well i had in my frag tank for awhile now never seem to mess with any other tank mates..tank mate are clowns,fire fish ,blenny,chormis, and a goby.... the other day i just added a small yellow tang for algae control he started to pick on the new guy so to be on the safe side he gotta go... his damsel side finally came when he saw a fish that was his same size... damsel will be damsel..