Coral are amazing animals.
The tiny, one-celled creatures that live in coral, zooxanthellae, are similar to algae. The coral structure is called a polyp. It is often a hollow, tube-like structure with two ends. This mouth-like part of the polyp has tentacles which can grasp food, stun it with the tips of the tentacles, and draw it into the main part of the polyp toward the zooxanthellae. The zooxanthellae then use photosynthesis to break up the food and help the coral digest it.