More than 100 countries have coral reefs, which are mostly countries near the tropical waters of the Pacific and Indian Oceans, the Caribbean and the Red Sea.

Coral reefs are only found in warm shallow waters and sunlight is very important to them because inside them, live many plants, which need sunlight to make food.

These plants produce the food for the corals, which survive on it. However, some corals exist in the deep sea as well. They have big polyps to enable them to capture food as they have no sunlight to produce any food. Some Corals can also move around, crawling on the sea floor, looking for food.