Hi there, I just saw that one of my congo tetras has developed into an S shape and cannot seem to swim or hold its position upright very well. It seems out of the blue. Not sure if this is genetic or something wrong in the tank. The others all seem fine. Does anyone have any clue as to what could have gone wrong? I dont think this is a fixable thing. I feek pretty bad for the little guy. Not sure if there is anything I can do.