Sick clown

[racecaraz]

I have a False Perc clown that has developed a bulge behind its left pectoral fin. I can see a dark mass under the skin that has a thin white line going through it. It is still eating fine but has been less active, spending much of the time in the corner of the tank. The other clown(slightly larger false perc) has developed a new aggression toward the ailing clown, and will charge if it starts to leave the corner. They have been fine in the tank together prior to this.

I have since separated the two, but the sick fish acts much the same.

Any Idea on what this mass could be? Thanks

EDIT: BTW I tried to get a picture, but was unsuccessful.

 

[Percula9]

Remove immediately to a sick tank. Treat with Furan2 or Maracyn2 for 7-10 days. Fish is probably developing a bacterial infection. Treat it before your fish dies.

 

[billsreef]

Does that thin white line look like something drawn on the lump, or a thread attached to the lump?

 

[racecaraz]

Percula9: I removed it to the QT tank, due to the sudden aggression of the other clown.

Billsreef: Difficult to tell, definitely on top of the lump, but still under the skin. I would lean toward a white line drawn on top.

Thanks everyone for their help, will anxiously await a reply.

 

[Percula9]

Sorry I wasn't sure how you separated them. Some people put dividers in their tanks to separate fish that are being attacked. I still recommend treating with antibiotics. Hopefully this will cure him.