Interesting Acro question

[marie]

Well if it keeps the new colour it will be a show stopper of a coral.


Almost makes me want to force the rest of my corals to bleach

JK...maybe

[niloc16]

marie i would definitely get it out of your system right away. send it down here to me and i'll see what i can do with it, ok

[Snappy]

Hopefully the purple zoaxanthelae in that piece will continue to stay dominant for you. Acro's can often be predictabley unpredictable.

[marie]

Originally Posted by Snappy

Hopefully the purple zoaxanthelae in that piece will continue to stay dominant for you. Acro's can often be predictabley unpredictable.

Just for the record there is no purple zooanthellae. All zooanthellae are varying shades of gold/brown, it's the coral pigment itself that gives you different colours.

[Snappy]

Originally Posted by marie

Just for the record there is no purple zooanthellae. All zooanthellae are varying shades of gold/brown, it's the coral pigment itself that gives you different colours.

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.

[marie]

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

[marie]

And here is another link (it's steven pros rant of the month way back in june /06 )

http://forum.marinedepot.com/Topic37...=zooxanthellae

[Snappy]

Originally Posted by marie

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

Yes. Zooxanthellea are symbiotic algae that live in the gastrodermis and are photosynthetic. They produce carbohydrates for the coral to feed off of.
But in a nutrient poor environment like zeovit it is often a deficiancy of potassium that lightens the colours. The coral will expell some of the zooxanthellae it doesn't need in brighter light because their photosynthesis is more productive and the coral only keeps what it needs.
Clams also contain them and interestingly enough I've seen a blue clam go
brown when there isn't enough light. Anyway of course the coral does have a pigment and most zoox are brown but not all. Expelling the brown zooxa lets the coral get the nice colours but it still has them and they are not all brown. I think we are starting to split hairs now. For the most part we agree.