Investigation of morphological variation of Oxynoemacheilus elsae from rivers of the Urmia Lake basin using traditional and geometric morphometric methods

During 2018-2019, to study the morphological diversity of Oxynoemacheilus elsae, a total of 51 specimens were collected from the Godarchai, Barandozchai, Zarrinehrood and Mahabadchai rivers, Urmia Lake basin using electrofishing. From the collected samples, 22 morphometric characteristics were measured using a digital caliper with an accuracy of 0.1 mm. Also, in geometric morphometric (GM) method, the side of the samples were photographed, and 14 landmarks were digitized using tpsDig2 software. The extracted data were analyzed to understand morphological variation between the studied populations using multivariate analysis i.e. PCA, MANOCA /CVA and cluster analysis. The results showed a significant difference between the studied populations in terms of the morphological characters (P<0.05). In traditional method, there were significant differences in 10 traits between the studied populations (P<0.05). The main differences in GM method were related to the body and head depth, mouth position and caudal peduncle height. The observed morphological variations show the high adaptability of this species, especially in the pectoral fin length and body height traits with habitat adaptation.