I noticed recently that my round stingray has acquired brown spots on its underside (also barely visible from the top). a few days ago there were two, now there are 8. my water parameters are great and the temp is 76F. He has been in my tank for 2 months and has been doing great! still eating like a pig as well. He seems to be bothered by them and the cleaner shrimp approach the spots and pick at it (which he does and does not like). Has anyone seen this before? what do you think it could be? I have a long spined urchin in my tank as well.. could he have run into it? he is very clumsy. Thanks!