Everybody posts from time to time about Oscar tank mates. What works, what does not. Tank size minimums etc. I got a 150 up and running about a year ago and decided that I'd get a couple of oscars and a school of some dithers. Both fish went into the tank at the same time and for the most part everything has been fine. Some minor spats here and there. Well one of the 2 O's had gotten a little bigger than the other. The other night a heard a noise come from the tank which is in the living room about ten steps from the bedroom. I thought that one of them got spooked and hit the lid as usual. I woke up the next morning to find the smaller of the 2 oscars beat to hell and shredded. almost one pectoral fin is gone and it looks like an iron was pressed on the entire right side of fish. Not to mention other lacerations. At first I thought it was dead, but noticed gill movement. I thought about euthanizing, but he still had alot of fight when I removed him to go into a hospital tank. 3 days later the fish is eating again and starting to heal. Part of the missing fin has started to regenerate and other cuts are filling in. This fish is now called lucky and the other is *******. My conclusion...never trust those puppy dog oscar faces.