Comparison of Transcaucasian Chub (Squalius turcicus De Filippi, 1865) popualtions in south-western Caspian Sea basin using geometric morphometric method

For geometric morphometric comparison of chub, Squalius turcicus,, in Ghezel-Ozan, Kasma, Palangabrud, Talvar, Tonekabon, Chalakrud, Divandareh, Zalkie, Zarinrud, Sefiedrud and Shafarud and Noor rivers of south-western Caspian Sea basin, 243 specimens were captured by a seine nets. After anesthetizing in 1% clove oil solution and fixing in 10% neutralzed formalin, specimens were transferred to the Isfahan University of Technology Ichthyology Museum (IUT-IM) for further studies. To study the variation of body shape based on geometric morphometric methods, 13 landmarks were defined on the two-dimensional images taken from the left side of samples using the TpsDig2 software. After Procrustes analysis (GPA), digitized data were analyzed using multivariate analyses such as principal component analysis (PCA), canonical correlation analysis (CVA) and cluster analysis, also, network deformation changing configuration patterns of population compared to form of the consensus by visualization. Results showed significant differences between the populations studied. The major differences in body shape of the studied populations were related to the head and body depth, and position of the pectoral, anal and dorsal fins. The observed changes are due to adaptation to the habitat, which has been influenced by different habitat conditions and has shown different body shapes.