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In this short article I will be going into the very, very basic science of the relationship with coral and zooxanthellae. I believe it is necessary to understand this relationship to successfully keep corals, and I remember it was difficult for me to understand when I was a beginner, so this is why I will be using basic terminology and keeping it simple.
The symbiotic relationship began approximately 200 million years ago, during a period of increasing coral diversity. As coral thrived in warm, shallow waters, they encountered the end-Triassic mass extinction event.
(Photo credit @luis angel)
It’s no secret, corals can get food themselves. A majority of living organisms on this planet can only get food through predation; but that is not true with corals. Corals can predate, but they also get help from a dinoflagellate called Zooxanthellae. As mentioned, Zooxanthellae is a type of dinoflagellate which is really just algae. They are single-celled, and roughly about 5 to 2,000 micrometers in size. Corals have evolved to house zooxanthellae in their tissue.
Zooxanthellae performs photosynthesis. (If you know how photosynthesis works, you can skip this paragraph.) Photosynthesis is a chemical reaction that takes place in chloroplasts. The organism takes in Co2 (Carbon Dioxide) through stomata (Stomata are little holes in the plant cells). The organism also takes in H20 (Water), and light. After the chemical reaction has occurred, the chloroplasts have created O2 (Oxygen) and a food molecule (Amino Acids, Glucose, ETC).
After photosynthesis has occurred in the zooxanthellae, it is left with a food molecule. This food molecule goes to the coral; unless the dinoflagellate needs it to grow and reproduce. This is very efficient for the coral; this is its main food source. The nutrients help the coral create skeleton and grow new polyps (AKA reproducing as each polyp is an animal). The coral provides a safe space for the zooxanthellae to grow and reproduce.
Zooxanthellae, also provides the coral with its color. Do not get this confused with its fluorescence, though. The fluorescence is not provided by zooxanthellae. Instead, the fluorescence comes from proteins within the coral.
(Photo credit @kevgib67)
The symbiotic relationship began approximately 200 million years ago, during a period of increasing coral diversity. As coral thrived in warm, shallow waters, they encountered the end-Triassic mass extinction event.
(Photo credit @luis angel)
It’s no secret, corals can get food themselves. A majority of living organisms on this planet can only get food through predation; but that is not true with corals. Corals can predate, but they also get help from a dinoflagellate called Zooxanthellae. As mentioned, Zooxanthellae is a type of dinoflagellate which is really just algae. They are single-celled, and roughly about 5 to 2,000 micrometers in size. Corals have evolved to house zooxanthellae in their tissue.
Zooxanthellae performs photosynthesis. (If you know how photosynthesis works, you can skip this paragraph.) Photosynthesis is a chemical reaction that takes place in chloroplasts. The organism takes in Co2 (Carbon Dioxide) through stomata (Stomata are little holes in the plant cells). The organism also takes in H20 (Water), and light. After the chemical reaction has occurred, the chloroplasts have created O2 (Oxygen) and a food molecule (Amino Acids, Glucose, ETC).
After photosynthesis has occurred in the zooxanthellae, it is left with a food molecule. This food molecule goes to the coral; unless the dinoflagellate needs it to grow and reproduce. This is very efficient for the coral; this is its main food source. The nutrients help the coral create skeleton and grow new polyps (AKA reproducing as each polyp is an animal). The coral provides a safe space for the zooxanthellae to grow and reproduce.
Zooxanthellae, also provides the coral with its color. Do not get this confused with its fluorescence, though. The fluorescence is not provided by zooxanthellae. Instead, the fluorescence comes from proteins within the coral.
(Photo credit @kevgib67)
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