Basic Facts About Coral Reefs

Coral reefs contain some of the largest diversity of life in the world. They are home to thousands of different plants and animals. For example, coral reefs in the Florida Keys sustain 500 species of fish, more than 1700 species of mollusks, five species of sea turtles, and hundreds of species of sponges.

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Coral reefs are typically found at a depth less than 150 feet so that they are reachable by sunlight. Corals contain microscopic algae called zooxanthellae that provide the coral with food and give them their vibrant colors and grow on average about 1 mm to 4cm per year.

Behavior & Diet

Coral reefs are made up of primitive animals related to jellyfish. Each individual coral is a tiny polyp, a very simple organism consisting mostly of a stomach topped by a tentacle-bearing mouth and is surrounded by a calcium carbonate exoskeleton that it secretes. Thousands of these identical polyps live together, each embedded in the calcium carbonate exoskeleton, which over long periods of time forms the structure of the reef. The coral animals use their tentacles to sting and ingest plankton and other small creatures.

Range

Coral reefs are scattered throughout the tropical and subtropical Western Atlantic and Indo-Pacific oceans. Western Atlantic coral reefs include these areas: Bermuda, the Bahamas, the Caribbean Islands, Belize, Florida, and the Gulf of Mexico. The Indo-Pacific ocean region extends from the Red Sea and the Persian Gulf through the Indian and Pacific oceans to the western coast of Panama. Corals grow on rocky outcrops in some areas of the Gulf of California.