Urgent. New yellow tang -- something wrong?

[winnham]

We just added the first fish to our 90 gallon -- tank has cycled and water params are good (had to add some PH buffer the day before fish came but it is still right where it should be). He was recently shipped to our LFS. He was eating and looked healthy )though thin)when I got him. Today (one day later) he is still eating and acting normally (swimming around a lot) but I noticed a tannish -- almost transparant - blotch on his top fin that I am not sure of. The only way I can think to describe it is that it looks like a butterfly wing where the color has been rubbed off a bit. What does that sound like to you? An injury? Disease? He has been eating Formula II. After much reading, it seems as if I should add nori (among other things) to his diet (which I plan to get today). What can I do before this gets serious, if anything?

[vinstr]

If he is eating and swimming fine thats a very good sign that it is nothing too serious- good be an injury...I remember my tang had something similar when I got him but now he is a bright yellow all over- I would definitely get some Nori (I use Seaweed Selects) to make sure he has plenty of greens...
But give him time to settle in and fatten up- he's had a tough, stressful journey

[reefscapes]

Best you could do at the moment is do nothing. It could be some sign of stress due to it's stressfull journey. Let it settle down and it will hopefully take care of itself. Keep it fed.