Basic information about corals and gorgonians on the reef.

Black Coral: Many Colors – But Rarely Black

BLACK CORALS ARE PROBABLY BEST KNOWN AS SHINY, JET BLACK JEWELRY, but in their underwater habitats as living coral they’re more likely to be found in shades of soft reds, greens, yellows and other colors. They’re not stony corals – they grow in complex linear structures resembling trees, bushes or sea fans. The “black” part is the protein-based chitin that comprises the skeletons on which dense colonies of identical, individual polyps reside. In other words,

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Sea Fans, Rods & Plumes: Thinking Outside the Calyx

NOBODY GOES TO THE TROPICS TO SEE GORGONIANS. The sea fans, plumes, rods and whips that make up Order Gorgonacea are just there, incidental bystanders on the “real” reefs of beautiful, stony corals. Sometimes, they’re in the way. While none of the 500 or so species of fans, plumes, rods or whips can compare to the exquisite beauty that hard corals achieve (although some sea fans make a good effort), they’re part of the broad

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Corallite, Polyp, Zooxanthellae

Corallite (kawr’–uh-lahyt)  The calcium carbonate exo-skeleton of a coral polyp. Polyp (pol’-ip)  With regard to coral reefs, a tiny, colonial, sac-like animal fixed to a substrate and protected by a calcium carbonate external skeleton.  Zooxanthellae (zoh-uh-zan-thel’-ee)  Symbiotic dinoflagellate algae embedded in the tissues of coral polyps that perform photosynthesis to produce nutrients shared with the host polyps. A major factor in the growth of reef-building corals.

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What Lies Beneath – Reef-Building Coral Polyps

WE’VE ALL HAD IT INSTILLED FIRMLY IN OUR CONSCIOUSNESS that coral reefs are living organisms. But, faced with the colorful, solid structures that we see when we go underwater, what does that actually mean? Those rock-like surfaces aren’t living substances themselves, but hard facades of calcium carbonate – essentially, limestone. The living animals – tiny soft coral polyps with slender tentacles – are ensconced underneath, protected by the cup-shaped calcium-based corallites they’ve manufactured. TINY, THIN

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