firefish dorsel shredded

[clownfish]

I have a firefish in my 30 G and yesterday I noticed his dorsel--the big, thin fin on top that lets us know he's a firefish-- was shredded. All other fins are fine and nothing else looks abnormal.

Was he in fight -- tank mates include: 2 false percs, red stripped goby; shunk shrimp -- Is he sick? Doesn't look like fin rot IME (but that's limited) ,so it could be. Any thoughts?

Parameters are mostly oky:
Amm 0
nitrite 0
Nitrate 0
SG 1.024
Temp 80-82
Ph 7.8 (Low I think -- see my other Q in gen discussion)

What if anything should I do??

 

[e-cat]

probably got biten off by the perculas, iv seen lots of fire fish in lfs with missing dorsel fins. im sure it will grow back try adding malafix and turn your skimmer off of it will suck the malafix right out.

 

[birman]

don't worry, they will grow back. i used to have 2 where their dorsels were gone after 2 days in my tank and they recovered..... till my tank was contaminated.