Shiva Nedaei - Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran
Soheil Eagderi - Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran
Hadi Poorbagher - Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran

Fish body shape is an important morphological index in swimming behavior andhabitat selection. Hence, body shape not only reflects genetic traits of fishes but alsocan reveal environmental conditions. The objective of this study was to compare twopopulations of Capoeta capoeta from the Aras and Sefidrood Rivers in the CaspianSea basin using landmark-based geometric morphometric method. In total 60specimens were captured from the Sefidrood (30 specimens) and Aras (30 specimens)Rivers in the Caspian Sea basin using electrofishing and fixed into buffered 10 %formalin after anaesthetizing by clove solution. The left side of specimensphotographed using digital camera and 16 landmark-points were defined anddigitized on 2D pictures using TpsDig2. Non-shape data removed from obtained datausing GPA and analyzed using DFA and Ttest hoteling. Results showed significantdifferences between body shapes of two studied populations (P<0.0001). Thedifference were related to larger head and shorter caudal peduncle of the Sefidroofspecimens. This findings revealed ongoing evolutionary process in body shape ofseparated populations in various river of the Caspian Sea basin as result of habitatseparation.

Geometric morphometrics, Capoeta, Aras River, Sefidrood