anybody know what this spot on my star is? DUW

[wheelspin]

I have had him for about two weeks and I noticed it when I got him in the tank and was able to get a good look at him...

It does not really seem to be getting worse but not going away either...

 

[The steven liu]

It looks like an injury from the picture although I am not sure. I have the same star in my tank and they are pretty tough, has the spot been increasing in size?