I noticed yesterday that one of my rays has some discoloration around his outside edge. It is only a couple of small spots and it doesn't seem to bothering him but I would just like to know what it is. It does not look like any type of fungus or infection just like he is losing his pigment. He is about 7" and have had him for about 5 months. Water is good and he is still eating well. I have 3 total in a 210gal with 15 discus and a silver aro. Any imput would be helpful. Thanks