When I was doing a water change today and pickled up one of my alligator snappers (I have 6, 3" individuals living together), I noticed that he did not curl his tail to the side, as they all do. UPon closer examination, I did not find and visible external damage to the tail. However, it seems as though he has lost muscular control over the tail. I will appreciate any input on this? Anyone seen this before?

Thanks in advance
AK