Today I noticed that my solitary male guppy's fins had retracted, and my water wisteria's leaves had brown spots. I tried to feed my guppy, but he had no appetite. He seems to not be able to swim well either. I did a 15% water change and when I came back I noticed that my ghost shrimp was attacking my guppy's tail! My poor guppy now has a tear in his tail and I don't know what to do. Please help!! Thanks Tank specs: 69 degrees, as normal pH ~7.8, also normal In the tank I have one male guppy, one ghost shrimp, one cull cherry shrimp, and one rainbow/ Malaya shrimp.