Different groups of decapods crustacean exist in the Persian Gulf and Oman Sea which are caught during shrimp fishery season. Portunid crabs, especially Portonus segnis, are the most commercially important of all true crabs in coastal waters of Hormozgan province. In earlier studies, the blue swimming crab in the northern Persian Gulf was incorrectly identified as Portunus pelagicus (Kamrani et al., 2010). Further investigations by Lai et al. (2010) showed that Portunus segnis is confined to the western Indian Ocean from Pakistan to South Africa. The results of present study mirrored the result by Lai