mouth injury/disease???

[dowtish]

So last night my local reef club meeting was at our best LFS. They were offering amazing deals to all members. Long story short I wanted to add my last 2 fish and being that they were Tangs, I wanted to do them both at the same time. I studied the 3-4 yellow tangs very closely before deciding which one looked to be the healthiest. But they only had one Kole Tang and it was on the bottom level of tanks. The fish looked great. Fins were immaculate, color was great. So I got it. Got them home around 9pm, and acclimated them. They were swimming about in no time, and really not much hiding at all. Being that they were the largest fish, I didnt think that would be an issue anyways. But my lights were off except for the lunar LED's.

Now to th actual point of my post, and all of the above is my justification for being an idiot.

I got home from work today and the Kole Tang's mouth is seriously injured! I don't know how I didnt notice this! I want to assume that it is from being held in a tank with crushed coral and nothing else. He is nipping at the sand and biting and spitting the food out so far. So it's not so bad that it isnt eating or wanting to, but I'm not certain that it is just injury or some sort of disease. He is showing all signs of being healthy other than the appearance of it's mouth. And he isn't picking on the rocks like they usually do. Is there something that I can do, other than soak my food in selcon? Or any other suggestions??

Can't seem to get a clear pic....sorry. And sorry for the long post.

[dowtish]

bump---anybody? disease or no disease?