Coral and Zooxanthellae

Coral and Zooxanthellae algae have a mutualistic relationship. Coral is found in shallow, tropical waters along the shores of continents or islands. For example, there is coral found along the coast of Australia. Coral is in fact made up of hundreds to thousands of tiny coral creatures called polyps. Corals are animals because they do not make their own food. Inside of most coral contains a plant-like, single-celled organism of algae called Zooxanthellae. Because the algae resides within the coral’s tissues, it is well protected and it is able to use the coral’s waste products from cellular respiration. The coral gives the algae carbon dioxide and other substances it needs to complete photosynthesis. Likewise, the Zooxanthellae give off sugars and oxygen as a product of photosynthesis that the coral uses to carry out cellular respiration. A fun fact is Zooxanthellae that provides the beautiful color of the coral. This ranges from golden yellow to brown. If you’ve ever heard of the major problem called coral bleaching, it’s actually because when the water gets too warm, the Zooxanthellae being removed from the coral causing the coral to whiten.
Most corals contain algae called zooxanthellae (pronounced zo-UH-zan-thuh-lay), which are plant-like organisms. Residing within the coral's tissues, the microscopic algae are well protected and make use of the coral's metabolic waste products for photosynthesis, the process by which plants make their own food.
The corals benefit, in turn, as the algae produce oxygen, remove wastes, and supply the organic products of photosynthesis that corals need to grow, thrive, and build up the reef.