B. Class--Anthozoa. 1. Anthozoans include corals, sea anemones, sea pens, and sea pansies. These animals are either solitary or colonial polyps that live attached to a substrate (surface). Of the 6,000 known anthozoan species, corals comprise about 2,500 species. 2. The Class Anthozoa is further divided into three subclasses: Octocorallia, Zoantharia, and Tabulata (extinct colonial corals). a. Subclass Octocorallia. Polyps are characterized by having eight pinnate (side- branching) tentacles. Octocorallians include gorgonian corals, sea pens, sea pansies, organ- pipe corals, and soft corals (order Alcyonacea). Most are colonial. b. Subclass Zoantharia. Polyps are characterized by having tentacles in multiples of six. Zoantharian tentacles are rarely pinnate. Black corals and reef-building corals (order Scleractinia) are members of this subclass. Reef-building corals are also known as "hard corals" or "stony corals." Zoantharians may be either solitary or colonial.
Habitat/Distribution: Various species of corals are found in all oceans of the world, from the tropics to the polar regions. Coral reefs are generally found within 30*N and 30*S latitudes.Reef-building corals are scattered throughout the tropical and subtropical Western Atlantic and Indo-Pacific oceans, generally within 30 degrees N and 30 degrees S latitudes. a. Western Atlantic reefs include these areas: Bermuda, the Bahamas, the Caribbean Islands, Belize, Florida, and the Gulf of Mexico. b. The Indo-Pacific ocean region extends from the Red Sea and the Persian Gulf through the Indian and Pacific oceans to the western coast of Panama. Corals grow on rocky outcrops in some areas of the Gulf of California.
Habitat / Behavior: Although various types of corals can be found from the water's surface to depths of 19,700 ft. (6,000 m), reef- building corals are generally found at depths of less than 150 ft (46 m), where sunlight penetrates. Because reef-building corals have a symbiotic relationship with a type of microscopic algae, sunlight is necessary for these corals to thrive and grow. Reefs tend to grow faster in clear water. Clear water allows light to reach the symbiotic algae living within the coral polyp's tissue. Many scientists believe that the algae, called zooxanthellae, promote polyp calcification. Light-absorbing adaptations enable some reef- building corals to live in dim blue light. Reef-building corals require warm ocean temperatures (68 to 82 F, or 20 to 28 C). Warm water flows along the eastern shores of major land masses. Reef development is generally more abundant in areas that are subject to strong wave action. Waves carry food, nutrients, and oxygen to the reef; distribute coral larvae; and prevent sediment from settling on the coral reef. Most corals grow on a hard substrate.
Threats: Coral reefs are declining all over this vast archipelago due to widespread blast, cyanide, and net fishing, sedimentation, inshore construction, and eutrophication (overnutrition that favors corals' competitors).
Interesting Information: The export of corals has been banned under Philippine law since 1977. Many corals, including the blue, organ-pipe, branch, brush, staghorn, finger, and brown stem corals alleged to have been shipped from the Philippines to Leventis have been listed since 1985 in the CITES treaty. Under this international wildlife treaty, the corals are listed as species which may become threatened with extinction unless their trade is subject to strict regulation.
Conservation Efforts/Measures:

Agojo Point Marine Sanctuary Project Aquaria Water Museum Arellano University Catarman Fishermen Association Christian Children's Fund Community Extension and Research for Development Conservation and Resource Management Foundation Coral Forest Earth Station Writers' and Artists' Collective Foundation for the Philippine Environment German Development Service Guiuan Development Foundation Haribon Foundation for the Conservation of Natural Resources Hayuma Foundation International Marinelife Alliance Labrador Alternative Development Center Leyte Rural Advancement Programmes

The Miniature Reef Society Nationwide Coalition of Fisherfolk for Aquatic Reform Philippines Ocean Voice International Pagtinabangay Foundation, Inc. Philippine Rural Reconstruction Movement Pipuli Foundation Schutzgemeinschaft Korallenriff Service Bureau for Small Fisherfolks Siliman University Marine Laboratory Southeast Asia Fisheries Development Center, Aquaculture Department Southern Luzon Fishermen Foundation Tambuyog Development Center Tubbataha Foundation Working Group on Monsoon Asia ZN Center for Social Concerns and Development

Photograph Information: courtesy of the DENR and Sea World