The Symbiotic Relationship between Zooxanthellae and Coral by Brianna Velasquez on Prezi
Mutualism, or a mutualistic relationship, by definition, is when two would be the relationship between hard coral and algae (zooxanthellae). Local examples to illustrate the range of ways in which species can interact The symbiotic relationship between Zooxanthellae and reef-building coral reef. Most reef-building corals contain photosynthetic algae, called zooxanthellae, that live in their tissues. The corals and algae have a mutualistic relationship.
The animal-algal mutualism that exists between a coral polyp and a zooxanthellae is an example of obligate mutualism. The coral bleaching phenomenon occurs when zooxanthellae are expelled by the coral, in which case eventually the coral will die.
Evolution: Survival: Coral Reef Connections
The anemone and clown fish is an example of facultative mutualism. The clown fish brings food to the anemone while the anemone wards off predators with its stinging polyps.
However, the clown fish could live in another type of home and the anemone could capture food from the water without being fed by the anemone. Shifting Relationships The exact nature of a mutualistic relationship may shift from neutral to positive to negative.
When corals met algae: Symbiotic relationship crucial to reef survival dates to the Triassic
These changes occur over time, with changing environmental conditions, or because of changes in the organism communities. Coevolution The symbiotic relationship that occurs in a mutualistic partnership, especially in an obligate mutualism, creates a situation where coevolution may occur.
Coevolution is a process that occurs when the genetics of one species changes in response to genetic changes in another species. Coevolution helps both species survive.
Although symbiosis is recognized to be important for the success of today's reefs, it was less clear that that was the case with ancient corals. Brown dots in a sample of modern coral tissue left indicate algae that are creating nutrients through photosynthesis that are passed on to corals. Symbiotic corals exhibit banded growth patterns right, indicated by red arrows that correspond to the availability of daylight. The algae use photosynthesis to produce nutrients, many of which they pass to the corals' cells.
Mutualism in Coral Reef Ecosystem
The corals in turn emit waste products in the form of ammonium, which the algae consume as a nutrient. This relationship keeps the nutrients recycling within the coral rather than drifting away in ocean currents and can greatly increase the coral's food supply.
Symbiosis also helps build reefs—corals that host algae can deposit calcium carbonate, the hard skeleton that forms the reefs, up to 10 times faster than non-symbiotic corals. Finding out when symbiosis began has been difficult because dinoflagellates have no hard or bony parts that fossilize.
Instead, the researchers looked for three types of signatures in the coral fossils that indicate the past presence of algae: Their analysis revealed regularly spaced patterns of growth consistent with the symbiotic corals' reliance on algal photosynthesis, which only takes place during daylight.
Frankowiak and Anne Gothmann, who earned her Ph. The third approach, determining the forms of nitrogen—which derive in part from the ammonium the corals had excreted—was conducted by Xingchen Tony Wang, who earned his doctoral degree in geosciences from Princeton in and is now a postdoctoral research fellow working with Sigman. This polished fossil slab used in the study dates to more than million years ago and contains well-preserved symbiotic corals.