its all about the personality of the fish, my jaguar is as touch as nails, but you cant expect yours to be if you move him from tank to tank, especially an established one, everyone here is giving you great advice you dont seem to be taking. any fish that is just introduced to an established tank has to get used to it. but once they do, and size up the tank mates it is then they realize whether or not they should take over or avoid conflict. it is also true that jaguars dont really display aggression till after a certain size, sexual maturity. the point of all this is, dont judge them untill they are big enough to show their personality, like all of us, fish are more different than you think