Large spot on Blenny

[Dondante]

This showed up today. Could it be from a fight? He challenges everyone but nobody ever takes him up on it. Except my really young tang who is learning he can bully. Haven't seem them actually fight.

On his left side low towards the rear. Around the 4 or 5 second mark. Couldn't get a picture. So I had to capture on video.

Thanks in advance.

 

[HotRocks]

It looks like an injury from what I can see. Very difficult to see even in the video.

 

[Dondante]

He's so difficult to film. It's not raised at all. Very strange. It's skin level .Not raised or indented etc.