aggressive goldfish and shark?

best thing i have found for torn / dammaged fins in mellafix its a tea tree oil that speeds the healing process
 
I am not positive the fish in the picture is a goldfish. Something just doesn't seem right for a goldfish but I can't quite put my finger on it.

A clearer pic would help but I know how hard it can be to get a clear pic lol.
 
As far as i can see here, you have 2 options, either get rid of this fish, or just keep him and nothing else. There is a 3rd option but it doesnt always work. Get a breeder net and keep him in there for a week, then let him out. Everytime he shows signs of agression, back in the net for a few days.
 
I am not positive the fish in the picture is a goldfish. Something just doesn't seem right for a goldfish but I can't quite put my finger on it.

A clearer pic would help but I know how hard it can be to get a clear pic lol.
I'm pretty sure it is a goldfish, but for a second, I'm thinking it might just be an orfe (pic below), which are common as pets in Europe, and are sometimes pets in the US. I'd say his fish is a goldfish as a final call, though.
goldfish.png

As far as i can see here, you have 2 options, either get rid of this fish, or just keep him and nothing else. There is a 3rd option but it doesnt always work. Get a breeder net and keep him in there for a week, then let him out. Everytime he shows signs of agression, back in the net for a few days.
You might want to put out a craigslist ad, but make sure you're clear that it's nasty. If it gets nasty enough and you can't find a new home, you may want to look into it becoming food or even euthanizing it. I don't support euthanasia of fish when it's not completely necessary, but it is an option.

Just my 2 cents.
 
personally id euthanise over rehoming it to a new home in a small tank, but if you can rehome it to a knowledgable new keeper with a big tank then go for it.
 
it looks like you have decorations in your tank if you have somewhere else you could place him for a short while change around the decorations and then addd other gold fish you should be fine and he/she should be with other goldfish commets/shubunkins
 
How long has it been alone? It may have become aggressive over time, being alone an all. Try rearranging the tank a little, or upgrading it and getting a few more fish.

BTW, in the pic it looks like its missing its dorsal fin, is that true, or just my eyes playing tricks on me? Also, are those red/pink circles sores or its normal coloration?
 
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