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NAME:  CORAL

SCIENTIFIC NAME:  PHYLUM: CNIDARIA; CLASS: ANTHOZOA

LOCATION:  FOUND IN ALL THE SEAS OF THE WORLD.  IN SHALLOW, WARMER WATERS, VAST CORAL REEFS ARE FOUND.

RECOGNITION FEATURES:  SIMILAR TO ANEMONES, CORALS ARE SMALL CREATURES WITH TINY TENTACLES, ABOUT THE SIZE OF A PENCIL ERASER.  LIVING IN COLONIES, THEY FORM CORAL REEFS, WHICH CAN BE MULTI-COLORED AND STRETCH FOR MILES.

DETAILS:

Corals are marine animals, similar to sea anemones, which live in colonies consisting of many identical animals.  Corals are divided into two different types: hard and soft.  Although all corals are invertebrate animals, hard corals get their name from having a hard skeleton, similar to chalk.  When they die, the skeleton remains which, over time, combine to form coral reefs as young corals grow on top of the dead ones.  Reefs tend to grow at about one inch per year. 

Corals have a symbiotic relationship with an algae that grows inside them, called zooxanthellae.  This relationship allows the corals to feed off the algae, which require sunlight to survive.  Thus, the corals found in such places like the Great Barrier Reef, and other warm, shallow reefs around the world, relies heavily on this relationship.  The algae, in return, is provided with a safe haven to live, and uses the carbon dioxide and nitrogenous waste for its photosynthesis.  Deep sea corals, do not rely on this symbiosis, and can live in darker, deeper water.

Many people mistake coral reefs with corals, but reefs are actually made up of millions of individual corals, each measuring a few millimeters in size.  Like anemones, corals have small tentacles (nematocysts) which are used to catch small fish, plankton, copepods, and tiny marine larvae.  These tentacles possess toxins that incapacitate they prey and move it to the mouth opening.  Most corals’ poisons have no effect on humans, but the toxins found in fire corals, can sting humans and cause serious pain.  Corals have either 8 tentacles, or multiples of 6. 

Corals are fairly simple creatures, consisting of an opening that serves both as a mouth and an anus.  This opening is surrounded by a series of tentacles that push food to the mouth.  The base of the coral—where it attaches itself to a stationary location—is made up of a calcium ring, which extends with age and also provides a protective place in which the coral can retreat in times of danger. 

Coral reefs are found all over the world, from southern Argentina and Chile to as far north as Alaska and Scotland, but mainly are located in shallow tropical waters such as Australia, the Caribbean, Madagascar, and southeast Asia.  These reefs are extremely important habitats, providing ecosystems and havens for thousands of species of fish, mollusks, crustaceans, and other marine life.

Corals are extremely sensitive to environmental changes, and many scientists feel that within 20 years, half of the world’s corals will be destroyed.  Coral will die if the temperature changes by more than one degree, and will be inundated by algae if there are too many nutrients in the water.  Divers, anchors, and reef fishing also damage this sensitive ecology.  Many governments have enacted strict laws to protect the removal of corals, and education programs are being taught, but the damage continues.  In 1997-8, warming in the Caribbean bleached and killed a native coral population in Panama and the species is now thought to be extinct.