Cold-water coral morphology and reef structure

Introduction > Polyps > Skeletons > Lophelia reefs

Cold-water corals are members of a large group, the Cnidaria, related to animals like sea anemones and jellyfish. Cold-water corals vary from solitary corals, a single polyp enclosed in a skeleton, to framework-forming colonial corals that form reefs themselves home to thousands of other animals. So far, only six species of cold-water coral have been found that can build framework reefs, compared to over eight hundred tropical species!

At first glance cold-water corals show no movement, living fixed in place. Looking closer, the minute polyps (usually just a few millimetres in diameter) are constantly outstretched, ‘feeling’ for passing prey and potential food. If a predator comes near, the polyps retract their tentacles rapidly back into the protection of the coral’s skeleton.