Clowns dorsal fins missing

[Reefnski]

Hi, I have two clownfish that are missing their dorsal fins. Did they mess around with the wrong fish or is it a disease? It’s a fairly peaceful tank, but the clowns (aka Pennywise and Twisty) can be a bit territorial.

Thanks!

 

[Rocks reef]

They appear to be bitten off, if they were fighting or getting in to breeding mode, that is possible. The fin will grow back

 

[Reefnski]

Thanks! I was thinking it looked like bite marks. Is that part of the mating ritual?