like a week ago I caught this baby catfish from a man made lake in this community. since it was small I put it in my fish tank thinking it would help clean it. after about 1-2 weeks of having the catfish in my tank I noticed one of my koi got some kind of infection on its lip and tail last night. today I bought melafix for it and just mow noticed that another kois upper fin is slightly damaged and my baby koi has some orange/yellow spots, and the female seems a little bloated/bigger or maybe its pregnant (not sure) and has been hopping out of the water or something kuz occasionally I hear a splash from my tank and today I saw the female do it, and shes also swimming so her side slightly touches the gravel once in awhile, as if shes got an itch or something. and one of my friends who put a few catfish in his tank also said that his fish grew some spots. so last night I flushed that dumb catfish. anyone know what's going on with my kois? sorry for the long post, just kinda worried about my kois.