Okay, my first sickness...or whatever it is. One of my bloodfin tetras has this weird lump on his side. It looks like a tumor. Do fish get tumors? Or a big giant fish wart. It's underneath his skin, not on the outside. It's not discolored or anything. What is it? Should I quarantine him? I'd take a pic but he's too fast for my crappy camera, he would just come out as a blur.