A coral reef is not formed in the same way that continents are formed. Unlike mountains, deserts, and most other natural landscapes it does not consist of rocks and soil. Instead, it is a huge city built by tiny animals called coral polyps. Very, very slowly coral polyps multiply to create huge coral colonies. The reefs themselves are made from skeletons of billions of tiny animals called coral polyps.
Some colonies contain millions of individual polyps. They build up from the seabed to form unusual and wonderful shapes. The living coral colors form in spectacular shades of orange, green, purple, red, and blue. The shape of a colony depends upon the species of coral. Some species of coral are: Brain, Staghorn, Mushroom, Red Pillar, and Fire coral.
Reefs often form close to seashore or around an island. Coral reefs form in warm ocean waters. Corals normally grow in water where the salinity lies between 30 and 40 thousand. In general coral polyps are no thicker than one inch high. The polyps in a colony are connected by coenosarc, a thick layer that covers the limestone between them. Below each polyps cup is a column of limestone that has been made over the years. A typical coral reef is formed where corals can grow luxuriantly into colonies. As the corals grow larger and larger they get closer together. New corals grow between them, helping to fill the reef with coral skeletons.
Learn more about how people affect the Coral Reefs. Click the button below.