I bought a 12" Silver Aro and added it to the tank to go with my 14" Black Aro. There was a stand off at first as the Black completely encircled the Silver. 2 nips later and the Silver was put in it's place. Within 15 minutes..no more aggression. They are now inseperable and even beat the Bass to all the food together. I have added a pic of them and a couple others.