WTF happen to my fish?

[Bizzaro]

Just got up today to clean the tank and just notice this on my clownknife... it looks like his lower was ripped open and swelled back up.... or something.... O.O! only thing i have sharp in the tank is a peace off drift wood that might be the problem.... fish are getting beaten up on all the othem so it might be fish on fish attack.

 

[nolapete]

Could be an infection, attack by another fish, or both.

 

[benzjamin13]

Looks like an infection. Maybe use some Melafix.

 

[navygirl76]

id melafix, salt and keep that water pristine

 

[haynchinook334]

Just try the salt bath first, if it gets worst, milafix. As of navygirl76 said keep temp up and water pristine.

 

[shortstack]

over crowded in the tank ? what other fish u have in that same tank?