Heterotrophic feeding of hermatypic corals in Luhuitou Sanya

The acquisition of energy and nutrients is the basis of sustaining the life activities of hermatypic corals, which mainly depends on the alimentation mode. Hermatypic corals are mixotrophic organisms, both autotrophic and heterotrophic. Photosynthesis by zooxanthellae is the basic form of autotrophy, but little is known about the heterotrophic feeding. To know more about it, three representative species in the Sanya Luhuitou Bay, Galaxea fascicularis, Pocillopora damicornis and Acropora muricata were selected in this study to test their feeding habits. Their feeding reaction to Artemia salina, copepod used in aquarium, yeast extract liquor and aquatic coral food were observed. What’s more, G. fascicularis’s feeding rate and digestion of A. salina were probed into. G. fascicularis ingests four kinds of food mentioned above, while A. muricata ingests none of them and P. damicornis only ingests A. salina and aquatic coral food. It’s reported for the first time that P. damicornis ingests A. salina by mesenterial filaments and it ingests aquatic coral food through the cooperation between polyps. Moreover, G. fascicularis’s feeding rate of A. salina and the density of A. salina nauplii well fitted into the Michaelis-Menten model. A. salina was completely digested by G. fascicularis in 3 h. The research can deepen our knowledge about the feeding of hermatypic corals, especially in the process of artificial coral breeding.