gill sticking out.

[CadetMKultra]

Right now the only fish in my 24 gallon reef is a bangaii cardinal. He was getting abused by a molly miller blenny that I gave away about three weeks ago. His fins are already growing back pretty well, but I just noticed that one of his gill flaps is sticking out a bit. What might this mean?

 

[JHemdal]

It may not be related to the blenny. Is this a long term captive fish? I've seen a high incidence of goiter in this species (I don't know why) and one symptom of that is a flaring of one or both gills. Can you post a picture?

Jay