Flame Angelfish Fin Notch

[lee9]

Any thoughts on if this is a concern? I just noticed a notch in the tail of my Flame Angelfish yesterday. She doesn't appear to have any other issues.

She always eats fine and is very active. I have had her for ~ 8 weeks in my 28 gallon cube. The tank has been setup for ~ 11 weeks. The only thing I have in the tank that has the ability to nip at anythng is a Tiger Pistol Shrimp but it usually hangs out in it's burrow with the Watchman Goby and doesn't bother anything.

She's fast so it's tough for me to get a good closeup pic.