The few that I have caught: Some have barbels, some do not.
From what I have been reading, Koi and Goldfish can cross, and it happens often enough to be "common", but they cannot reproduce. If I can confirm they are crosses, some are going in the farm pond. Not going to unless I am certain.

An overcrowded garden pond is sure doom for them in the winter.

I ordered a large koi basket net. I needed to drain down the pond to patch a small hole, and to install an underground line between the basement and pond for air so it doesn't freeze shut in the winter. Any exposed airline gets condensation, and ices closed.