Great Barrier Reef annual mass coral spawning begins

A mass coral spawning has begun on Australia's Great Barrier Reef, with early indications the annual event could be among the biggest in recent years, local marine biologists said Sunday.

Plan would protect 21 coral hot spots in Gulf of Mexico

A plan to protect corals in the Gulf of Mexico is close to becoming a law, drawing cheers from environmental groups who believe leaving the corals alone would help vulnerable ocean ecosystems to grow.

Who controls whom: Algae or sea anemone?

Bleached anemones—those lacking symbiotic algae—do not move toward light, a behavior exhibited by healthy, symbiotic anemones. Published in Coral Reefs, this finding from Carnegie's Shawna Foo, Arthur Grossman, and Ken ...

Great Barrier Reef island coral decline

A long-term study of coral cover on island groups of the Great Barrier Reef has found declines of between 40 and 50 percent of live, hard corals at inshore island groups during the past few decades.

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Coral

Alcyonaria    Alcyonacea    Helioporacea Zoantharia    Antipatharia    Corallimorpharia    Scleractinia    Zoanthidea   See Anthozoa for details

Corals are marine organisms from the class Anthozoa and exist as small sea anemone-like polyps, typically in colonies of many identical individuals. The group includes the important reef builders that are found in tropical oceans, which secrete calcium carbonate to form a hard skeleton.

A coral "head", commonly perceived to be a single organism, is formed from myriads of individual but genetically identical polyps, each polyp only a few millimeters in diameter. Over thousands of generations, the polyps lay down a skeleton that is characteristic of their species. An individual head of coral grows by asexual reproduction of the individual polyps. Corals also breed sexually by spawning, with corals of the same species releasing gametes simultaneously over a period of one to several nights around a full moon.

Although corals can catch small fish and animals such as plankton using stinging cells on their tentacles, these animals obtain most of their nutrients from photosynthetic unicellular algae called zooxanthellae. Consequently, most corals depend on sunlight and grow in clear and shallow water, typically at depths shallower than 60 m (200 ft). These corals can be major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the enormous Great Barrier Reef off the coast of Queensland, Australia. Other corals do not have associated algae and can live in much deeper water, with the cold-water genus Lophelia surviving as deep as 3000 m. Examples of these can be found living on the Darwin Mounds located north-west of Cape Wrath, Scotland. Corals have also been found off the coast of Washington State and the Aleutian Islands in Alaska.

Corals coordinate behaviour by communicating with each other.

This text uses material from Wikipedia, licensed under CC BY-SA