Hi,my guppies are doing great,about a month ago i bought a female guppy,i noticed on her one side a difrense in colour,a round shape,but now when i looked closed,she had a small hole in that colour,i removed her to my hospital tank.. What could cause this and what should i do,my tanks are well running and i do regular small water changes,amonia levels are good and so are the rst,like i said,i bought her with the the weird colour and now i noticed it wasnt just weird colour but i small hole in her.. i cant see that any other guupies in my tank has this,only she has.And she is in good health