Looks like a claw in live rock

Been wondering what is it for some time. In one of my bigger piece of live rock in the larger (1/2" wide) holes, is looks like a crab claw, whatever it is is definately alive cause if you put your finger or something near it it withdraws/closes but never withdraws all the way, it feels like a hard shell, looks JUST like a crab claw. Will try to get a pic if noone knows off hand what it might be...I tried to get a close up of it but you cant really see it..

Had another item also tried to get a pic of... I fragged some zoas a month or so ago and it looks like what I fragged off the main stalk of dead coral it was covering is a small 3/4" wide scallop or something, we can see it open and if you put a finger near it you can see it close up... looks alot like a scallop to me.. just wanted to share that one cause it's so strange.

Thanks,
Tom​

 

pics will help a lot. Crabs do hitch a ride on LR and just show up one day sometimes.

 

Its been there since I got it, in fact there are a couple of them on different places, you cant see any part of it other then what "looks" like a claw, and even then there is no way it could come out of the hole, it almost looks like beek... will try to get a decent pic but only have a cam phone... either way it looks like a claw, but withdraws like a beek hehe- wierd for sure.

 

might be some sort of rock burrowing bivalve clam. I vote for pics.

 

I'm with psiclone. It will be an Ark Clam, most likely. They behave in the way you described. You can Google "arcidae" and find a bunch of pics.

Cheers,


Don

 

I had a flew clams like this as well.... but pics would help

 

I believe the ark clam is what the zoas are attached to, I will work on getting a decent pic. whats living in the live rock doesnt resemble a clam at all. strange critter, almost like he grew inside the rock and no way he is getting that fat claw out...
Tom