Clam Placement

[Reefer07]

Today I actually picked up 4 croceas. I got all of them in a good spot except for one. I have them all on the rockwork because from my understanding they like to anchor themselves to something.
The one big one I put in the middle of my tank about halfway up kept falling off. So I put a dead clam shell down and it is sitting in that now and won't fall. However, I was wondering if the bottom muscle in the clam has to actually be touching something for it to anchor. This particular clam is a good 4+ inches and the way it's sitting in the shell the bottom muscle is not actually touching the shell. The 2 sides are holding it up from the bottom.
Hopefully you guys can visualize that.
So my question is should I posistion this clam so the muscle on the bottom is actually touching the clam shell or can they anchor if they are an inch or so away from what they are placed on?

[johnnybravo234]

It should anchor itself.

[urchinkiller15]

They can anchor themselves even if they are a couple inches away from the rock or shell. My friend's clam attached to a rock 3 inches under the sand where it was placed.

[Reefer07]

Awesome...thanks for the help guys.
What was funny was one hour after I put the 2 smaller clams I got into the tank they were already anchored.
I wanted to switch the 2 but I didn't bother.

[Reefer07]

I actually have another question now.
The way I have my largest clam placed in my tank, when it is fully open its mantle is touching some of my live rock and the left side of the shell is touching the rock as well. It is kind of in between a large space in my rock setup.
I am wondering if it is ok to have the mantle touching live rock and if it is ok for the shell to be touching. Is it keeping it from opening all the way? How do you exactly know when your clam is open to its fullest potential?
Also, could any of you see placing a clam in the sandbed of a 29g tank with 4x24 watts of T-5 lighting? (crocea clams)

Thanks in advance,
Zac

[GPhiAce]

I have a Crocea in my 29 with the same lighting. At first I had him in the sand bed (didn't know any better), then I slowly moved him up to a little over half way. There he was the happiest and opened the most. Give him room to open-- that is important in my opinion.