What to do about a damaged tail fin?

[Browndawg80]

My 55 gallon QT was empty so I made a trip to the LFS a couple days ago. Ended up bringing home 2 firefish, 3 chromis, and 4 female Lyretail anthias. The tank that the anthias were in had a total of 6-7 fish in it and at least 1 or 2 of them had damaged tails. Of course I asked the guy who bagged them up to give me the healthy looking ones. When he was finished I looked in the bag and all 4 fish looked good so away we went. Next day one of the fish somehow has a damaged tail so I'm not sure if I missed it in the store or something attacked it or what? A turbo snail is the only other living creature in the tank so unless the injury came from another anthias I'm not sure what happened. Anyway what is my best course of action from here? I had some Kordon rid-ick on hand which contains formalin/formaldehyde and some malachite green so I dosed it per the instructions on the bottle. What should be my next move?

 

[Sk8r]

Ignore it unless it's white on the edge. If that develops remove the fish and treat with an antibiotic. I wouldn't dose formalin or malachite green.

 

[Browndawg80]

And the fact that it seemingly appeared overnight doesn't change your advice?

 

[Sk8r]

I've had it appear in one minute if another fish ate it. The central question is whether the cut is clean and transparent or bloody and the other if the cut is spongy, white, or if the peduncle (the attachment to the tail, where it becomes fish) is swollen and damaged.

My royal gramma had a run-in with another fish in the previous setup and lost his whole tail clear to but not into the peduncle. Never treated it. It didn't get infected. It's now back as if it had never happened. If the peduncle is badly infected, survival/recovery is not likely. Snails don't nip tails. Fish do. I've never had an anthias, but you don't say which fish was bitten. Chromis will attack each other if they feel cramped---1 per 50 gallon is a good rule in smaller tanks.

 

[Browndawg80]

One of the anthias has the damaged tail. It does not appear to be chewed down to the peduncle and upon closer inspection I don't see any fuzzy growth or anything to suggest more than a chewed tail so I will keep a close eye. Thanks for the quick reply.

 

[Sk8r]

I really hope he'll recover with no problems for you. As you say, keep an eye on it, and if it goes white-edged, pull him to qt and medicate with, say, Furan 2... I had an eagle try to make off with my largest koi, and dealt her a terrible wound: that stuff treated it amazingly well, and Furan 2 can be used in marine, just not in the dt!