Assessment of habitat suitability of Oxynemachilus kiabii (Golzarianpour, Abdoli & Freyhof, 2011) in the Dinor River, Kermanshah province, Iran

The habitat suitability model is a common method for assessing the habitat needs of fish in freshwater systems. The aim of this study was to investigate the habitat suitability of Kiabi loach (Oxynemachilus kiabii) in the Dinor River, Kermanshah province, Iran. For this purpose, 7 stations along the Dinor River were sampled in April 2017 using an electrofishing device. In addition to recording fish abundance, environmental characteristics including water temperature, water velocity (m/s), depth (cm), river width (m), average bedrock diameter (cm), alkalinity (pH), electrical conductivity (EC), and total dissolved solids (TDS) was recorded at each station. The habitat suitability index was evaluated according to the relationship between environmental variables and fish abundance. Based on the results, the most desirable habitats for O. kiabii in the Dinor river are areas with a river width of 6-7.2 m, river depth of 26-34 cm, water flow velocity of 0.17-0.45 m/s, water temperature of 22-23 °C, EC values of 300-350 μS/cm, pH values of 7.80-8.92, TDS values of 580-610 mg/l, and average diameter of bedrock less than 5-6 cm. In the present study, the value of habitat suitability index (HSI) for O. kiabii was determined to be 0.51. Overall, the results showed that the Dinor River, in terms of habitat characteristics, compared to other fish species (such as Alburnus sellal), has a moderate suitability for the Kiabi loach. This indicates that the expansion of human activities in the Dinor River basin has disrupted the habitat range of this endemic species. Therefore, conservation priorities need to be considered by fisheries experts and managers in order to conserve and manage the stocks of this valuable species.