Analysis habitat range of Safidrud stone loach (Oxynoemacheilus bergianus) in Kordan River (Namak Basin, Alborz Province), in autumn

Based on the fact that there is little information about natural habitat of the native loach Oxynoemacheilus bergianus, this study was conducted to analyze the habitat range and the preferred habitat of the Safidrud stone loach in Kordan River in the autum 2012. For this purpose, the variables including water depth, river width and slope, altitude, water flow rate and debit, substrate material, over-stream canopy closure, and riparian vegetation type, along with the relative abundance of the interested fish species were analyzed in 66 stations along the river. Based on the results, the habitat use by this species in Koradan River was in altitudes of 1300-1500 meters above sea level, widths of 5-15 m, slopes of 0-49 m/km slope, depths of 6-42 cm, and flow rate of 0.3-1.2 m/s. The highest value of the standardized habitat selectivity indices for Safidrud stone loach in Kordan River were related to the altitudes of 1400-1500 m, widths of 10-12.5 m, slopes of 14-21 m/km, depths of 17-24 cm, and flow rates of 1.1-1.2 m/s. In addition, in the habitats selected, the substrate was gravely, banks had little riparian vegetation cover, and little over-stream canopy closure.