#5. Zooxanthellae

Zooxanthellae are unicellular yellow-brown algae. These are single-celled plants that live in the tissues of animals. It is the nutrients supply for to make it possible for the corals to grow and reproduce quickly enough to create reefs. As zooxanthellae help the coral, the coral provieds protections and compounds used for photosynthesis. The relationship between coral and zooxanthellae shows an efficient exchange of nutrients in a nutrient-poor environment. Zooxanthellae often are critical elements in the continuing health of reef-building corals. As much as 90% of the organic material they manufacture photosynthetically is transferred to the host coral tissue . If algal cells are expelled by the polyps the host may shortly die afterwards. The symbiotic zooxanthellae also confers its color to the polyp. If the zooxanthellae are expelled, the colony takes on a stark white appearance, which is commonly described as “coral bleaching”.

-->What does this picture remind of something and how do they relate?


http://www.reefresilience.org/Toolkit_Coral/C2a1_Zooxanthellae.html