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Shelves of coral surround the Pacific island of Palau. Corals, small organisms related to anemones, secrete calcium carbonate, which hardens into an exoskeleton and over time forms reefs.</p>
Coelenterate Coral
Shelves of coral surround the Pacific island of Palau. Corals, small organisms related to anemones, secrete calcium carbonate, which hardens into an exoskeleton and over time forms reefs.
Coral Kingdoms
See coral kingdom photos, from National Geographic