That a Dussumieri tang but it doens't have it full adult colors. They get pretty large, mine is close to 14" and they're not very aggressive but they do control a tank. They're usually pretty expensive. I picked up a small one recently that was not doing well, almost ready to die, for $14 but it was labeled wrong.
This is a great fish to get by the way, but you need to have the room for it as they do get large.