SPS anatomy/structure question

[IPT]

My system had a failure and the salinity dropped and PH hit 10+. Amazingly most are doing OK. I have two Acros' though that are bleach white on most of the branches. Despite that, I still see polyp extension from the coralites (correct term?). At first I thought they were just dead and extended casualties, but they are not. They retract promptly it aggitated. Seems people frag as soon as they see white. The question I have is what is the relationship between the "skin" on an SPS, the health of it, and the Polyps themselves? Anyone know or had experiences like this?

 

[T Man]

Symbiotic, simply put.......the calcium skeleton is host to the zooxanthallae. On a different note.........you my friend are a phenominal photographer/artist !!! TinMan

 

[IPT]

So then in theory since the polyp's are still alive the Ca skelaton may become recolanized and the corals recover?

Thanks for the compliment. I guess you went to my website. Sorry, it hasn't been updated in a while. Here is a recent shot taken of a friend's tang.

 

[PSam]

Great aurora shots!

~ Kenai, started with red/yellow curtains from behind the mountains, wisps of green from the tips of the pines around 11pm, turned into psychedelic madness of un-worldy kaliedescope that kept me up until hours later. Most amazing thing I have ever seen

 

[redox]

it sounds like your acrs lost their zooxanthallae and ive had this hapen before on some colonies. They usually die way back but sometimes they recover with new growth but conditions must be kept constant and real strong light can make it worse

 

[mntl]

They bleached, expelled their zooxanthallae. If the tissue is still intact then they can recover but at this point they can not make as much use of the light as they are used to (they get a majority of their energy from it). For long-term survival they will need to recolonize their zooxanthallae, which even in the wild is kindof a crap-shoot. In these situations it is assumed (through most of the articles i have read) that the coral will rely more heavily on actual feeding for energy, unfortunately what they specifically need for food is not completely understood. Another point of debate is whether or not the zooxanthallae is repopulized within their tissue from any remaining ones that did not die (or were expelled?) during bleaching, or if the zooxanthallae needs to be present in the surrounding water and recollected? If it is "regrown" within the tissue, then stable parameters and just keeping it the way that it was happy in the first place should help. If it is "collected" from the water around it, then this might be more difficult because there is no way for us to reasonably measure the concentration of free-living zooxanthallae within the surrounding water in our tank.

to give you an idea of what can cause this:

Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxantheallae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within scleractinian corals. Coral reef bleaching is caused by various anthropogenic and natural variations in the reef environment including sea temperature, solar irradiance, sedimentation, xenobiotics, subaerial exposure, inorganic nutrients, freshwater dilution, and epizootics.

Link "Quote"

In other words, Silt run off, lack of plancton, too much light, too little light, too high temp, too low temp, salinity swings or extremes, water chemisty changes etc, can all cause this. Unfortunately the only one of these that is pretty well known is extended temp over 86 degrees or so. (extended as in more than a few hours).

I know there was not much in the way of answers in all that, but atleast it can help you understand what you are dealing with a little better.

-John

 

[mntl]

Sorry to keep this rolling, but another thing to think about is how did the corals look prior to complete bleaching? In partially bleached states corals tend to look very "bright" colored, infact people often comment on the "bright colors of the acros on partially bleached reefs". Some pictures to give an idead of what i mean is like these:

The pink with blue tip table shown is partially bleached (as well as all the others around it):

HERE

As with this pink with yellow tip acro:

HERE

Or the blue acro in the background:

HERE

If you have corals that are (or were) near this condition then they will not be as resilient as properly zoox colonized acros. When people show pictures of acros that are near this state then months later mention bleachin events in their tanks, it possibly could have been recognized earlier and dealt with before the corals got completely "white" bleached.

-Sorry for the ramblings

-John

 

[redox]

mntl no rambling thats just good info

 

[IPT]

John, awesome stuff, thank you. These guys were pretty densely conlonized I think. They were deep in color, with probably more brown that I would have liked, but colorful tips. I'll keep my parmeters stable, feed dirstctly with Oyster eggs and wait and see. Seems like there is no need to frag the good lucking branches off unless algae starts to take over.

PSam - you're right. On a good night the Aurora is nearly beyond description.

 

[IPT]

John, I was just re-reading your post. OK, assuming it expelled the zoo's, and it is white, how would one know if the "tissue" was still there to be re-colonized?

 

[mntl]

Polyps/tissue are still visable, polyps generally look transparent. Coral skeleton has a lot of ridges that run through/around it, the skin should be covering it and these ridges should not be clearly visible, it will look like a normal acro but ranging in color from pastel to white. Visible polyps, even small are a good indication.HERE Is a closeup of a living/bleached wild acro.

-John