Can either koi or shubunkin goldfish mate with plecostomus?

[koiguy1969]

piecos can survive down to 50*f ...they like the 70*s...but apparently can easily take the 50s... i know this because i have a pieco. and yes he winters indoors in my 800 gal wintering pond with my koi...hes over 5 years old and 20" long...healthy and active in my basement pond which is kept in the 50s. he spends 6 months a year there. i had 2 of them, but one got his head sucked on the end off a pump input hose that came off a prefilter, unbekownced to me and died. that one was 4 years old!