That looks exactly like the beginning signs of Marine Velvet. There was a two part treatment that was highly recommend for it... but, for the life of me, I can't remember the name. I've had Marine Velvet in a few systems in the past. The fish will start to look worse and worse, and then begin to drop off like flies. You may get a survivor here or there because of healthy immune systems, but on the whole it's pretty detrimental if left untreated. Another problem with marine velvet (that I've noticed) is even if you run a tank fallow for months, it has popped back up without any apparent triggering. For example, in a 55 I had set up as a Softies only tank, I had a serious outbreak of it. All of the fish ended up dieing, and I left the tank fallow for a few months. I kept up with the regular maintenance on it and the corals and inverts did perfectly fine. Once I felt that I had left it fishless for long enough, I threw in a couple of cardinals. After another month, I added a pair of clowns. Now, keep in mind, I QT'd all the fish prior to adding them. Everything seemed fine for the next month, but sure enough, another outbreak occurred. So, I broke the tank down, gave all the rocks a acid bath and then washed them with bleach. Got new sand, and made new water, and have since not had a problem with it. I.M.O. , Marine Velvet is like Herpes. Just keeps coming back when you least expect it :\