I have a small maxima clam about 2" in length maybe a little longer and lately it hasn't opened at all, sometimes it looks like it wants to but then closes right back up. another thing I noticed was some of the cleanup crew such as hermits and nassarius snails paying extra attention to the clam as if they were trying to get to it somehow. another thing to add would be that my other clam a derasa is perfectly fine. any help or ideas as to what could be the problem would be appreciated.