Corals

Corals are marine animals. They are related to anemones and jellyfish.

A coral resembles a tiny sea anemone. A coral is 1-10 millimeters big. Each coral has a ring of stinging tentacles that surround a central mouth. The tentacles wave in the water to catch food. A tentacle will sting its prey (commonly plankton) and sweep it into the coral’s mouth.

Individual corals are called polyps. Polyps live in underwater colonies. Some coral colonies can produce a hard, rock-like skeleton. Individual polyps are protected by the skeleton.

Coral skeleton’s are made of calcium carbonate or limestone secreted by the polyps. Coral skeletons can build up over thousands of years to create coral reefs.

A coral reef at first glance can look like a sculpture of strangely shaped rocks. These “rocks” are the skeletons of thousands of tiny coral animals or polyps.

Coral reefs are found mainly in the sunlit, shallow water of tropical seas. In tropical waters, coral animals receive the light and warmth they need to grow.

The most famous coral community is the Great Barrier Reef location off the coast of Australia. It stretches more than 1600 miles (2,600km). It is made up of thousands of smaller reefs.

Coral communities are extremely sensitive. They are easily damaged by severe weather and human pollution.