The Preference Size Of Male Mud Crab, Scylla tranquebarica at Success Mating With Female , Scylla olivacea in Controlled Tanks

Interspecific hybridization of mud crab Scylla spp has been successfully conducted in controlled tanks. However, there is no information yet available about the male size S. tranquebarica is capable to copulate with female of S. olivacea . The objectives of the experiment is to find out the male size of S. tranquebarica that willingly copulated with newly molted female of S. olivacea . Twelve individual of adolescent female of S. olivacea were reared individually in the conical fibreglass tanks each of 400 L volume. In another tank, 12 adult male S. tranquebarica with various size (200-400g/ind.) were also prepared. The crabs fed with chopped trash fish in the morning (7.00 am) and afternoon (17.00 pm) at 5% of the total crab biomass. Each newly molted female is transfered to the copulation tank and three male of different size also stocked at the copulation tank, then wait until one of the three male do copulation with female new molt. The size of copulated crabs (body weight, carapace with, and carapace length) were recorded. The female crabs sizes were measured before and after molting, whereas, the male crab sizes were measured soon after mating process has finished. Post mating, the female crab then reared individually in the tank until spawned. The result showed that male S.tranquebarica of >300g individual weight are preferable to copulate with female S. olivacea, and contrary none of male crab with size