Zooxanthellae question

[Salt Creep]

Some discussion has gone on recently about whether or not a coral is bleached or healthy. The statement that caught my attention was that the coral had expelled it's zooxanthellae........now I believe I know what it looks like when a coral is doing it(white stringy substance right??) but what visual observation tells you that a coral has expelled it's zooxanthellae from stress or whatever??

I just don't know and am guessing by the amount of posts that have praised the beauty of this coral vs one post about the zooxanthellae......that not a lot of other reefers can tell this by sight either.

If it's just me then you can help educate one more reefer but maybe we can help a lot of people out there improve our chances of getting a healthy coral to begin with cause at $50 and up to start it's hard to just go by "It sure looks pretty!!!!"

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www.atlasreef.homestead.com

[Doug1]

Most of the people who are good with the coral that are prone to this are sleeping now
Hopefully someone will put forth in the morning.SPS are most noticable. Anemones and clams are prone also. LPS I am limited on exp, softies as shrooms and leathers go thru pouty stages that can be hard to decipher. Bottom line, in all honesty I dont know. there are so many variables among species its hard to generalize for the ones I'm faniliar with. At last we'll bring it up to the top

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I dont advocate holding marine creatures for ransom but......since you asked
Doug, plank owner
http://hellreef.homestead.com/index.html

[Alice]

Zooxanthellae is usually brown and stringy from what I remember. A coral or anemone that has lost it's "Z" will be pale in color, sometimes almost white. There are few species of corals or anemones that are truly white so beware of an LFS telling you it's a color morph. Some corals are pale in color though so knowledge of what a healthy specimen looks like before you shop is crucial. You can find pics of corals on the net or invest in coral ID books. "The Practical Guide to Corals" by Borneman and Puterbaugh and "Corals: A Quick Reference Giude" by Julien Sprung are the best bang for the buck in that regard, IMO.

For what it's worth, I've been nursing a green cynarina, probably C. deshayesiana, for about a month that had expelled it's zoaxanthellea. It's recovering nicely, I've made sure it's fed twice a week. On the other hand, we've had some shrooms in the shop that have been without color for months that I had just about given up on. I noticed yesterday that they are starting to color up around the edges. I also know someone who's anemone bleached out and stayed that way for months, amazingly, it survived but she really babied it along. She'd had it for a couple of years before the bleaching and I know her to be a serious reefer.

Bottom line is, some survive, some don't. You need a reliable basis of comparison to determine a healthy specimen.

HTH,

~Alice

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Reefkeeping is my life; I can't afford a hobby too!

[horge]

Saltcreep,

Alice is right, zooxanthellae is "brown stringy".

"White stringy" suggests a mucus net, a food-trapping device employed by very many corals. They pay it out, then reel it back in for ingestion and digestion.

The object prey is bacteria, protozoa, and motley suspended organic goop.

hth
horge

[tdwyatt]

motley suspended organic goop

Hey, isn't that a metal band???

Hey, isn't that a metal band??? Back on topic, the stringy expulsion of zooxanthellae occurs in nature as a response to stress, and in nature, the creatures that do this have prey capture to rely on to supplement the nutrition lost when the zooxanthellae are expelled. If I get really busy this week, I will posts some pix to the webpage so you can see what they look like. Acroporae will turn rapidly white from their brown or other color base when they are injured, and unfortunately almost never recover (although this may be rtn in some instances.) Anemone that expel their zooxanthellae in home aquaria almost never recover, hence the need to CAREFULLY select the specimens for your home tank, and unless you have a good stable skimmerless system, even healthy specimens will perish in the tank after expelling their zooxanthellae. Film at 11...

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Tom <"{{{{>(
(TDWyatt)
Wise men talk because they have something to say; fools, because they have to say something. -Plato

[This message has been edited by tdwyatt (edited 02-04-2001).]

[Martyn]

Hello all.
Interesting subject:
Observation of Brown stringy stuff expelled from the Mouth/anus I would not say it is always expelled zooanthellae.
When a coral has faded or turned white by expelling of zooanthellea is not always noticed as in many situations the coral expels its zooanthellae over a period of time.
As too buying a healthy coral at the start as Alice states a reference of what the coral should look like in colours and shades and I tend too agree stay away from white corals and patchy corals.
I tend to have mainly corals from the Family Acroporidae-Pocilloporidae-Merulinidae-Denrophyllidae.
There are many circumstances that tend to cause expelling of zooanthellea and tissue deteriation and much of the time the coral looks fine when purchased from the LFS and the coral fades after purchase.
It is also important to take note of how it has been kept in the LFS and if possible how long it has been in the LFS.
Lighting is one factor that causes stress too this type of coral if just arrived at the LFS and placed under strong lighting this may shock and stress the coral it may not show symptoms of the stress straight off.
Also if it had adjusted too strong lighting at the LFS and placed under weak lighting after purchased the base may slowly bleach from lack of light which may cause secondary problems.
If the coral is kept under weak lighting in the LFS and once purchased placed under strong lighting at home this also can cause shock and stress.
Shading from other corals or caulerpa and other algae’s will restrict light and cause bleaching I had such a case when I was away for a week on my return I found too small acropora’s covered by Caulerpa Rasemosa after removing the caulerpa the two acropora’s where bleached white over a month or so they fully recovered.
Also I have found the bases of some acropora’s white from observation at night I found a couple of small snails that where eating the tissue of the base the bases did not recover but the branches grew down over the damage.
For a two-week period of fairly cold weather the temperature of my garage tanks dropped too 18c to 20c the corals in these tanks faded and polyp extension stopped after sorting out this drop in temp they have fully recovered.
I had a lot of problems with this type of corals bleaching when the systems where less than 10 months old.
Some of these corals that bleached and as far as I knew had died some have recovered the tips seem too have survived but showed no life for months then the tips of the corals grew back down over the dead lower branches.
I also found the more diversity of life I had in the tanks the better the corals seem.
Observation over time you learn that a coral is healthy and soon realise if something is amiss.

More and more I find the problems of bleaching are solved once the reason for the stress has been found and rectified in most cases now I have solved and found the reason for the stress and shock.
It maybe that it is easier to keep corals of certain family’s from the same area and environment and habitat and providing the environment for these as close as can be done than keeping a wide selection of soft and stony corals from different environments and habitats etc.
Long winded Sorry
Martyn