Fishery Biology and Population Structure of the Blue Swimmer Crab, Portunus pelagicus, from the Red Sea, Egypt

More than 300 MT of blue swimmer crabs (BSC), Portunus pelagicus, are annually captured from the fisheries Egyptian Red Sea waters. During last 20 years, a decline has been witnessed in production this species. For management purposes, information about fishery's biology and population structure is required. Hence, monthly samples P. pelagicus were collected commercial catch Hurghada landing site, Sea, Egypt during period November 2017 to October 2018. A number 1190 specimens measured for morphometric relationships, sex ratio, age determination using carapace width frequency, structure, mortality rate exploitation ratio. The study revealed that plagicus was targeted by trammel nets caught small bottom trawler as by-catch. Carapace width- total weight relationship showed positive allometric growth (b-value= 3.10). Higher condition factors observed individuals. Four groups determined group +I dominant (60.6%). Parameters von Bertalanffy equation 21.19 cm, 0.414 year-1, -0.998 year CW∞, K to, respectively. at first capture estimated (CW50 = 8.7 mm). rates calculated 2.929, 1.285 1.644 year-1 total, natural fishing mortalities, crab on over-exploited (E= 0.65) net. Some measures suggested maintain its stock sustainability.