They can get territorial. Every fish and aquarium is different. We keep a Yellow & Purple (Halichoeres leucoxanthus) with an Earmuff (Halichoeres melasmopomus), Vermiculated Leopard (Macropharyngodon bipartitus) and Orange-Back Fairy Wrasse (Cirrhilabrus aurantidorsalis) in one of our studio tanks with no issues. I love the Yellow & Purple Wrasse for its simple color scheme. It also swims to the top and jets water when you open the lid for feeding and don't feed them right away. Cool fish!Thank you for the response. Are they known to be super territorial? I'm curious what others have experienced with this breed as they get older. Mine has grown and is almost 3 years old. Just surprised how aggressive it was to the Goby.