<b>Data for s</b><b>easonal variations in coral lipids and their significance for energy maintenance in the </b><b>South China Sea</b>

In recent years, the intensification of global warming and extreme climate have led to an increase in the frequency and severity of coral bleaching. Coral bleaching means a decrease in symbiotic zooxanthellae density (ZD). The decrease of ZD is usually accompanied by a reduction in the photosynthetic intensity of the zooxanthellae. This means that coral's material and energy obtained through the autotrophic photosynthesis will decrease, which in turn affects the energy supply for their growth and daily physiological metabolism. Previous studies have proven that coral can maintain stable energy supply by increasing heterotrophic feeding when the autotrophic photosynthesis decreases. Coral lipids contain components such as triglycerides and wax esters, are potential alternative energy sources. However, the mechanism of lipid energy supplementation during ZD reduction is still unclear. There were few studies on the seasonal changes of coral lipid contents and its mechanism for energy supply. Based on the δ13C labeling technology, we explored the coupling between lipids and ZD, zooxanthellae autotrophic photosynthesis, and host heterotrophic predation. The results show that ZD and the zooxanthellae photosynthesis intensity decreased in summer. Correspondingly,the content and δ13C of lipids are decreased significantly. This means thatstorage lipids containing heavier carbon isotopes are consumed. Corals can maintain the stability of energy supply by consuming their own stored lipids when autotrophic photosynthesis decreases. This energy maintenance mechanism has been rarely mentioned in previous research, which is important for improving coral’s adaptability to the environmental stresses as well as resistance to bleaching.