Principal Component Analysis (PCA) of morphometric data of A. colchicus, A. astacus, P. pachypus, P. leptodactylus. (A) Biplot of the variable PCA is shown based on the morphometric data of four different species (B) Biplot of the individual PCA is shown based on the morphometric data of four different species (C) Relative contribution of morphometric variables to Dim-1 and Dim-2 to discriminate four species.