Species diversity of fish in the Sanandaj Azad Dam ecosystem

Fish sampling was conducted to evaluate the species diversity of fish in 4 stations in Sanandaj Azad dam ecosystem seasonally from summer of 2017 to spring of 2018. A total of 1057 fish were caught in 12 species, of which more than 80% were caught in the lake behind the dam. The Cyprinidae family had 11 species with the most species diversity and only Sasanidus kermanshahensis belonged to the Noemachilidae family. There was no significant difference between Shannon species diversity in the lake behind the dam (with a mean of 1.11 ± 0.32) and Komaci River (P> 0.05), and in summer with other seasons there was a significant difference (P <0.05). The size and weight of the population living in the lake habitat behind the dam were significantly higher than the population living in the river habitat (P <0.05). Among the identified fish species, 5 species Carrasius auratus, Cyprinus carpio, Hemiculter leucisculus, Hypophthalmicthys molitrix and Pseudorasbora parva are exotic species. Among the influences of exotic fish is its competition with native fish for food, and this will have a significant impact on the species diversity of the fish, population dynamics and fish populations. Also Sasanidus kermanshahensis is an endemic species for Iran, which is very important for protection. Considering the importance of endemic species and the presence of a considerable number of exotic fish species in the Azad dam ecosystem, the results of this study are of considerable importance.