Investigation the diet and digestive tract histology of loach fish Turcinoemacheilus bahaii in Zayandeh Roud River

Diets and digestive tract histology of loach fish Turcinoemacheilus bahaii (Nemacheilidae) were studied for the first time in Zayandeh Roud River (Isfahan basin). Fishes were cached seasonally by two layers gillnet in Deme basin through one year (2013-2014). On each sampling date, the macrobenthos were also taken by a surber sampler. The density of the macrobenthos was compared with the diet of loaches. The results were showed that the loach was feed on macrobenthos. Chironomidae and Baetidae composing %82 of total frequency were used as the most abundant prey by loach fish and showed overlapping with the results of abundant of macrobenthos communities. The average of RLG (0.46±0.04) also confirms that the species was classified as carnivore. The digestive tract in the species was included the esophagus, stomach and intestine and the histological characteristics revealed that the wall of digestive tract is composed of the tunica mucosa, submucosa, muscularis and serosa. The tunica mucosa had simple columnar cellsthat in associated with goblet cells in intestin.