I'm sorry I should have said Bolivian rams do not like company of other Bolivian rams and a group of bolivian rams are not reocmmended. There are other cichlid which are more tolerable of friends of the same species.I haven't had any aggression at all, and they are often recommended as a community fish. He patrolls the tank and occasionally steals a piece of food from a tetra. Certainly no fin nipping. I could see not having too many in a small tank, or not with other bottom dwellers in a small tank, but I wouldn't tell someone they are species only.