Suggestions On Ridding Myself Of Zoanthid Eaters...

[sothoth]

I have a generally VERY happy 30gal reef tank. I have several corals, including my favorites, zoanthids. I also house a pagoda cup, xenia, anthelia, and open brain, a few types of star polyps, a tree coral, a tube worm, and three fish (dartfish, 6-line wrasse, and a goby).

All were fine until...

zoanthids started to dissappear QUICKLY. I had a rock with about 100 animals on it one night, the next morning I was down to about 70 animals, and over the next couple of days, I was down to ZERO on that rock. Then another rock was hit. I had about 30-40 animals on this one, and they all disappeared too. And when I say they disappear, I mean they disappear. They don't close up, they're just gone.

I'm guessing it's one of two things, either those zoanthid "spiders" that I hear about, or the nudibranch that eats zoanthids. I have never seen what it is, and believe me, I've looked carefully.

I just tried a dip, purchased at my LFS. It's a concentrated iodine solution that should be good for killing off the nudi's but I don't know about the spiders. Any suggestions? I know it's hard to say without identifying what is doing this, but if you have general remarks or suggestions that I should follow IF the culprit is the spider or IF the culprit is the nudi, or IF it's something else, I'd greatly appreciate it.

THanks!

 

[Mr Miagi]

zoanthids started to dissappear QUICKLY. I had a rock with about 100 animals on it one night, the next morning I was down to about 70 animals, and over the next couple of days, I was down to ZERO on that rock. Then another rock was hit. I had about 30-40 animals on this one, and they all disappeared too. And when I say they disappear, I mean they disappear. They don't close up, they're just gone.

You mean polyps? This sounds NASTY!

I just tried a dip, purchased at my LFS. It's a concentrated iodine solution that should be good for killing off the nudi's but I don't know about the spiders. Any suggestions? I know it's hard to say without identifying what is doing this, but if you have general remarks or suggestions that I should follow IF the culprit is the spider or IF the culprit is the nudi, or IF it's something else, I'd greatly appreciate it.

All I can say is observe the Zoanthids VERY closely. Perhaps use a magnifying glass. Other than that, im all out of suggestions. If your water params are ok, and other species of coral are doing ok, it must be a predator.

 

[sothoth]

All I can say is observe the Zoanthids VERY closely. Perhaps use a magnifying glass. Other than that, im all out of suggestions. If your water params are ok, and other species of coral are doing ok, it must be a predator.

Is there anything that would cause them to stop sticking to the rocks on their own? Although it sounds silly, and I've never heard of that, its indeed strange, so I don't want to rule out strange causes.

All other corals are in good shape, water parameters are good (verified by my LFS as well) so I'm perplexed unless it's a nudibranch or a spider. I hear the spiders are slow to eat zoa's so I'm still guessing it's a nudi. Yech! Why are the good nudi's so hard to keep and the pests hardy as heck?

 

[n3ont3tra]

HAve you tried looking in the tank in the middle of the night with a red flashlight?

 

[keith00]

Have a look on this board under Advanced Topics which is run by Anthony Calfo. There is a thread for Zooanthid spiders.

http/www.reefcove.co.uk/forums/index.php?act=home

 

[Navarre]

zoo spiders... generallly very very hard to get rid of... The only come out after dark so check the tank after its been in darkness for a couple of hours. They dont move fast so when they have been seen they can be removed easily. I suggest you observe after dark and if then dip the zoos when rhe spiders are visible.. once they burrow into the poylp or liverock they cant be harmed by the dip so its a long and rawn out process.

I know aperson who has a zoo colony that he has been dipping since last sepember and he still hasnt got rid of these spiders

 

[sothoth]

Wanted to give folks an update on my zoanthid disappearances.

I'm not 100% sure yet, but I think I've pinned down the disappearing corals (esp Zoanthids) to a snail, probably a Coralliophila sp.. I won't be sure for a little while, but this one seems to be a culprit, if not THE culprit.

All of my Zoa's eventually disappeared and I spoke at length to the guy who owns the LFS that I frequent. He's VERY knowledgeable. He suggested buying a very small colony of Zoa's, and keeping them in a tray in my tank with live sand in it. So I did exactly that, and once the new ones started to disappear, I pulled out the tray (with the live sand and the Zoa's) and picked through it until I found a snail (but nothing else).

The closest ID I could make was the Coralliophila species listed here:
http/www.unep-wcmc.org/marine/coraldis/cd/snails.htm
or here:
http/home2.pacific.net.ph/~sweetyummy42/Hitchsnails.html

And incidentally, this is a decent pair of web sites to pass along anyway, since it has plenty of other good info as well.

The snails look just like the ones that pop up if you do a google image search for the term "Coralliophila."

Hopefully I don't have more than one, I picked out only one so far and don't see others. I'll be keeping my fingers crossed for the next several days that this was really the culprit.

Also, for anyone who cares what I ended up doing with my crab, I plopped him in the 'fuge and he's doing just great in there. He was really hard to get out, I had to put every bit of rock and coral in a bunch of buckets and then, with a flashlight, look over every nook and cranny until I found the crevice he'd been hiding in. It took me a while to pick him out without hurting him. But he was very destructive so I'm glad he's gone. He kept knocking over corals like mad so I'd come home and find polyps upside-down on the sand all the time. A few died this way, so it was time for him to receive his eviction notice.

 

[sothoth]

Ridding myself of the snail seems to have stopped the zoanthid death. I'm 99% sure this was it.

Down with the predatory snails!!