Jim . . .
Playing with fish beats chopping wood -- any day!
Interesting thread and thanks for sharing.
I recognize your male as the one that won Best in Size 3 at the 2005 Koi Kichi Show. Beautiful koi. He's gained some volume, but I'm sorry to hear he's only reached 18" in length.
As for shimmies -- been there, done that and got my own photos to prove it.