GROWTH PERFORMANCES OF MUD CRAB Scylla olivacea FED ARTIFICIAL DIET AT DIFFERENT FEEDING RATES DURING NURSERY
Appropriated feeding rate applied during nursey of mud crab crablet is important because of high cannibalism crablet occurred at this stage. Feeding rates for crablet during nursey is still limited available in particular those use artificial feed. This study aimed to evaluate the growth and survival rate of mud crab crablet fed artificial feed at different rates during the nursery. Crablet with average initial weight of 0.038 g and initial carapace width of 3.25 mm aged 3-5 days post-crablet. The crablets were stocked in nine tanks of 1.0x1.0x0.5 m3, with density of 50 crablets / tank. Three daily feeding rates were tested at 20%, 30%, and 40% of the biomass and fed twice in the morning and afternoon for 5 weeks.
The results indicated that for the first 2 weeks, feeding rate of 20% had a lower survival rate (P<0.05) than the feeding rate of 30% and 40%. However, at the end of the feeding trial, the survival rate, growth rate, feed conversion ratio, feed efficiency and protein efficiency ratio were not significantly different (P > 0.05) among the treatments. It is recommended that at the first two weeks, feeding rate of 30% could be given to the crablet until they reach 0.2-0.3 g with carapace width around 8-10 mm, and then reduce it 5% in every week during the nursery.