Species composition and biological imformation of mud crab, genus Scylla from Johor coastal water of South China Sea

Abstract

This study was conducted at Tg.Sedili, Johor Coastal Water area of South China Sea. The objectives of this study is to determine species composition and to obtain biological information which included carapace width (CW) - body weight (BW) relationship, size distribution and sex ratio of mud crab, genus Scylla. Randomly, 1126 mud crab genus Scylla samples from various species, size range and sex was measured and weight in July and December 2010. The study shows that the mud crab species composition was dominated by S. tranquebarica by 36.68%, followed by S. olivacea at 36.59% and S. paramamosain at 26.73% and no S. serrata were sampled. The male crabs are significantly bigger and heavier than female mud crab for all species. The rate of increase in body weight for S. olivacea is more than two other species which are S. tranquebarica and S. paramamosain. The size range for S. olivacea is 9-9.9 cm, S. tranquebarica is 10-10.9 cm and S. paramamosain is 11-11.9 cm. The male mud crabs are relatively more abundant than female for S. olivacea and S. tranquebarica. However, for S. paramamosain, the female mud crab is more abundant than male.