Inter-species mating among mud crab genus Scylla in captivity

Abstract

Mud crab genus Scylla is one of the economically important crustacean species with high market value worldwide. With the report of natural hybrid mud crab being found in Japan, this study investigates the feasibility of inter-species mating within the genus Scylla (Scylla olivacea, Scylla tranquebarica and Scylla paramamosain), and the effect of choices (mating partners of different species) and originating locations (Perak, Terengganu, Sabah and Sarawak) on mating success. Our study shows that mating among all three Scylla species is inducible in captivity. When choice of partner was absent, the effect of originating location of mud crabs was negligible. Males of S. olivacea was the most versatile and readily mate with females of other species with a mating success rate as high as that of pure species when choice of own species was not presented. Duration of different mating phases did not differ significantly between crosses, except precopulation phase. With the presence of choices, S. olivacea and S. tranquebarica from all locations preferred each other compared to S. paramamosain. S. paramamosain however, showed significant variation in inter-species mating success, with those from Sabah and Sarawak having higher success rate than those from Perak and Terengganu. The results of current study can be used to spearhead the production of first mud crab hybrids and open up countless possibilities in the aquaculture sector.