Rainbow Fish Swimming Upside Down

HI everyone,

One of my two rainbow fish has been only swimming upside down as of the last few days. He alternates between swimming in circles and staying still. When he is staying still, he looks bent in the middle like a triangle, always unable to get himself right side up. I have attached a couple of screenshots from a video I took. Do you think my fish is injured or sick?

 

Hmm... are they bloated at all?

It sounds harsh but if they can't swim at all then there is little hope for them I'm afraid.

 

He does not appear bloated at all. I do not have any hope for him surviving either. I'm just curious about the cause of this as this came out of nowhere.

 

Any chance they had a head injury? Been bullied by other fish at all? Old maybe? Sometimes, Just like humans, the systems in fish just fail.

I think the best thing to do would be to euthanize them mix one drop of clove oil for ~50 drops of water, just an approximation, and put them in it. It's the best way to go, and better than floating listlessly in the main tank. I'm so sorry

 

I have two rainbow fish, and one has been mercilessly attacking the other for a few months now. These fish have never been aggressive in the few years I've had them except in the last few months, and it was only one of the fish that was aggressive; the bullied fish would never even defend himself. However, I believe that the aggressor is the one that is sick/injured here. The bullied fish always acted normal, whereas the bully would alternate between savagely attacking his brother and swimming wildly, either in circles or with frantic bursts across the tank. The healthy rainbow fish has not shown any of these signs. I feel like this ailment that my fish is going through has something to do with his sudden change of behavior.

 

Hmm... sounds like something wrong with their brain causing drastic behaviour changes. Maybe they had a head fungus/parasites of sorts? Anything look wrong with their head? Could just be trauma as well.

 

If this was the case then why wouldn't both of the fishes' behavior change?

 

Oh, it might still be contagious. You should quarantine the poorly rainbow if you can.