Pemeliharaan Zoea-5 dan Megalopa Kepiting Bakau, Scylla olivacea dengan Wadah Berbeda
The different kind of tanks used for culture of zoea-5 and megalops of mangrove crab, S. olivacea may impact to the degree of stability of an environmental factors mainly water temperature which will influences to the acceleration of zoea-5 and megalops develop to the crablet. The objectives of the study is to find out the suitable of tank condition for culture of zoea-5 and megalops which indicated by the fast develop of zoea-5 and megalops to the crablet and the highest survival rate of crablet. Research was conducted in mangrove crab hatchery located in Marana Research Station of Research Institute for Coastal Aquaculture, Maros. Healty larval zoea-1 from the same broodstock reared in one unit circular fiberglass tank volume 4 ton was filled 3 ton sterile pond water salinity 30 ppt. Larval stocked at the density 100 ind./L. Circular aeration was made to prevent larvae accumulated in the tank bottom. Enrich rotifer, Brachionus plicatilis with HUFA (5 mg/L for two hours) as feed for larvae z-1 to Z-3 was given at the density 8-10 ind./mL. Enrich artemia nauplii with HUFA (50mg/L for two hours) as feed for larvae Z-3 to crablet stage was given at the density 1-2 ind./mL. The lowering of larvae stocking density was conducted after larvae reach zoea-5 and megalops stage. Three different kinds of tanks used for culture the combination of zoea-5 and megalops of S. olivacea, there were ie, A). Circular fiberglass tank volume 4 ton was filled 3 ton of sterilized brackishwater, aerated in circulation system and the tanks were placed in closed room, B). Rectangular cement tank volume 4 ton was filled 3 ton of sterilized brackishwater, aerated in circulation system and the tank was 90% closed with plastic line in surface part, C). Circular cement tank volume 4 ton was filled 3 ton filtered brackishwater, aerated in circulation system and the tank without closed in the surface part. These tanks were stoked with zoea-5 and megalops at approximately 5000 ind (A), 1500 ind (B) and 1360 ind (C). Each treatments in two replications. Naupli artemia at the density 1-2 ind./mL enriched with HUFA at 50 mg/L for 2 hours was given to the zoea-5 and megalops as feed. Monitoring conducted on the time that required megalops develop to the first instar of crablet, percentages of crablet survival rate in each kind of tank condition, water temperature, nitrit, amonium, total organic matter and total Vibrio sp. Result of the research showed that at the day 5-6 some megalops have developed to the first instar crablet and the total number was highest in A tank compared than those of B and C tanks. The high and stabil water temperature in the range of 30-32oC in A tank, may was most important factor that is influenced to the accelerated megalops develop to the first instar crablet. While in B tank, water temperature at the range of 30-31oC and C tank at the range of 27-30oC. Crablet D-7 was harvested and showed that the highest survival rate of crablet was obtained in A tanks (40,14 + 0,424%) then followed by C tank (34,65 + 11,101%) and the lowest was B tank (22,675 + 0,954%).