Clownfish fin rot or battle wound?

[JCrowe86]

Noticed that my smaller clown is now missing a good portion of his tail fin. It's had the spot on top since I got him around 3 months ago. I've never seen any fish show any aggression to either of the clowns and the 2 have gotten along ever since I introduced the smaller one. Again they've been together at least 3 months. No other fish shows any signs of fin rot or any other damage.

 

[Big G]

Clowns can be real aggressive, especially as they mature. A member reported that his clown jumped up out of the tank and bit him on the eyeball as he was doing tank maintenance. Yikes. When there are more than one clown in a tank, things can get interesting. They are after all part of the damsel family.