The actinopharnx (stomodeum) is an irregularly shaped tube extending from the mouth of the polyp into the digestive cavity, or coelenteron. Most corals possess two biradially arranged longitudinal evaginations, the siphonoglyphs. The siphonoglyphs are lined with flagellated cells which drive water into the coelenteron. Longitudinal sheets of tissue, the mesenteries, extend radially from the body wall. Some extend all the way to the actinopharynx. Mesenteries attached to the siphonoglyphs contain muscles which allow the polyp to retract. The mesenteries also contain specialized cells which function in digestion. The calcified radial septa of the scleractinian skeleton lie between pairs of mesenteries.
What are Coral Reefs?
Appearing as solitary forms in the fossil record more than 400 million years ago, corals are extremely ancient animals that evolved into modern reef-building forms over the last 25 million years. Continue Reading →
coral reef conservation program
The NOAA Coral Reef Conservation Program (CRCP) is a partnership between the NOAA Line Offices that work on coral reef issues: the National Ocean Service, the National Marine Fisheries Service, the Office of Oceanic and Atmospheric Research, and the National Environmental Satellite, Data and Information Service. The CRCP brings together expertise from across NOAA for a multidisciplinary approach to managing and understanding coral reef ecosystems.
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NOAA's Coral Reef Conservation Program
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NOAA's Coral Reef Information System
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