Zooxanthellae and Corals

Corals are colonies of tiny animals that live in warm, shallow waters. Over thousands of years, coral colonies grow and form coral reefs. However, the animals cannot do this alone. They need the help of zooxanthellae.

Zooxanthellae are single-celled algae that live in the coral’s tissues. They give corals their beautiful colors and, more importantly, most of their food. Algae like zooxanthellae undergo a process called photosynthesis, which means they use energy from sunlight to make their own food. Byproducts of this process include glucose, which is a sugar that the corals can use as food, and oxygen, which corals need to survive. In return, the algae get a place to live and nutrients from the corals’ waste.

This type of relationship in which both parties benefit is called symbiosis. Come check out some examples of the symbiotic relationship between corals and zooxanthellae at Coral World in exhibits like the Caribbean Reef Encounter.