I have my mystery for almost 2 years, I got it at about 1 & 1/2" and it's just about doubled in size. It's the first of the wrasses to come out in the morning and the last to go to its spot for the night. It always stays on the sidelines when feeding, it will rarely go into the pack of fish (26 total) to grab food. It doesn't bother any other fish. I have my female Fiji Leopard the longest (5 years) and it's the biggest (5") of the pack. Any wrasse I've added she will chase for a few days and then loses interest. I have never seen a single sign of aggression from my Mystery.Your established mystery let you add new wrasses after the fact? I have a mystery, but I'm kind of afraid to add another wrasse. I'd like a melanarus, and an exquisite, but kind of afraid to. Did you need to use a mirror or something? Was there some fighting at first? My mystery doesn't mess with anyone except the occasional quick chase of my longnosed hawkfish, but nothing serious.