Random splotch of black pigment

[JustinReefAquatics]

I've had this Lieutenant tang for a couple years, looks super happy and is eating, Then I wake up this morning to a random black splotch near the tail, This fish has had black spot ick before and that looked completely different

 

[salty joe]

@Jay Hemdal

 

[Jay Hemdal]

I presume there is not a corresponding black spot on the other side of the fish? Do you have any LPS corals that could have stung it? Are there any other symptoms such as rapid breathing? If not, since it is still eating normally, I would say this is just a a superficial skin injury of some sort.

Jay