ryukins question

Hi everyone.

I have one red ryukin who has just started to develop his 'hump'
He has started to swim a bit funny, or wobbly. none of the other fish have
any problems, and never have done, and I water change and check parimiters
every week and never had any problams with them.

What I want to know is, when the ryukin starts to develop do their swimming
look more wobbly? he doesnt float, or sink or swim on his side and seems
quite happy, jusy when he swims he sort of wobbles left to right.

Is there a possibilty this is swim bladder or is it normal?

thanks in advance
Kellie