Hey I'm new to reefing and I need help to ID and issue with my Helfrinchi goby. It develop this growth on its mouth over the course of a night. I noticed it 4 days ago, it hasn't changed since then. The goby is still eating and behaving normally. Is this a bacterial infection, flukes or did the fish damage its mouth darting into the rocks? If it is a bacterial infection or flukes is the best treatment melafix in a qt tank or fresh water dip for flukes? I'm in Canada so my options for medication are limited unfortunately. Any insight would be greatly appreciated. Thank.