Emerald crab eating zoas?

So, I'm not sure if it actually did or not, but it looks like my emerald crab may have ripped a few of my zoas off their rock... there's little zoa-shapped holes where there once were healthy little corals, and the emerald was sitting next to the frag eating. I thought they only ate algae? How likely do you think it is that the emerald would eat zoas? Just trying to figure if I should take this guy back to the LFS before my corals are decimated....

they're a crab.... so they can't get trusted 100%

I'm a firm believer there are no rules written in stone in this hobby... at an LFS we once had a yellow tang wipe out an entire shipment of cleaners and peppermints...
+1 Nathan
Any fish or invert you buy.You can figure you got a 50/50 shot of actually behaving normally.
aren't zoas pretty toxic? I would think they would stay away from it!
I have a large collection of emeralds and they've been behaving with my zoas, but like everyone said, you never know! Do you have any fish that may have took it down and the emerald was just munching the leftovers?
All I've got is two clown fish-- one's a baby and avoids the zoa's most of the time-- and one quite shy goby, so pretty sure the fish aren't doing it. My hermits and snails ignore the coral frag altogether. I did do an iodine dip for about an hour before adding the coral, and this is the only coral I've got-- I thought that would kill nudis? Also, what exactly do they look like/how big should they be, if I do have one? Never seen one before.

Thanks for the suggestions!
I would be very suprised if your emerald crab is eating your corals. My emerald crab will annoy my zoas and xenia when he cleans the rocks they are on, but he does not eat them. When he runs over the corals the corals will contract, but once he is gone they come back out again.
Those are sundial snails -- known coral eaters. I'd say it's pretty certain that those are the culprits, not your crab.

What you can do to get rid of those guys is give your zoanthids a freshwater bath. Fill a container with RODI water, heat it up to nice reef temperatures, and submerge all your zoanthid rocks in the fresh water for 5 to 10 minutes. Any "bad guys" like zoa eating nudis, spiders or snails like yours should fall off. You can help them along by gently blowing on the zoanthids with a turkey baster in the water.

You'll want to get rid of those guys before they have a chance to make a meal of your other corals -- they work fast, so get to dipping ASAP.

You may have to re-dip them the next day, or for a few days after that to make sure you got rid of them all.
+1 Biff
You'll also need to look for their eggs.They'll look like clear,yellow bags.You'll need to brush them off with a soft tooth brush.
wow, that solves that mystery. Thanks guys!! Just one question though-- the zoa frag also has xenia on it. will the water dip hurt the xenia?

thanks again!!
it wont hurt the xenia either, also know that every time you buy a wild caught zoa colony you have a huge chance of this happening again so i suggest buying aquacultured frags of zoas from now on
Thanks for the suggestion... the guy told me this zoa was aquacultured, but I know some other frags in the same tank weren't. Probably got the hitchhickers that way :)

I did the freshwater dip, and cleaned the coral yesterday. Got rid of one more snail and bunches of white stuff that I"m assuming are the eggs. But ever since then the xenia has been closed up tight, and this morning when I looked, some of its fronds (Or whatever they're called... the little things that pulse) are completely gone. Is there another snail or something eating the xenia, or does that happen when you do the FW dip, or what?

Thanks guys!
Agreed.Xenia is a temperamental coral to begin with.But their tough as nails.
They should come back,their probably just pissed at being dipped.