Chlorophyll fluorescence in reef building corals

The ecological success of reef-building corals throughout the tropics is due in large part to the endosymbiotic dinoflagellates that reside within the gastrodermal cells of these cnidarian hosts. These algae, belonging to the genus Symbiodinium, are often referred to by the common term of zooxanthellae. This mutualism between Symbiodinium spp. and tropical and sub-tropical coral species has been a key component to the evolutionary persistence of reef-building corals since the Triassic (Stanely 2003). The importance of these algae in the long-term success of reef-building corals cannot be over emphasized, as they can contribute a significant portion of photosynthetically derived carbon to the host via translocation. The coral metabolizes this carbon, thereby meeting up to 90 percent or more of the animals daily metabolic demand from the byproducts of photosynthesis by the symbionts (Muscatine 1990)