I have a bonded pair of Maroons and they don't show agression at other tank mates, but hate for anything new to go into the tank near their host....ex. Frags, new corals, hands ect.... Also my maroons do not host an anemone, but rather they host a 14" gigas clam....funny critters. My female is 5"+ and like I stated I added a starry blenny, engineer goby, copperbanded butterfly to the tank with no problems. They pair never even noticed. I also have a purple tang and a hawkfish in there as well.