Habitat suitability index of Kermanshah stone loach (Sasanidus kermanshahensis Bănărescu and Nalbant, 1966) in Dinor River, a tributary of Gamasiab River

Dinor River is one of the tributaries leading to Gamasiab River in Tigris river drainage and one of the habitat of Kermanshah stone loach (Sasanidus kermanshahensis). The river has been affected by human activities such as agriculture. In this study, a total of 168 specimens were collected from 21 stations of Dinor River for the study of Kermanshah stone loach’s habitat suability index. For this purpose, the river characteristics, including water velocity (m/s), water depth (cm), altitude (m), river width (m), bedrock index, and average bedrock diameter (cm) were recorded at each station. The habitat suitability index was examined according to the relationship between environmental variables and species abundance. The results showed that river width and water velocity are directly related and altitude, water depth, and bed index were inversely related to the abundance of S. kermanshahensis. The HSI index with a value of 0.497 showed that this river has moderate suitability for this species. Also, the results indicated that the selected habitat of S. kermanshahensis includes areas with high water velocity due to the need for adequate oxygen, sand-mud bed, high width, low altitude, and shallow depth. The findings can be used to manage and protect the reserves of this species, which is part of the country's natural heritage..