Growth of Kappaphcus alvarezii in vertical method of multi-trophic system based on feeding rate

There is a need for knowledge to clarify the consistency of the complexity of feeding rates when applied to the multi-trophic aquaculture system. For this reason, three levels of feeding rates in rabbit fish as fed species were investigated to determine the growth performance of Kappaphycus alvarezii as nutrient absorber seaweed. Four plastic tanks were arranged in a graded position with a closed recirculation system, each for seaweed, rabbit fish, shells and sea urchins. Kappaphcus alvarezii was stocked vertically in the amount of three columns on four hanging ropes. Three levels of rabbit fish feeding rate were tested in this study, namely 5%, 7.5%, and 10% of fish wet weight with a frequency of four times a day. Every two hours after feeding, water was flowed into each tank for two hours. After 42 days of rearing, the results showed that growth performance of K. alvaresi varied among the three feeding rate levels. The average body weight gain (AWG), specific growth rate (SGR), daily body weight gain (DWG), and biomass of K. alvarezii in columns 1, 2, and 3 at the same feeding rate did not show significant differences (P>0.05). However, at different feeding rates, AWG, SGR, DWG, and biomass of K. alvarezii increased linearly and showed significant differences for each feeding rate (P<0.05). The implication of feeding rate does not seem to be a problem in multi-tropic system, at least up to the level of 10%. This study indicates that the 10% feeding rate is not optimal for the growth of K. alvarezii, so it is still possible to increase it to achieve higher growth of K. alvarezii.