Journal of Aquaculture Research & Development

Abstract

Crablet of Mangrove Crab, Scylla olivacea Rearing at the Different Salinity Regimes

Gunarto and Andi Parenrengi

High canibalisms in crablet of mangrove crab, S. olivacea stage was resulted lower juvenile crab production. The objectives of the research is to know the efectiveness of crablet rearing at the different salinity regimes in floating plastic glass individually to minimize canibalism. Research was conducted at mud crab hatcheri Marana Station of RICA Maros. Day-7 crablet produced from a hatchery, and then reared individually in plastic glass provided with small holes in glass to enter water inside the glass. Crablet were stocked inside of the plastic glass individually, then it sets in a floating cage constructed with bamboo fenced, where a piece of styrofoam as they float in surface water in the aquarium. Nine aquariums each size 29×60×34.5 cm randomly was filled 30 L saline water with different salinity regimes, i. e. (A) 5 ppt, (B) 10 ppt, (C) 20 ppt, (D) 30 ppt. Each treatment in the three replications. Monitoring was conducted on growth increment (total weight and carapace width) and survival rate of crablet during one month rearing. Water quality monitored on dissolved oxygen, water temperature and alkalinity. Result of the research was showing that the highest growth increment of crablet was obtained in A treatment (0.74 ± 0.13 g) and significantly different (P<0.05) with D treatment, but there was not significantly different (P>0.05) with B (0.57 ± 0.10 g) and C treatment (0.61 ± 0.15 g). The carapace width was significantly different (P<0.05) between A and B, A and D, B and C, B and D, C and D. The highest of survival rate (100%) was obtained in C treatment and significant different
(P<0.05) with A treatment (73.3 ± 11.55%). However, there were not significantly different (P>0.05) with B and D treatment.