Corals get their food from algae living in their tissues or by capturing and digesting prey. Most reef-building corals have a unique partnership with tiny algae called zooxanthellae. The algae live within the coral polyps, using sunlight to make sugar for energy.
How do they catch prey when they cannot move?
Corals also eat by catching tiny floating animals called zooplankton. At night, coral polyps come out of their skeletons to feed, stretching their long, stinging tentacles to capture critters that are floating by. Prey are pulled into the polyps’ mouths and digested in their stomachs.