I have a great big white sailfin molly who is a beauty. yesterday i noticed markings on her body - 3 vertical lines, looking as if the fish bruised her ribs (if she had ribs). didnt look like anything was on the surface of the skin, but the lines were maybe a centimeter long, 3 in a row on each side, and a shade of grey. really weird. anyone have this experience? i hope it is not a disease.