Food habits of Capoeta trutta Heckel, 1843, in Sezar River from Tigris catchment in Lorestan province

This study was conducted to investigate the feeding habits of Copeotatrutta in Sezar River from Tigris basin (Lorestan Province). Sampling was performed monthly from July to December 2011 using seine net with different mesh size and gill net with 50 mm mesh size. For diet analysis, a total of 79 C. trutta was sampled and studied. The mean RLG index was 9.97±0.24 showing herbivores feeding in C. trutta. The mean condition factor (K), index of fullness (IF) and vacuity index (CV) were 1.44± 0.01, 1.41± 0.01, 478.08±25.26 and 1.26, respectively. All feeding items were priphyton unicellular algae. In identified feeding items, the genera Navicula, Cymbella, Diatoma and Nitzschia were identified as the main food, the genera Fragillaria, Microspora, Pinnularia, Gomphonema, Oscillatoria, Pediastrum, Rhoicosphenia, Acnanthidium, Tribonema, Melosira, Surirella, Achnanthes, Lyngbya, Scenedesmus as the supplementary food and the genera Ulothrix, Gyrosigma, Spirogyra and Closterium as the incidental food of C. trutta. The main, supplementary and incidental foods were identified. Dietary indices showed good feeding condition of this species in Sezar River.