My fish is hunchbacked!?

I have this zebra damio who has become hunchback. Im not really for certain why. I looked up stuff on fish becomming hunchback and ended up finding stuff on TB. I dont really think its TB though. My fish hasnt lost any weight, the color is still as good as it was when i bought it, there is no leasions or loss of apetite, or ay problems breathing. I dont know what it is.