Lyretail molly problem with spine

[twoodrough]

The fish's back seems to be bending. I have been feeding a bit more so his belly is bigger and seems to stick out one side more than the other. His head seems to be permanantly turned to the right now. He was not like this before. Is it because of the bigger belly? Or is this something that happens to molly's?

 

[joemamauggly]

pictures please

 

[Borderlesscott]

Try adding salt, if not already added. Good article on Sailfin care - http://www.tfhmagazine.com/blogs/2012/11/21/tfh-classic-salt-and-other-sailfin-secrets/