Quote:
Originally Posted by Snappy
Where does the coral get it's pigment from after bleaching? There is said to be 3 varieties of zoaxanthelea and each is affected by different spectrums. We are obviously reading different studies.
|
Hmm, I read somewhere that there are more then 3, anyway here is wikipedias definition
http://en.wikipedia.org/wiki/Zooxanthellae
http://www.uvi.edu/coral.reefer/zooxanth.htm
Unfortunately I lost most of the websites that I had bookmarked when my computer crashed last year. I had a fair bit of info saved from Eric Borneman.
I believe the colour is produced by the coral to control the amount of light getting to the zooxanthella.
When bleaching occurs there is no zooxanthella to protect so the pigment is lost and in low light conditions (or high nutrients) when a coral turns brown, what you are actually seeing is the colour of the zooxanthella itself trying to absorb as much light as possible.
The pastel corals that you see in some pics of zeovit tanks are actually partially bleached corals. The tank is so nutrient poor that it is having problems feeding the zooxanthella
*edit* I realize the whole zooxanthellae/coral colouring thing is a lot more complex then i have said, but i hate typing so I kept it as short as I could
