Well, from what i have learned. the true percs have more black and it sometimes covers lg areas of the fish, whereas false percs (or ocellaris) have more of a black outline to the stripes. also tank bred false percs have brighter coloration. I would go to {EDIT LINK}, look under marine fishes, then clowns, and it shows you the two clowns and you can see the difference. hope this helps.