I have two true percs. We picked them out together at LHS because they were hanging close to each other just doing this like wiggling in unison. They have been in tank for about 5 weeks. Today one of the clowns is chasing the other around like mad and is nipping at him. I have noticed this sort of behavior before but thought maybe it was a courtship thing. Today it seems to be more aggressive and like the fish being chased is really getting worn done. I dont see any bite marks, but at one point the fish being chased was in the corner at the surface like it was low on oxygen. Is this aggression or could this be mating behavior?