This was something i have cut and paste here for you from www.fishplace.org
The ocellaris clown also goes by the name false percula because it closely resembles the true percula clownfish, A. percula, which came on the popular market first. The main differences are just that the markings of the true perc are darker and that it proported to be slightly more territorial, but they are basically very similar and closely related (there is another difference with the number of rays in one of the fins, I think, but I don't remember it). Either way, both species are very hardy. Specifically, the false perc makes an almost perfect beginner's fish for the community FO (fish only) marine tank, or the reef tank, large or small. Unlike the maroon clown, this is a small species that will stay small (they don't get much bigger than 3-4") and can be kept in a tank as small as 10 gallons in size (these are considered "nano"). The fact that they stick to a small territory and do not need lots of swimming room, unlike the hippo tang also makes them ideal for smaller tanks. They also have other good qualities. Unlike other clowns, they are not too quarrelsome, either with their own species or each other. They can be kept in small groups if they grow up together and will not try to kill other clowns, unlike more aggressive species (such as the tomato clown, which would attack a peaceful clown such as the false perc and try to kill it). They are hardy and will tolerate a wide range of marine conditions, within reason of course. And they are brightly colored and lastly, not hard to feed.
Hope this helps
