Effects of Artificial Shelters on Survival Rates and Growth Performances of Scalloped Spiny Lobster, Panulirus homarus (Linnaeus, 1758), Reared in Floating-Net Cages

Cannibalism causes severe losses and has been considered one of the most important challenges in lobster aquaculture. The present study aimed to assess the effects of artificial shelters on the survival rate and growth performances of the scalloped spiny lobster, Panulirus homarus (Linnaeus, 1758). Wild-caught 600 puerulus stage scalloped spiny lobsters (~0.18 g wet-weight and 7.16 cm total length) were randomly allocated into floating cages provided with four different shelters; i) polyvinyl chloride (PVC), ii) nylon net, iii) cement sack and iv) no shelter as a control and cultured for 10 weeks to measure mortality and growth. The result of the experiment done in triplicate indicated that artificial shelters significantly affected scalloped spiny lobsters' survival rate and growth performances. The survival rate of scalloped spiny lobster in the control group observed on week 2 was only 62 %, while the survival rate in all treatments (with shelter) was 76 to 82 %. After 10 weeks culture period, the mean survival rate was only 28 % in control, which was significantly lower than all treatments (53 %, 54 %, and 59 % for nylon net, cement sack, and PVC, respectively). Similarly, the absolute growth and specific growth rate of the spiny lobsters reared with the artificial shelters were significantly better than that of lobsters in the control group. The best growth was obtained from lobster reared with a nylon net, followed by cement sack and PVC pipe. This research finding can be used to select suitable shelters for cultivating spiny lobsters.