Characteristics:Butterflyfish can be aggressive towards other Butterflies, especially ones of the same specie and sex, as well as other species that are similar in appearance. Care should be taken if introducing a new Butterflyfish into a tank where one has already been residing. The established Butterfly might pick on the new one, because they can be very territorial. It is best to introduce them into the aquarium at the same time to help reduce conflicts. Disputes settle down once the fish have worked out tank arrangements for living. Giving this fish plenty of room and hiding places also helps to lower potential conflicts.