Corals Respond to Day and Night

Coral reefs, which cover less than 0.2 percent of the seafloor yet provide habitats for more than 30 percent of marine life, are created by animals called corals.

Recently scientists discovered a gene in corals that responds to the light cycle of day and night. This gene, called STPCA, makes an enzyme that converts carbon dioxide to bicarbonate (baking soda) and is twice as active at night compared to daytime.

The gene is especially important in the symbiotic relationship corals have with small photosynthetic critters called dinoflagellates. The dinoflagellates use sunlight to produce energy for the coral, which in turn use that energy to construct mineralized skeletons for protection. The mineral production, known as coral calcification, is closely tied with the day/night cycle, though the molecular mechanism behind this synchronization is mysterious.

The scientists, led by Aurélie Moya of the Centre Scientifique de Monaco, detailed their findings in the Sept. 12 issue of the Journal of Biological Chemistry.

--LiveScience Staff

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Photo Credit: Didier Zoccola, Centre Scientifique de Monaco