A study on habitat preferences of Tuini fish (Capoeta damascina) using the habitat suitability index in the Kordan River

The habitat is one of the most important factors in species conservation. Since conservational plans can be set using habitat characteristics that are used by endangered species. Accordingly, the present study aimed to investigate the habitat requirements of Capoeta damascina in the Kordan River. This rivers flow in central part of the Alborz province. Along the river, three sampling stations were determined (up-, mid- and downstream). Samples were collected from the summer and the winter. Three fish samples were collected from each sampling station using electrocution. Totally, nine samples were collected. Sampling points were roughly located at a 100-m distance from each other. Environmental parameters were recorded at each station including water velocity, depth, water temperature, pH, width of the river, sediment texture, and diameter of boulders and total organic matter of sediment. Suitability indices were calculatedwith a maximum score of 1 for each environmental parameter and their average was calculated as habitat suitability index. General additive model was used to find a relationship between environmental parameters and suitability indices. Results showed that the downstream area of the river (third station) was the most favorable habitat for C. damascina. The present study may be used to assess suitability of habitats using indicating species in freshwater streams.