Help ID problem w/ orange shoulder tang

[d3rryc]

Hey, there!

I got an orange shoulder tang about 10 days ago. He's about 4", and he's in my 20-gal QT at the moment, sharing space with a dwarf moray. Although the tang only picks at the frozen food, he's hammering the nori. Anyway, despite a 5-min freshwater dip a couple of days ago, he still seems to be flashing and scratching a little, so I just started him on CopperSafe. However, the real mystery to me are these blackish round/oval blotches on his body that WEREN'T there when I got him. I've attached a couple of pictures (of unfortunately low quality - sorry) with the blotches circled in red. I can't find anything in my books or on WetWeb, so any help in getting this identified so that I can start proper treatment would be greatly appreciated.

Water params:
80 degrees
1.026SG
Ammonia 0
Nitrite 0
Nitrate 0
pH 8.2

Filtration is just a little HOB moving about 5X the tank volume an hour.


Thanks much!
Derry