I mean it’s kinda strange cause these fish have been together for about 8 months never a problem. I have the goldfish with three other Ryukin goldfish and 4 angel fish only 2 of them are small and the other 2 are adult angelfishes. I do have one Yo yo loach and a small red tail shark and a pleco. That’s pretty much it. Do you think than it was an attack the reason why to be honest I don’t think ? it is because the other eye ? is getting large like it looks like it’s going to pop. I have to inform you that this fish I got it from someone who wasn’t properly taking care of it so I took and he was doing fine with me until now. I am a bit worried about his eyes if they might pop. I do water change every Saturday and atleast 50 percent. I did you Melflix and API salt to see and I used ammonia conditioner as well. I guess all I can do is watch him. I get the feeling he won’t make it.
View attachment 1426951
This sounds about right At about 8 months of age angelfish start to teach sexual maturity, you may have a pair now trying to defend a potential breeding site. Maybe they have already laid eggs?
I also found my yo-yo was trying to attack my other fish when I owned them as well, I quickly re-homed.
I cannot comment on the red tail shark but have a feeling he too could have caused some damage.
The pleco, if a common pleco could also be causing damage to the goldfish by trying to suck the slime coat off.
It just sounds like you have a very mixed bag of fish that are not compatible. You should either separate all goldfish into their own tank, re-home the goldfish if no other tank is available, or re-home the other fish if you want to keep the goldfish.
The other eye that you say looks like it is going to pop could be due to poor water quality, though I’m not sure of your tank size I’m assuming it’s much too small for the stock you have.
Goldfish are messy fish and most people do not provide them with enough water changes. When I was keeping 3-4 goldfish in a 60g tank I was doing 90% weekly water changes and it still wasn’t enough, my white fantail often had red steaking in the fins a day or so before the scheduled water change. I highly doubt 50% is adequate for your current stocking.
I know you say it came from a tank that was uncared for, yet you say you’ve had it for 8 months...8 months isn’t more than enough time for the goldfish to recover from the previous tank conditions. The problems you are currently seeing are a result of your current care or lack there of.
I’m not trying to be insulting in anyway, I think you might be new to fish keeping and you are trying you hardest to provide the best home for your fish. I have no doubt about it, that’s why your here asking questions which is fantastic! Please don’t stop learning!
I really think your problems come down to incompatible tank mates. Take some time to research the fish you have, you will see it to. Then make you decision on which direction you would like to take your tank in...cooler goldfish tank or more tropical community. You can’t have both (in the same tank)
Unfortunately for this fish if it is not moved into a tank alone or a goldfish only tank it will continually get picked on until it’s demise. Even if you do move it over and provide the best care for it he still might not make it. And that’s okay too, the only thing you can do is learn from your mistakes.
When we know better we do better.