Settlement and Metamorphosis of Coral Planulae Incubated withCommercial Peptide Hym-248 at Different Age

The success of coral planulae rearing needs stimulant for planulae to attach onto substrate. Commercial neuropeptide Hym-248 is known to induce planulae to metamorphose and settle. The timing to add peptide affects planulae attachment and metamorphosis. This research was aimed to describe the difference of settlement and metamorphosis in coral planulae added Hym-248 at the age of 1 day and 6 days. This research used a slick, egg-spem bundles released from multi-specific spawning corals. The study conducted at Sambangan Island, Karimunjawa Islands. Planulae were added with Hym-248 at concentration of 1×10^-7 M and 1×10^-5 M for 6 days old planulae and 1×10^-7 M, 1×10^-6 M, and 1×10^-5 M for 1 day old planulae. The highest settlement rate was observed on the planulae treated with 1×10^-6 M dose of Hym-248 at 144th hour with percentage of settled planulae was 32.08%. However, only 5.83% were metamorphosed after 60 hrs observation. One day old planulae incubated with Hym-248 started to attach at 4th hour and metamorphosed at 120th hour, whereas none of 6 days planulae attach or metamorphose until the end of the experiment. This study suggested that incubated planulae in Hym-248 media will give a better result when planulae are at one day old. This study highlight the possibility to produce mass-seedling colonies using sexually derived planulae.