Can I save this injured fish?

Definitely keep that guy separate. Make sure the tank he's in is cycled and has superb water quality (no ammonia, chlorine, or nitrite, low nitrates).

Unfortunately, there's no way to say 100% if he'll survive it. Perhaps try Melafix? It's a little pricy, but it'll help with the open wounds. Some people are advocates of using aquarium salt also, although some fish are very sensitive to it. I wouldn't recommend trying salt as a first option. I would take some pictures to the pet store and see what they can recommend, as transporting him to and from may stress him out and kill him.

If your fish just ignores the food entirely, he is not eating properly. If he is making an effort to eat, that's a good sign. It'd be better if he was actively eating, but given his condition I wouldn't expect him to be swimming around to eat. Try to treat his wounds and monitor his eating/swimming habits. Unfortunately that's all you can really do. I hope it goes well.

Possibly you could save this fish infection is a worry as it has been badly attacked .

Keep up with water changes make sure your Ammonia and Nitrite are always 0 and Nitrate under 20.

I would add some stress coat keep the tank light out and wait and see.

First this is to "lalalala" Flushing a fish does not put it out of it's misery. It prolongs it for a little longer and with more pain than before. May as well cut it's head off and eat it. No long suffering just a fast clean death.

Now, he is beaten!!!! If he's swimming ok, separate him from the others and maybe add some sort of anti-biotic.

Good luck...

Its hard to say if you'll be able to save it as its been beaten up pretty bad. Best thing is to keep the water clean and the water quality good so the wounds don't get worse, it develops fin rot or other problems. Moving it around and taking it to a fish store will probably just stress it out.

Edit- Flush it as the other person says and it will suffer before it dies. Flushing fish doesn't kill them. The sewer is filled with ammonia which will burn its gills and body before finally killing it.

become the recent water dechlorinated? shop the fish calm and interior the tank, do no longer stress it greater attempting to flow it. do you have an airstone and a efficient filter out on the tank? make constructive those are working properly. it rather is recommended to discover some meds including melafix to help heal any exterior injuries. the reason your tank smells is on account which you're retaining pond fish in a tank, koi's produce fairly some waste, and what you're smelling is the ammonia from their poop. they are pond fish rather desiring a 4 hundred US gallon+ POND with filtration to flourish. i've got seen koi's pushing 4ft long! i might additionally watch the water parameters on your tank, great water ameliorations like that could kick the tank right into a clean cycle, get a try kit for ammonia, nitrate and nitrite, in case you have ANY readings for ammonia or nitrite your tank has a concern.

I personally ADORE animals!! I am a vegan and I wouldn't allow an animal to get hurt at all. But what I did learn is, sometimes I was going over board. I once had a hamster named Bubba. Over a while Bubba got sick. He was blind in one eye and his limbs were very weak. He wouldn't move, eat or do anything. I took him to the vet and they said that even if they do anything, Bubba won't go back to being completely normal and healthy. I decided to put him down. As painful as that was, I had no other choice. Seeing an animal suffer from pain and sickness just so I can have it as a pet is cruel. I took him to the vet and they put him down very gently. They gave him a small needle and he was gone to Hamster Heaven. I hate seeing animals suffer and not be happy, at least now Bubba is safe and relaxed :) What I'm getting to is, just let it go. Flush it down the toilet. As hard as that sounds, it's the best for you and the fish. The fish will die peacefully and not have to deal with anymore pain and you don't have to worry about taking care of it constantly. :)

I hope this helped :)

So? I fight bettas and they are fine afterwards. Stop stressing about an injured fish. Medicate the damn thing if it makes you feel any better.