I've got a small gold maxima I've had since September. Was doing well until a couple days ago when it wouldn't open all the way. Today I see that it's moved from it's normal spot and is loose on the sandbed. The Byssal threads are still attatched to the rock it was on. I had a rock under the sand that it had attatched to, and the threads are still attatched to that. What would cause the clam to rip away like this?