محمود نفیسی بهابادی

Diet and natural nutrition indexes of Cyprinion tenuiradius carp in Qara Aghaj Basin in Fars province were studied. Thirty-nine samples of Gharaaghaji carp, from October to January 2017 were caught from Ghareaghaj river by gillnet and castnet. The samples were fixed in 4% formalin and transferred to the laboratory and examined after basic biometrics. These specimens were in the range of 4.4 to 14.0 cm long, and weights ranging from 0.93 to 25.00 grams. After measurements, the fish was cut off by a scissor and a surgical scalpel along the midline of the abdomen from a few millimeters to the lower area between the gill caps and the digestive tract isolated from the esophagus to the throat. Then weigh the fish off, then the intestine is separated and the length of the intestine and the intestine weight with the contents are calculated. The contents of the stomach were then removed and fixed in 70% ethanol. The intestinal contents were diluted in 100 cc beakers and examined on glass slides for counting. Food materials were identified and classified under a microscope, and the microalgae content were identified using identification keys. Subsequently, the nutritional indices were calculated. The gastrosomatic index (GSI) was 23.64 ± 0.34 (mean ± Se) indicating good nutrition of fish. The condition factor index (K) was 1.07 ± 0.02 (mean ± Se) good biological status of the fish. The intensity of nutrition index (IF) is 1399.70 ± 66.49 (mean ± Se) which indicates good nutrition of the fish and vacuity index (CV) of 7.96 , indicating that this fish eats considerable amount of food. The relative length of the intestine (RLG) is 4.40 ± 0.080 (mean ± Se) which determines the phytophagousity of the fish. The genera Gomphonenema, pinnularia, Diatoma, Cymbella, Navicula and Cosmarium were the main food, and Pediastrum, Spirogyra, Nitzschia, Caloneis, Cymatopleura were identified as incidental foods. Analysis showed that the this species has a diet of phytoplanktivorous herbivore d