i have a yellow tail that is a little bigger than my pair of clowns and he pretty much controls one half of the tank and the clowns have the other... when I added my black ocellaris, the ocellaris that had been in the tank before him naturally started picking at him for a while, then when the damsel came around, the older ocellaris stopped messing with the new clown and protected him from the damsel... so who knows.. might help with pairing? btw... 4 stripe and 3 stripe damsels suck... meanest little **** ever....