Yellow Tail Damsel Fading

[mbell]

I have a Yellow Tail Damsel that is losing it's color from the fin on his back and it is spreading to his body. At first i thought he had just been in a tiff with some other fish becuase it looked similar to a bite out if its fin. But it has been spreading and looking almost like his scales are just falling off. I have two of them and it is only happening to the one. I will be posting a pic soon.
35 g
Yellow tail damsel
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