Morphological flexibility of Transcaucasian Chub (Squalius turcicus De Filippi, 1865) in South-eastern Caspian Sea basin using geometric morphometric

In 2010-2011 in order to evaluate differences in body shape among populations of chub, Squalius turcicus, De Filippi, 1865 from Tajan, Haraz, Nekarud, Babolrud and Noor rivers of south-eastern Caspian Sea basin 264 specimens were captured by a seine nets. After anesthetizing the samples in 1% clove oil solution and fixing in 10% neutralized formalin, they 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 variation analysis (CVA) and cluster analysis, also, network deformation changing configuration patterns of population compared to form of the consensus by visualization. The results of this study showed that Babolrud and Haraz populations grouped apart from other populations. Also that the major differences in body shape of the studied populations were related to the head and body depth, and position of the pectoral and anal fins.