I just then when I went to look at my goldfish tank and I noticed that my Shubunkin had it's tail fin torn a bit. And I would stay in one spot down the bottom breathing heavy.He is also not very active. It also had some of it's scales sticking out. It's always had this thing with it's tail and it's scales and I would mend them but then it just happens again. But I have never seen it down the bottom of my tank gasping for air it is normally one of my most active goldfish. Please help.