Any zoo predators besides the commonly known types?

[Steve973]

After two years of reefing, I have a dilemma that I cannot figure out. There is an unknown zoanthid predator in my tank. This thing, whatever it is, can clean every trace of zoanthid off of a rock at a pretty fast rate. The rock, then, is devoid of any trace of zoanthid or its mat. I never had a huge amount of zoanthids in my tank, so this predator must not be 100% specific to zoanthids. I'm quite sure that it's not zoanthid eating slugs, and i'm also fairly sure that it's not a sundial snail. I spend quite a bit of time each day looking at my tank. At this point, I suspect that I have some type of undesirable worm, but I haven't spotted anything yet.

Any other ideas about what it could be or how I could figure it out?

Thanks,
Steve

 

[schristi69]

I have a colony that has been closed and declining for a couple of weeks now. See thread http://www.reefcentral.com/forums/showthread.php?s=&threadid=779131

Today I was inspecting them in the tank and saw a lump on one of the polyps with two worm like things coming from it. The lump looked like a stomatella snail shell. Wasn't the snail, just the shape of it. I couldn't tell if it was separate from the polyp or part of the polyps tissue. The worm things are a transparent green color with black rings down its length. I had noticed these worm things eariler but assumed they had come from the sand bed since I had placed the colony at the bottom earlier. So I either have a critter with very long green antennae or some worms that could have been eating the zoa. I took the colony out for a better look and can not see what I saw anymore. They could have been worms eating dead tissue or causing the problem. I scraped off several polyps that were in the stage of melting. They were very mushy and oozing. They are now going to go into QT. I am afraid this colony is a total loss. Seems a lot of folks are having zoa problems lately. Mine don't seem to have the white spots that everyone else is having a problem with though.

 

[Steve973]

I see. Well, I don't really have any colonies to inspect anymore. At the moment, just one polyp. and that could go at any time! Mine don't really decline. There here and fine one day, and no trace of them the next.

 

[coralfarm123]

Maybe some type of crab hiding in your rockwork.

 

[Steve973]

Could a crab be that efficient at cleaning off a rock? I suppose it's possible, but I'd imagine that it would leave mangled and chewed remains. And this crab would be 2 years old in an 18 gallon tank, so I have no idea how I'll determine the culprit. Putting out colonies of zoanthids as bait will get to be quite expensive, and even then I might not catch the bastage!

 

[schristi69]

You could set up a bottle trap with some zoas in it and see if you catch a critter

 

[jbplay]

I had two whitish, hairy crabs(Gorilla I think) that I'm fairly certain had a taste for my small zooanthids. They would only come out at night and would literally scrape coralline off rocks and eat it. On that basis alone I wanted them out, but they were excellent at hiding at the first sign of danger. One day I noticed that some of my little orange zoanthids were gone. I didn't put two and two together until a few days later when more were missing and I saw a few telltale scrapes on the rock. I wound up getting a larger tank and managed to capture the little devils during the move. They now reside in my sump/refugium because I'm too soft-hearted to kill them myself and don't have a mantis shrimp to do the job for me. Yet.

 

[EvilMel]

Well I suppose it could totally be some predator like a big crab or even possibly a star fish. Do you have any star fish?

I have this green serpent star (no not the green brittle star) and it mows down xenia. Not a bad deal IMO, but it is entirely feasible that one of these kinds of animals could go after some other coral. When I had thin bar xenia, it would just look like large sections of it were completely gone, with no trace at all. I mean one day...tons of xenia...next day a third of the colony would be gone. When I later got some xenia that was bigger (the branching sorta tree looking maroonish kind that everyone has) it would look like something just took a large bite off the top of it. It was totally crazy!

Then one night I camped out and saw the serpent star eating it. hah hah. It was so odd to me, but I saw it. I could totally see one of these guys (or some kind of crab) doing this. Luckily my little guy only likes certain kinds of xenia and no other corals.

I hope this helps, not too sure if it will. I just thought it might give you an idea of something else to think about.

 

[terryhendrixson]

I have a blue hippo tang that got the taste for about 3-400.00 dollars worth of my zoos and i cant catch him.

 

[Steve973]

I have a zillion mini starfish in my tank. Mini white brittle stars, mini brittle stars with gray and black bands on them, and mini asterina. These guys only seem to eat detritus in the tank, and I've never caught them eating living tissue. I can't be 100% sure that I don't have some small crabs running around if they're completely nocturnal, and I can't be sure that I don't have some undesirable worms. Maybe I'll ahve to sneak up on the tank with a red light at 3am some weekend. We'll see.

 

[heartbreak7]

Definitely check for a crab, I had the same exact thing happening to me in my tank, zoanthids completely disappearing from rocks without a trace. It turned out I had a very large rock crab that came out at night for a meal. He would destroy nearly an entire colony a night. I ended up having to take down half of my rockwork to get him out of there.

Hope you find the problem

 

[DensityMan]

No mention of the dreaded Eunice sp. worm(s) yet? Do a search here for "eunice"

From what I can recall they will clear a rock pretty fast and only come out at night. I had a colony of PPE that I watched get obliterated by a small specimen before I knew what it was. One day there were 8... then 7... then 5... then 1 and finally none. Found the little bugger later (by smashing open the rock I saw it recede into - next to the by that time missing PPE) and gave him an ice-bath.

Good luck regardless.

 

[apayne]

Steve973,

I have the same problem, last night I watched some clear shrimp (about 1/8" - 1/4"long) eating a new zoa frag I just purchased. They ate 2-3 polyps last night.

Does any one have any idea what king of shrimp these are and what I can do to control them?

Thanks.

 

[crew33]

I know peppermint shrimps have a taste for zoas. Caught one having a snack one night.

HTH.

 

[xboxhacker]

I had a mexican turbo snail mow through one of my colonies. Wasnt sure who it was at first. Got up real early while it was still dark and used a flashlight.