GROWTH PERFORMANCE OF SPINY LOBSTER Panulirus ornatus SEA CUCUMBER Holothuria scabra AND SEAWEED Kappaphycus alvarezii IN INTEGRATED MULTI-TROPHIC AQUACULTURE SYSTEM

Interest in development of lobster culture has grown significantly to meet the market demand. As with other species, this expansion of lobster culture has caused deterioration in water quality mainly because of the waste produce by the lobster and uneaten feed. Integrated Multi-Trophic Aquaculture (IMTA) offers a combination of different aquaculture species wherein waste, from one species turn into nourishment or fertilizer for another species. This study was conducted to determine the suitable diet for spiny lobster as well as the growth performance of sea cucumber and seaweed integrated in an IMTA system.

Spiny lobster (Panulirus ornatus), sea cucumber (Holothuria scabra) and seaweed (Kappaphycus alvarezii) were selected. The IMTA system consisted of (1 m × 0.5 m × 1 m) 500L tank for spiny lobster and two (1.3 m × 0.8 m × 0.4 m) 500L tanks, one for sea cucumber and other one for seaweed cultivation. The stocking rate was 5 ind/tank both for spiny lobster ( mean BW 325.61 ± 14.32 g) and sea cucumber ( mean BW 56.43 ± 2.33 g) while initial biomass of seaweed was 504.84 ± 0.59 g/tank. Spiny lobster was fed with three different diets, trash fish (Diet 1), mangrove clam (Diet 2) and commercial shrimp pellet (Diet 3) for 12 weeks. The feeding frequency was two time in a day (8:00h and 16:00h). In situ water parameters were recorded daily and sediment samples were collected at two weeks interval.

The specific growth rate of 0.15 ± 0.06 %/day in spiny lobster was significantly higher (P<0.05), when fed with Diet 1 compared to specific growth rate (0.12 ± 0.04 %/day) obtained with Diet 2 and Diet 3. The survival rate of 73.33 % was observed in spiny lobster fed with Diet 1 but it was lower (66.67 %) when lobster was fed with diets 2 and 3. Sea cucumber performance was poor in this trial. There was no significance difference (P>0.05) in specific growth rate of the seaweed among the three dietary treatments. The results indicated that waste generated from spiny lobster tank may not be sufficient for supporting growth of Holothuria scabra or may not be efficient to extract organic matter but Kappaphycus alvarezii indicated the assimilation of inorganic nutrients in this system. The results are interesting not only in terms of production efficiency but also environment-friendly method of farming that the IMTA system designed for this study has offered.