Tang Help!

[Denny-boy]

My Tang has been acting strange lately (hiding & skittish). He came out today and I noticed he doesn't look too good. Any idea what this may be? Doesn't appear to be spots but more like black blotches. He is not falling for the fish trap so he is still in the DT. I may have to tear down the tank this weekend to get him out and treat. Thanks for any help on the subject.

 

[TheTodd]

What are your parameters? What are you feeding? How long have you had it? Beautiful Tang though.