Population dynamics and reproductive aspects of the Ghost crab Ocypoda saratan at Jeddah
coast, Saudi Arabia

Al-Solamy, M.A¹ and Hussein H.K^{1, 2}

¹Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia

²Department of Zoology, Faculty of Science, Alexandria University, Alexandria

*Corresponding  Author  E-mail: ahssan555@yahoo.com

Accepted 07 July, 2012

The population dynamics and reproductive aspects of the ghost crab, Ocypoda saratan were studied in Jeddah, Saudi Arabia. Crabs were randomly sampled on monthly basis during low tide periods from January to December 2011 at costal shores of Jeddah province. A total of 82 crabs was obtained, of which 37 (45.1%) were males, 24 non-ovigerous females (29.3%) and 21 (25.6%) ovigerous females, respectively. The present population presents non-normal size frequency distributions, with males reaching greater size than females. The overall sex ratio (M:F) (1:0.84) was significantly different from the 1:1 ratio. Ovigerous females were present throughout the year and the embryonic development showed synchrony with the gonadosomatic index, in which females carrying eggs close to hatching were more abundant when the gonadosomatic index reached minimum values in the population. Egg number increases with female size. Juvenile recruitment was also continuous with high proportion of young recruits being recorded in winter, probably due to the high reproductive activity displayed in summer. Ocypoda saratan exhibits a rapid embryonic cycle accompanied by a rapid larval development and settlement in the study area.

Keywords: Ghost crabs; Population dynamics; Sex ratio; Juvenile recruitment; Ocypoda saratan.