So my biggest datnoid is breathing heavily, right underneath the mouth/gill area is pink. He is also constantly scratching himself against the driftwood. He is however still eating very good. Its not the side gill area, but right underneath the gill area that is pink. All my datnoids seem to be breathing hard, but only my biggest datnoid has the pinkish area under the gill area. Gill flukes? If so then I would probably use prazipro