I picked up a Yellow Tang yesterday, my first Tang ever, he looked really healthy in the store, i dripped him for about 2 hours before introducing him to the tank, he looked fine yesterday, other than being shy and hiding everytime i walk up to the tank. This morning i turn on my light and notice a large oval shaped bright white spot on each side of his body, that i know wasn there yesterday, I've heard the issues with ich and tangs, and I've also heard about lateral line disease (not as farmiliar with that one) Now that the light has been on for about an hour the white spots seem to be fading, they arent nearly as noticeable...is this a natural color change for the fish, or should i be concerned?