Kole tang internal parasite or something else?

[PeakeAquaculture]

I have had this kole tang for roughly one month. Bought from tsm aquatics. The little guy acclimated well, seemed fine. No issue swimming around the tank and grazing. I started to notice a bulge about center mass. I'd assume in the stomach. Now there is a white line forming vertically on one side where the bulge was. The fish still swims all around and grazes but won't eat any nori I put in the tank. Is it an internal parasite or am I missing something.

 

[PeakeAquaculture]

I took a video of the fish but can't seem to post it. I'll keep trying