Body shape variation of Kura barb (Barbus spp.) in Iranian basins

The objective of this study was to determine the body shape variation among Kura barb species (Barbus spp.) in the Caspian Sea, Urmia and Tigris basins using landmark-based geometric morphometrics. For this purpose, a total of 128 specimens were sampled from the three basins using seine, gill and cast nets. The left side of each specimen was photographed using digital camera and 14 Landmark points were digitized on two-dimensional images using TpsDig2. Landmark data after a Generalized Procrustes were analyzed using Principal Component Analysis (PCA) and Canonical Variate Analysis (CVA) and the patterns of body shape differences among the studied population were illustrated in deformation grids in relation to consensus configuration of all specimens. The Principal Component Analysis could not differentiate the populations, but CVA displayed some differences among the populations. Habitat-associated morphological divergence, phenotypic plasticity and evolutionary process of body shape change among various populations and also, a relationship between the geographical distance and the degree of morphological divergence among populations in response to environmental factors in their habitat were observed. Thus, each population should be considered as separate genetic and morphological stocks.