I have a 7 to 8 in female cuban a 4 in female cuban and 4 in male cuban and the 2 females are in my 125 gallon tank and they are fine with each other but go after anything else in the tank when something comes in there area. Like when i was cleaning my tank the other day my 2 females attacked my hand. my male is really aggressive towards anything that isn't a female he only attacks other males in my 75 gallon so they are aggressive and will attack when to be but not to bad