Morphological variation of Oxynoemacheilus bergianus (Derzhavin, 1934) from the Namak Lake and Caspian Sea basins using traditional morphometric method

In this study, the morphological variation of Oxynoemacheilus bergianus was studied in the different rivers of the Namak Lake and Caspian Sea basins using traditional morphometric method. For this purpose, a total of 76 specimens were collected from eight river systems and after fixation into 4% buffered formalin, transfered to the laboratory, a total of 31 morphological characteristics were measured using digital calipers. After standardization, the morphometric data were analyzed using multivariate analysis including principal component analysis (PCA), canonical variate analysis with p-value obtained from MANOVA (MANOVA/CVA) and cluster analysis (CA). The results showed significant differences in 24 traits between the studied populations (P<0.05), which anal fin depth and the ventral-anal fin distances were main discriminative ones. CVA analysis was able to separate the studied populations. Also, CA placed the Gharesu and Sefid populations in a clade and separate from other populations. The observed differences may be related to phenotype plasticity in response to environmental conditions.