The word Zooxanthellae is a big name for coral pals. They are nothing but tiny algae that live in coral polyps. The polyps and the algae are good friends and they help each other. The polyps give the algae a nice home to live in and the algae, in turn, provide some food for the polyps. The algae use the sunlight to convert water and carbon dioxide into oxygen, sugars, and starches by a process called photosynthesis. The sugar is one of the sources of food for the polyps. The coral uses these products to make proteins, fats, and carbohydrates, and produce calcium carbonate.
Without the help of these algae, the coral cannot survive. Without the algae, the coral cannot display the beautiful colors that we see in the reefs. If the algae leave the coral, it will white in color. If this continues for a long time, the coral will eventually die.
On the left is a healthy stony coral. On the right is a stony coral that has lost its zooxanthellae cells and has taken on a white bleached appearance.
Most NOAA photos are available free in the public domain copyright free. All photos used on this page are in the public domain and have been used in accordance with their guidelines.
Without the help of these algae, the coral cannot survive. Without the algae, the coral cannot display the beautiful colors that we see in the reefs. If the algae leave the coral, it will white in color. If this continues for a long time, the coral will eventually die.
