Help Save the Zoo's

[Xerxies]

Hiya folks,

I am looking for some educated opinions to help me save my Zooanthids.

I recently purchased a small patch of zoos, orange with green centers, very pretty.

I drip-acclimate everything that goes into my tank, so I'm pretty sure they went in just fine. They opened up in a matter of hours, and looked great for the first week.

Then we had a heat-wave, where my tank got up to 82F on a couple of days before I remembered to put the fans on the timer with the lights. (I don't use the fans in the cold seasons).

anyways... the temp in my tank has stayed below 80F since then.. but I still can't help but wonder if the heat was the source of the problem.

The Problem: several of the polyps (bunched together) stopped opening, turned opaque and begun shrinking. This I attributed to the heat, as it happened during the heat-wave. But since then, all of the remaining polyps stopped opening, and the mat is visibly receding, and quickly.

pertinent info:
29Gallon reeftank, 13 months old.
45lbs or LR, 2" coral-sand bed
PC lighting - three 65.watt bulbs 50% blue, 50% 10K.
wet/dry, skimmer (good), sump-pump returning 350 gal/hr.

last night's water test: no detectable ammonia, nitrite, nitrate.
PH 8.1, KH 11.5, Calcium 425-450ppm.

I have the zoos in a low-flow (but intermittent current), high lit area of the tank.

I have a coral beauty that nips occasionally, but he doesn't seem interested in the zoos at all.

did anybody make it through that whole read? if so... don't spose you can help me out?

[Mrs Smith]

Hi,
I don't think I'd blame the heat... zoas are really quite tough. Besides, many of us run our tanks on the warm side. (I'm between 80-84.) Besides, in nature, many zoas are exposed for hours at low tide under the hot sun. So I really doubt that's it.

One thought - take a close look at them, especially looking for small, odd looking snails that you didn't put in. I know of a local reefer whose zoas were practically wiped out due to one of these zoa-eating hitchhikers. She posted a pic of the snail in question on our local board - I'll see if I can find it.

Hope that gives you somewhere to start.
Danielle

[Mrs Smith]

It's the heliacus, or sundial snail.

Here are a couple of pics. I couldn't find the aformentioned reefer's pics, though.
Just a thought.

http://www.advancedaquarist.com/issu...003/invert.htm
http://www.reefs.org/hhfaq/pages/pic..._heliacus.html

Danielle

[Xerxies]

Wow, thanks for the info, Mrs. Smith. I just learned two things.
The first being about zoo-eating snails (of which I have seen no trace in my aquarium, but I'll look more closely). The second is the those sun-polyps, as I call them, are actually Zoo's. I have a healthy population of Sun Polyps in my tank, growing/dividing at a good rate. So now I am loathe to consider my problem in terms of a 'zooanthid problem'. Now I suspect it is more a specific problem with this one coral.

Thanks again for the info/pics.

[Mrs Smith]

Wait a sec... sun polyps are sun polyps - not zoas. If the species you're calling "sun polyps" are actually zoas, you'd better call them zoas. "Sun polyp" has a quite different connotation - that's the common term for a type of non-photosynthetic polyp that has very different requirements.

The parazoanthus, or yellow polyp, isn't technically a zoanthid, either. But it often gets lumped in with them.

You might consider picking up a coral book, like Eric Borneman's "Corals." It's a great reference, and can help you sort things out. Might also give you some more ideas as to why your zoas are receeding.

Danielle