Fox face markings

[Flounder's Reef]

I have a fox face that has been i qt for 2 weeks at 2.50 and has developed this odd marking any ideas

 

[vetteguy53081]

I have a fox face that has been i qt for 2 weeks at 2.50 and has developed this odd marking any ideas

Looks to me to be either Post-run marks or sting from anemone or other coral such as Hammers. Keep an eye on it for healing and not becoming sore or more pronounced