Chromis losing scales?

[Tristan]

25 gallon tank
Livestock:
Firefish
Pinkbar Goby
Clownfish
2 Blue/Green chromis

Recently I've noticed that one of my chromis has been losing scales. I'll look at the tank at night with a flashlight and see the missing scales on the chromis. I noticed this about a week ago and since then he/she has lost a few more but not a lot. I have seen the 2 chromis go at it in short bursts but not actually beating each other up.
The chromis does sleep in a little hole in my rockwork so could the missing scales be due to him accidentally rubbing against the rock while "sleeping"?

 

[Humblefish]

Notice any redness or white spots on the fish?

 

[Tristan]

Notice any redness or white spots on the fish?

Nothing nada.

 

[Humblefish]

Nothing nada.

I would just monitor for now. Post closeup photos of the fish if you can.

 

[Tristan]

I would just monitor for now. Post closeup photos of the fish if you can.

I'll try. You can't see the missing scales though when it's lights on

 

[melypr1985]

I'd like to see the best pictures you can get also. I doubt it losing scales from bumping into the rocks at night. I wouldn't worry too much at this point, but pictures always help