from three rivers Amirabad, Kalshur, Tabarak. Then, the lateral surface of their left side photographed and seventeen landmark-points defined and digitized using TpsDig2 software to extract body shape data in geometric morphometry. The coordinate data after GPA superimposing, analyzed using principal component analysis (PCA), canonical variate analysis (CVA) and cluster analysis (CA) and body shape pattern of every population was visualized in relation to consensus shape of total populations. Based on the PCA, six factors were above the Joliff line and accounted for more than 79.37% of the variance. The highest variances were related to the head size, body depth, dorsal and anal fin position, dorsal fin base length and caudal peduncle length. The CVA and PCA morphometric of Capoeta fusca indicated that the three populations of Kalshur, Amirabad and Tabarak have meaningful differences and they are separated from each other (p<0.0001). The cluster analysis has also isolated the population of Kalshur from the populations of Amirabad and Tabarak.