Janet wrote:

Any self respecting koikichi will tell you that koi are not closely
related to goldfish....

For heavens sake, then they'd be wrong. No amount of breeding changes the
relationship. See
http://www.itis.usda.gov/servlet/Sin...h_value=163342

Koi are "common carp", Cyprinus carpio
Goldfish are Carassius Auratus
Both belong to the family Cyprinidae

Any koikichi will tell you there is a huge difference between koi making
it though a winter in an unheated pond and koi doing well or even thriving
over the winter... Have you read any of Peter Waddington's work

Yes. It would all depend on how well you _want_ them to do. If I'm trying
to raise a show quality meter-long koi, I'd treat it a darn sight better
than if I am trying to keep half-a-dozen mutt koi. They thrived. They
didn't become beauties, and I'll freely admit they might not even have
looked quite as good in the spring as they did in the fall, but by June
they were in fine shape. There are people here who are raising
show-quality koi, and they have different needs, but most of us are just
keeping ponds.
--
derek