Faunistic of fresh water crab in East River of Tehran province

During research in different seasons (winter and spring, summer and autumn), freshwater crabs in the eastern rivers of Tehran province (Jajroud, Hablehroud and Lar) in Fasham, Saeedabad, Khojir, Zarrin Dasht and Simindasht stations were carried out using hand net. They were evaluated in terms of carapace length and width, weight and body color. Finally, the results of this study showed that the species of crab found was Potamon persicum, which had a strong and positive correlation between carapace length, carapace width and also the weight of this crab in the samples found of Rivers (Jajrud and Hablehrood), stations (Fasham, Saeedabad, Khojir, Zarindasht and Simindasht) and gender did not affect the carapace length, carapace width and weight of this crab. In terms of average population distribution, P. persicum crabs were the same in Jajroud and Hableh Rud rivers as well as Fasham, Saeedabad, Khojir, Zarrin Dasht and Simin Dasht stations, but this average population distribution was significantly higher in summer and autumn than in winter and spring (p < 0.05). The population frequency of this crab was 70% in Jajroud river and 30% in Hablehrood; At Fasham, Saeedabad, Khojir, Zarrin Dasht and Simin Dasht stations, the frequencies were 32, 19, 18, 21 and 10% of the total samples, respectively. The results of body color also showed that the color of the carapace and legs were often dark brown and in some cases light brown.