What Happened to my Cory?

[DreaminginBlue]

One of my panda corys has a tear in her dorsal fin. I doubt that it's fin rot, it looks like she got it caught on something and tore a little piece out. I can't get a picture because she won't stay still and my camera is awful, but it's like a triangular gash, like a small triangular piece of her fin is gone. I can't fathom that a fish bit her and took out such a perfect shaped piece, but I'm not sure.
Did she likely just get it torn on rocks or driftwood? Did another fish bite her??
My tank is all real plants, rocks, and driftwood, and the other stock are more panda corys, candy cane tetras, and a male platy.
Should I try to catch her and quarantine her? Or just let her be with her friends and do extra water changes to promote healing?
All levels are fine and she's active and behaving normally. Please help.

 

[SherLar]

I probably wouldn't quarantine just yet, unless it starts looking like fin rot. I don't think your other fish are fin nippers (maybe the platy?), but if you have any sharp edges on your rocks or driftwood, it's possible she just got snagged.

 

[Autumnsky]

A bite is possible and a easily a snag. Good clean water is a must for good healing.