Symbiosis
Symbiosis
Symbiosis is a broad term describing the relationship of two dissimilar organisms living together [1]. Often one organism lives inside of another as is the case of Corals and Zooxanthellate, but can also describe an organism living in very close vicinity (think of the birds who take habit on hippopotamus' backs).
Symbiosis can be further broken down into more specific relationships such as mutualism in which both organisms benefit from each other, commensalism in which one organism benefits while another is neither harmed nor helped, and parasitism in which one organism benefits at the others expense.
Corals and Zooxanthellate
One of the greatest examples of symbiotic relationships is that of corals and zooxanthellate. Zooxanthellate are small yellow-green algae that often reside inside corals. Like other algae, zooxanthellate use sunlight to undergo photosynthesis converting carbon dioxide to oxygen and sugars. This is of great advantage to the corals; these sugars supplement or even replace their plankton diet. Then, when the corals release carbon dioxide as waste, it is consumed back by the zooxanthellate. [2]
The relationship between zooxanthellate and corals can be further classified as mutualistic because both organisms benefit. The zooxanthellate consume the corals' carbon dioxide waste as food, in turn producing sugars that serve as food for the corals. Additionally, the presence of carbon dioxide can slow the calcification of the corals so the zooxanthellate promote coral growth. [2]