Furcata rainbowfish suddenly showing very bent spine

[mkpeppermint]

I've had these furcata rainbow fish for most of the year. I haven't introduced any new plants or livestock to this tank for at least a month or longer. Suddenly I noticed one of them has a curved spine. No other fish in the community tank show any symptoms. Could it be anything else besides Fish TB?

In the case that it is fish TB, should I treat my main tank with antibiotics as well as the quarantined fish? Thank you!

 

[DeepAsHadal]

This web page mentions TB causes a humpback, this curve would be noteable looking at from the side. Maybe someone here can help.
https://aquariumscience.org/index.php/11-9-spinal-deformities/
https://aquariumscience.org/index.php/10-4-1-fish-tb-in-depth/

I overfed my betta and he ended up with swim bladder and spine S shape looking at him from the top. I'm more careful now. I'm not sure if rainbow fish are prone.

Are there any other symptoms?