Investigation of the habitat preference of sympatric species, (Oxynemachilus kiabii) and (Oxynoemacheilus karunensis) from Alk River (Karkheh River basin)
Document Type : Research Paper
Authors
1 Department of Fisheries Sciences, Faculty of Natural Resources, University of Kurdistan, Sanandaj, Iran
2 Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran
3 Department of fisheries, Faculty of Natural resources, University of Kurdistan
Abstract
Models based on regression analyzes are used to express patterns of abundance and distribution of fish populations in relation to environmental parameters. Therefore, this study was conducted to investigate the habitat suitability indices of (Oxynemachilus kiabii) and (O. karunensis) from Alk River (sub-basin of Razavar and Karkheh basin). Sampling was done using a hand net in eight stations (each with three replicates). Five habitat variables were measured and recorded, including river width, river depth, bed slope, water velocity, and average bed size. The results showed that the most habitat preference of Kiabi loach is depth in the range of 46-<52 cm, 0.6-<0.9 m width, 5.8-<6.4% slope, and water velocity 0.52-<0.58 m/s and the size of bedrock is 0-<0.12 mm and for (O. karunensis) was calculated as depth in the range of 10-<16 cm, 2.1-<2.4 m width, 1.6-<2.2% slope, and water velocity 0.34-<4 m/s and the size of bedrock is 48-<60 mm. Also, the highest and lowest SI values for both (O. kiabii) and (O. karunensis) were related to depth and average bed size (for O. kiabii) and velocity and depth (for O. karunensis), respectively. The results showed that Alk River is a suitable habitat for (O. karunensis), whereas not suitable habitat for (O. kiabii). Examination of the results of their feeding habits and preferences in the digestive system showed that these favorite of fishes are Chironomidae, Simulidae, Baetidae, Gomphidae and Hydropsychidae.
Keywords
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