Glowlight Tetra Swimming Upside Down

[fish_tank0311]

Help!! This is the first time if had any problems with my 6 glowlight tetras, its a female one because its stomach is real fat (not dropsy fat) and all of a sudden i woke up, turn on the lights and he is swimming upside down, and his back looks like bent half way through, so it looks like a deformity like as if he was born like that but he is several months old and fully grown, and he has been doing this for about 24 hours now, because i wasnt sure what he was up to so i thought id leave it, but hes still going! Im posting this at 9:37 pm, so im going to go to sleep now (im 13 so early bed time ) but i hope he lasts till i can help him. I have put some tonic salt in, as thats a general disease curer and can reduce stress (so i have been told) What do i do? I have just fed them and he didnt get any food, but hes always in the bottom third of my tank so he doesnt get the floating flakes. What do i do? and how has he done this??? The only possible way i can see is he swam so hard and smashed himself on the glass and like broke his backbone or something but when i think about that, im just thinking "W...T...F??" What do i do?

 

[WILDER]

Has the curved spine be caused by another fish attacking it.
Or got stuck in an ornament.
What does it look like when your fish go to the toilet.
is the anus enlarged, or red and inflamed.
Do any fish look skinny,.
Any fish have sunken in bellys.

Is it possible to isolate the sick fish?

 

[fish_tank0311]

Has the curved spine be caused by another fish attacking it. No i dont believe so iv only got wee tetras in the tank
Or got stuck in an ornament. no i only have plants, and a tiny little "no fishing" ornament in the corner but they cant get stuck in that
What does it look like when your fish go to the toilet. i havent seen the fish go poo yet, i will observe later on tonight after i feed them and then get back to you
is the anus enlarged, or red and inflamed. nope his butt looks normal
Do any fish look skinny, no none skinny, just some neons have dropsy, but it seems theres ALWAYS 1 or 2 which have it in my tank, and no matter what i do i cant cure the dropsy, so im just taking as much care as possible and doing the tank maintaining, and have salt in the water.
Any fish have sunken in bellys. Nope

Is it possible to isolate the sick fish? well i have a breeding trap, which i can put him in, but other than that no.