Clownfish Disease

So i have a 10G nano that i started in my room and i got a pair of small clownfish probably around 1" in size.. one is slightly bigger the dominant one.. but my smaller one has developed some kind of disease.. it's got a teal/green looking thing that is sticking out under the gills, it looks like a small ball, some kind of infection? could it be that they were fighting a little bit and the dominant one gave it a big bite and the scar is healing/rotting? there isn't any fin damage in the subdominant one though what so ever.. and i haven't seen them fight much.. the subdominant one usually just submits when the dominant one is showing who's boss

 

wow this i a hard question! pics would help alot! i dont know the answer but ima be following this post good luk

 

Could it be a parasitic isopod?

Pills, Parasites, and Predators; Isopods in the Reef Aquarium by Ronald L. Shimek, Ph.D. - Reefkeeping.com