Morphological variation of Catfish Glyptothorax galaxias populations in the headwaters of the Karun drainage basin watershed using traditional and geometric morphometric methods

In the present study, for the morphological comparison of Glyptothorax galaxias populations, 54 samples were caught from the four stations of Afsarabad, Armand, Bazoft and Beheshtabad from the headwaters of the Karun watershed. The geometric morphometric analysis was done based on 15, 13 and 10 homologous morphological landmarks on lateral, ventral and dorsal. Landmark method determined the out shape body and related analysis such as PCA, CVA, DFA, and dendogram was performed to show if there were differences among population of Glyptothorax galaxias. The results showed that the population living in Armand branch is separate from other populations, Bazoft and BeheshtAbad populations have the least distance and are placed in the same cluster, and Behesht-Abad and Afsarabad populations overlap with each other to some extent. It seems that the difference between different habitats in terms of flow intensity, river slope, nutritional conditions and water physics and chemistry is the reason for the difference in populations, which should be investigated in future studies. Considering that the species G. galaxias is native to the drainage basin of the Persian Gulf of Iran and the studies conducted on this species are very few and limited. Therefore, a comprehensive study of this species from different morphological aspects is necessary.