Dietary ecology of the Portunus segnis (Forskal, 1775) in the coastal waters of Hormozgan Province, Iran

Document Type: Research Paper

Authors

1 Department of Marine Biology, Faculty of Biological Science, ShahidBeheshti University, Tehran, Iran

2 Fisheries Department, Hormozgan University, Bandar Abbas, P.O.Box:3995, IR Iran

Abstract

 In this study, the feeding habits of  blue swimming crab  (Portunus segnis) from Hormozgan province (south of Iran) were investigated. A total of 722 specimens were collected using bottom trawl from June 2011 to May 2012. The samples were transferred to the laboratory in order to further analysis after freezing. At first, the biometry features such as body weight (BW) and carapace width (CW) were measured and then all individuals were dissected and their stomach was removed. The results showed that the vacancy index of stomach (CV) was 34.5 during sampling. This finding indicated that this species is a gluttonous crab. Also the analysis of its feeding habits showed that this species is carnivorous. The principal food items included crustacean, fish and mollusks. Diet varied seasonally. Crustaceans were more important in summer whereas fish and mollusks were more important during autumn and winter, respectively. The crustacean included shrimp and crab. The dominant mollusks were the bivalves such as Marcina hiantina, Circentia callipyga, Tellina sp., Cardita bicolor and gastropods Cerithium erythraeonese, Atys sp. There was significant difference in the frequency of occurrence of food items among sexes.

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