Fish with curved spine?
Got back from a week-long Christmas vacation late last night, so didn't pay much attention to the fish until today. I notice one of the fish isn't keeping up with the others, and am wondering what might be the problem.
The tank is a moderately planted 30 gal, light to moderate stocking- 6 bloodfin tetra, 2 cory habrosus, 1 oto, a few snails and cherry shrimp. Low tech tank, due for a water change. Its approximately half well water, half RO water. Its dry, so the tank is topped off with 1-2 gals of RO water each week.
There appears to only be one fish affected. It is one of the bloodfin tetras. It no longer swims with the others. They like to hide in the lower foliage, this fish tends to swim near the top of the water and hide up there. It is definitely not swimming as fast, nor as "sleek" in the water- rather than darting forward, there is a lot of "wiggling" back and forth, especially of his tail end. His spine is curved downward rather than straight, and the tail end appears thinner (skinnier) than the other fish.
I'm wondering if it might be wasting disease? Any other thoughts? I'm particularly interested in if it is contagious.
One pic attached- hopefully it comes through okay.