Corals provide the backbone of the coral reefs. While corals are often referred to as organisms in their own right, they are, in fact, made up of tiny animals called polyps. Hard corals are made up of polyps with six tentacles or multiples of six tentacles. Soft corals have polyps with eight tentacles.
Whales, dolphins, sharks and porpoises are among the most mesmerizing species that can be found in coral reefs. About 30 species of whales, dolphins and porpoises live or visit the Great Barrier Reef alone. Dwarf minke whales and baleen whales are attracted to the reefs by the vast amounts of tiny plankton and krill, which constitute their main diet. Dolphins, sharks and porpoises feed on larger fish, found in abundance in coral reefs, particularly in shallow waters in estuaries or river mouths.
Thousands of species of fish live in coral reefs. They vary in size, color, longevity and breeding patterns. For example, anemone, the fastest fish which lives in the coral reefs, can swim at nine and 1/2 body lengths per second, compared to about two body lengths per second of the fastest Olympics swimmers. On the other extreme is the seahorse, which, despite its name is not very fast and needs about two and 1/2 days to travel one kilometer, or about 0.62 miles.
The sea turtle species that can be found in coral reefs include Green, Leatherback, Loggerhead, Flatback, Hawksbill and Olive Ridley tutles. Sea turtles lay eggs in the sand. The temperature of the sand determines the sex of the turtles, with cooler sand producing male turtles and warmer sand resulting in female turtles. Sea turtles can live for up to 100 years. Fourteen species of sea snakes are found in the coral reefs. Sea snakes come to the surface to breathe every two hours or sooner.
Hundreds of bird species live on coral reefs. They include sea eagles, gulls, auks, terns and skimmers. Birds have their nests on the shore or on the islands made from or surrounded by the coral reefs. Sea birds primarily eat fish by snatching them from the surface of the water.
