Today I just lost 2 of my lyretail mollies, and now my American flagfish has a whitish lump under its scales/skin. Ammonia and nitrite: 0 ppm, nitrate: 10 ppm, pH: 7.5, temp 77 degrees F. I don’t think it’s ich because some of my fish have had ich before and that’s not what it looks like. The spot/lump is only visible from one side. I’ve attached some s, and you can see the spot/lump just above and slightly to the right of the black spot on its side in the first and third picture. Is this a disease? Parasite? New development within the fish? Tumor?