<a href=showthread.php?s=&postid=13074833#post13074833 target=_blank>Originally posted</a> by TJ_Burton
Crocea clams bore into rocks - they don't usually take very well to being on the substrate. It most likely buried itself trying to plant down onto something solid.
I would recommend using a sharp sterile razor to gently remove the byssal threads from the bottom pane of your tank. Press hard against the glass (under the sand) and slowly and gently slide it underneath the clam. This will cut the threads, which will in turn allow you to move the clam. If done correctly this will not harm the clam in any way.
Move the clam onto a rock. This can be somewhere up in your rock work, or simply a piece of rock large enough for the clam to sit on, on the substrate.