Fin damage

[N2theUnknown]

So could anyone give some insight on what I should do. Noticed my wrasses tail looking like this. It's just happened withen the past few hours. I have 2 clowns and the wrasse in a 40b. The clowns show no aggression towards the wrasse. I shouldn't have any unwanted hitch hikers as all rock was dry and same with sand. Is this something that could have just happened on a rock? Should I medicate with antibiotics? Thanks in advance everyone!

 

[Flippers4pups]

I would place bets that one of the clowns nipped it in passing. It should heal on its own if water quality is pristine and quality frozen food fed.

Clowns will defend their territory, if only in passing by.