By Tamra Werner MS, MM Children's Marine Life Author Coral Reefs have hundreds to thousands of living organisms and live in symbiosis. The life cycle of the coral is a complex food web of nutrients recycled in symbiotic relationships. Coral grow their food with organisms like fungi, algae, and bacteria in the coral body. The algae produce sugar that the corals eat, causing the release of CO2 necessary to harvest more sugar. The growing coral then supports other reef organisms