Black Patches On Pike's Head?

[wrightt3]

I bought a juvenile proteus pike a few days ago and he has since developed a large dark patch going across his fore head. At first I just thought it was from the stress of being moved but seen as it hasn't gone yet I'm not so sure.
 
He seems fine other than that. He's been nice and active and is already taking food from my hand but i'm still worried that there may be something wrong with him.
 
The patch is not jet black but rather a darker shade of his natural colouring but there are also a few faint dark spots along his side, any advise?

 

[Wills]

Can you post a picture? Are you sure its not just natural colouring?
 
Wills

 

[wrightt3]

I don't think its his natural colouring because I went back to the shop yesterday and the ones there don't have it.
Unfortunately I can't post a picture because my camera is not of a high enough quality to show the patch effectively

I just noticed that there is what looks like a small white scratch of some kind in the middle...