Skeletal deformities / kinked spine
1) Electrical shock. Faulty electrics or lightening strike
2) Use of organophosphates
3) Nutritional imbalance
4) Genetic abnormalities
5) Muscular damage / physical damage
6) Toxins
Unless there is an obvious known problem, it is difficult to establish the cause. A radiograph (sort of x-ray) would assist for skeletal problems
Loss of equilibrium with fish unable to stay upright. Fish may be able to maintain position when swimming, but turn over when they stop swimming.
1) Swim-bladder disorder / disease caused by viral or bacterial infection, constipation (mainly fancy goldfish) or other organ disease.
2) Internal organ disease, i.e. kidney / intestinal disease or blockage. Usually only established at post mortem
Sorry due thats all I can find on the symptoms you described
I hope it gets better
