The Butterfly Fin Koi is reported to be more hardy than the standard
fin. This is based on genetics with what is called hybrid vigor (heterosis). The
Butterfly and Standard fin will inter-breed easily. The Butterfly have beautiful pectoral, ventral, dorsal, and
caudal fins that are long, flowing and almost featherlike in appearance.
They are truly the most beautiful Koi because of their fins. They come in
exactly the same colors, scale patterns, and metallics as standard fin Koi, and
have the same names.
They are truly what the Chinese describe as "swimming flowers", and
the Japanese as "living jewels".

Butterfly Koi view from the side -
Click to Enlarge
Butterfly Koi view from the top ready for
shipment
Our intelligent Butterfly Koi watching TV
The Butterfly Koi breeding program originated in the United States in the early 1980's.
At that time, Wyatt Lefever
obtained some unusual long-finned hybrid Asian carp. He started a breeding program
crossing them with metallic colored Koi resulting in "Butterfly Koi".
Butterfly (long-finned) Koi are not only beautiful with long flowing fins, but they are
quite hardy and able to withstand colder temperatures better than many traditional Koi.