I've had this fish for a little less than a year and he's been fine but all of the sudden today I noticed when I went to feed him he will not move from the bottom of the tank. When I did get him to move, he did it very slowly and immediately rested on the bottom again. I noticed his top fin looks like it's either clumped or missing all together and it looks like there's a large brown spot where that fin was...it almost looks like he's rotting :( His scales seem to also have a brownish tinge under light (he's blue) that wasn't there before. His eyes aren't clouded or anything either. Any idea what it is? I looked again and it looks like part of his back is a coppery/brown color; could it have been velvet? I was away all weekend so if he was sick before, I didn't know..