Vocabulary Terms

Algae - diverse group of simple, plantlike organisms. Like plants, most algae use the energy of sunlight to make their own food.

Anthropogenic - relating to or resulting from the influence humans have on the natural world.

Bioeroders - marine organisms that feed on corals, weakening the coral structure by breaking down the coral skeleton and making them more susceptible to breakage during storms. Bioeroders include crown of thorns, parrot fish, sea urchin, and boring worms.

Calcium carbonate (CaCO3) - an abundant mineral that forms either by direct crystallization from water (usually seawater) or by accumulation of shell and shell fragments.

Echinoderm - common name for about 6000 living species constituting a phylum of marine animals such as starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers. They usually show a superficial five-part radial symmetry, and generally are equipped with peculiar tube feet. The phylum name is derived from the spiny skin.

Exoskeleton - skeleton on the outside of the body, such as those possessed by insects, shellfish, and other creatures without bones.

Gorgonians - soft corals, such as sea fans, sea whips, and sea rods,that sway with the currents and lack an exoskeleton.

Nematocysts - tentacles that extend and sting to immobilize prey, allowing the tentacles to withdraw and bring the food down into the digestive cavity of the polyp.

Phytoplankton - microscopic algae that generally float in the water, although some are able to swim short distances, migrating from the bottom of the reef during the day, and back up to the top at night.

Polyp - hollow, cylindrical animal with a mouth that is surrounded by tentacles armed with stinging cells.

Scleractinians - hard corals such as brain, star, staghorn, elkhorn and pillar corals.

Corallites - rigid exoskeletons that protect the soft delicate bodies of corals.

Symbiosis - a close association of animals or plants of different species that is often, but not always, of mutual benefit. The relationship between zooxanthellea and coral polyps is symbiotic.

Zooxanthellae - host algae located in the tissue of the polyp, that gives the coral its green, blue, purple or brown color.

(Definitions from the Encarta Dictionary or the NESDIS web site.)