Zoas are dying...

[DurTBear]

I recently purchased these zoas about 2-3 weeks ago and they have been doing find until this past week. I think something might be feeding on them but I don't know what. I don't see any nudis. But I see a lot of amphipods running around in them which causes them to close up. There is also an unknown crab that is living close to them which might be a prime suspect as well. I haven't had any success in catching him because he is so shy and never comes out. I posted on Aquariumadvice.com for ID advice and here is a link with pics and a movie:

unknown crab

Anyway, here is a pic of the zoas that are having problems. I've ruled out water conditions since all the readings are within the correct range and other zoas in my tank are fine. There are also a couple worm like things on the rock which might be spionid worms. They are thin and stringy and if you look closely in the pic, you can see an example on the top/right edge of the colony. Any suggestions?

 

[msman825]

I would dip them if they were mine. and remove the crab

 

[chadfarmer]

<a href=showthread.php?s=&postid=9463055#post9463055 target=_blank>Originally posted</a> by msman825
I would dip them if they were mine. and remove the crab

i would do the same

 

[jessp]

i'd bet on it being the crab. I had a fiddler crab that did some damage to zoas and rics. however as the others said dip and remove crab.

 

[DurTBear]

Thanks guys...I'll definitely try the dip. Would you recommend the dip that Mucho described? Or will a simple fresh water dip do the trick?

Also, any other tips to catching that crab? I've tried leaning a pint glass on the rock that he hangs out in and securing a piece of nori to a piece of rubble on the bottom of the glass.

Unfortunately, I found another crab last night that was really, really small so I couldn't get a picture...hopefully he's not feasting on the zoas too.

Thanks guys.