bug on the tail of a white tail kole tang

[corey904]

I noticed this little spot on the tail of my white tail kole tang and he doesn’t seem to be affected in any way but it’s a good reason not to bring him out of quarantine. If anyone knows what this is please let me know. The spot has been on the fish for about 3 weeks and has not moved

 

[Jay Hemdal]

Fish often develop broken fin rays, but those are typically white. When you say “bug” can you actually see appendages on this?
Jay