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Unraveling the Brain Coral

Unraveling the Brain Coral

Written by Nevin
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Published on July 10, 2010

Brain Coral are one of the more unusual and fascinating species of coral that are usually found in shallow tropical waters in coral reefs around the world. These coral are known as stony coral as the hundreds of tiny living polyps that make up the coral use a hard calcium carbonate mineral to create a stony spherical exoskeleton that has grooves and ridges resembling a human or animal brain.

Brain coral grow very slowly unlike branching varieties such as Staghorn coral and develop a strong and sturdy structure which makes them hardy against storms or hurricanes and will not break easily. It is said that they can live up to 900 years or so and the largest brain corals have been recorded to grow up to 6 feet (1.8m) in height.

Feeding on small drifting animals, Brain corals possess several tiny sweeper tentacles that lie tucked away inside their surface grooves during the day, and extend to catch food at night.  When threatened, the polyps inside the coral will retract their tentacles so that they cannot be eaten by passing predators. Apart from free floating organisms, Brain coral also receive nutrients provided by the algae which live within their tissues. The coral can also use their tentacles like hands to clean the coral surface from sand and other debris.

Divers wishing to witness a feeding brain coral which is indeed a stunning sight, should perform a night dive, and use a macro lens on their underwater cameras to capture the myriad of tiny tentacles being careful not to disturb the coral itself which will retract them at the slightest sense of a disturbance.  Most of the best Brain Coral photographs are macros or specimens isolated from the rest of the reef showing off the unique surface patterns and grooves of the coral allowing the light and shadows enhance the pattern.

There are thought to be at least 24 different types of brain coral, and often identification beyond recognizing the coral to be a Brain Coral become tricky, there are two  well known major classifications; Open Brain (Trachyphyllia) and Closed Brain Coral (Favia pallida). Open Brain Corals sometimes called Pacific Rose Coral, are usually pinched oval in shape and have two to three polyps coming off of it.