I recently added a small Mono Sabea to my brackish tank and he is nipping at my Violet Goby's fins constantly. My Goby is such a pushover he doesn't do anything but run. I've never had any of my fish nip at him until this guy came along. I just finished setting up a nice pile of rocks for my Goby to hide in and the Mono can't get to him. Just curious if it's common for Mono's to be fin nippers?