Geometric morphology of Iranian Goby Ponticola iranicus Vasil'eva, Mousavi-Sabet & Vasil'ev, 2015 in the Southern Caspian Sea basin

The present study was conducted to determine the body shape variation among the populations of Iranian goby (P. Iranicus) in the southern Caspian Sea basin using landmark-based geometric morphometrics. A total of 350 specimens of the species were sampled using electro-shocker, and in the laboratory, the left sides of the fish samples were photographed by a digital camera. Fourteen landmark points were digitized on two-dimensional images using TPSDige2 software. The obtained data from Landmarks were analyzed using multivariate statistical analyses including PCA, CVA, and cluster analysis (CA). The phenotype plasticity patterns of each population related to the shape of the overall average of populations were illustrated. The results of the study demonstrated that there was a significant difference among the studied populations in terms of morphological features. Dendrograms revealed that both sexes could be divided into five groups related to the localities of specimens. Analysis of MANOVA/CVA showed that females of P. Iranicus have a high separation rate among the provinces, while males of Mazanderan province had significant isolation from males of Guilan and Golestan provinces. The two provinces showed a high overlap in the morphological characteristics. The results of the study can improve understanding of growing phenotype patterns plasticity of these fishes in the water bodies of different river systems from the southern basin of the Caspian Sea as well as identifying species of P. Iranicus populations in the southern basin of the Caspian Sea rivers.