Mine is healing up from a beating it took from a female Crenicichla sveni . So I think I might have a male psittacus growing out. He is about 5" right now and pretty shy, just starting to get some of the color in him. At what point does the aggression I keep hearing about kick in? He has got a male gold sev and a tiger oscar in the tank with him. They are all in a 210g. At this point I am thinking of getting rid of it because it is such a timid fish.