Clown tail injury from aggression?

[mr11]

Hello again,

I added a second clown last night. It had been 2 weeks since adding the one in the picture. They are both about the same size and juvenile. Woke this morning to find the tail shredded on my first clown. Aggression or something else? Will he be alright? He seems to swimming fine. I haven't tried feeding yet.

 

[mr11]

He's eating, the tail looks pretty bad though. It's all the way down to a nub kind of. Seems kinda swollen around the injury site too.