We just bought a few kuhlie loaches, and one of them seems to be having problems. He is lying on his side on the bottom of the tank breathing heavy, he alternates between doing this and swimming in a rapid, small circle. I do not see any other problems with him. He was doing this in the tank before we bought him, and apparently the aquarist accidently grabbed him by mistake when we bought him (because we obviously didn't want to buy this one). I'd rather save him than take him back to die, if that is possible. Any suggestions???