Originally posted by sammystingray
Just a note on the zooxanthellae "bacteria". It isn't bacteria, it is an algae. dinoflagellate is what you would call them outside a coral. The "algae" feed the coral through photosynthesis, and it definately is a completely seperate entity. Not that long ago, it was thought there was a single zooxanthellae living in corals, but there are many. Strangely.......corals closely related may have very different zooxan, and corals not closely related may have very similiar zooxan.....this kind of proves that they did evolve seperately, and their evolution was not so much determined by each other.....corals are two seperate lifeforms (plant and animal) living together. The coral provides shelter and access to light for the algae, and the algae feeds the coral with it's waste from photosynthesis. The coral decides how many zooxanthellae it allows to live within it's cells....ever see a coral with brown stringy stuff coming out......you were probably told it was pooping, but it may actually have been expelling some zooxanthellae to keep the balance correct. Alright, I'll stop now....I just wanted to mention it since it was called "bacteria". BTW zooxanthellae is yellowish brown, so when corals turn brown....it often means the coral is starving and is allowing greater populations of zooxanthellae hoping they will produce more food. It more powerful lighting...you may see the corals actual color instead of the brown from heavy zooxanthellae populations since the coral will actually expel unneeded zooxanthellae as the greater light provides more opportunity for photosynthesis and require less zooxanthellae to produce the same amount of food for the coral..
And that, folks, is why he is a Shark!!
Thanks Sammy!!!