The exact time of origin of Koi isn’t entirely clear, but these pond fish have become a source of beauty throughout the world. It is said the Koi originated in areas around China, several hundred years BC, but there are also accounts of the black carp originating in areas around Iran rather than China. The original fish were a gray-black wild carp, which are referred to as Magoi. The base stock pond fish for Koi did not originate in Japan, rather the black carp were first introduced in Japan during and after conflicts with China as it invaded Japan. As time passed into the 17th century, Japanese farmers in one particular area of Japan started keeping these Magoi in the irrigation areas of their farms as a source of food.
Color variations in koi started to appear in the early 1800s, and the more formal name for Koi is Nishikigoi, which translates loosely to “colored Carp.” These color variations were primarily red, white, and yellow and they were beginning to be bred and cross bred for their colors by the mid 1800s. Koi breeding for color was only within a small area of Japan until the early-to-mid 1900s. At this time, Koi began to expand worldwide as transporting them around the world grew easier, especially with the invention of the plastic bag, which made shipping fish to faraway destinations possible.
Today, there are over 100 color varieties of Koi bred throughout the world as pond fish, and there are also less traditional koi available, such as a long fin variety that originated in a different part of Asia. The names of some common Koi varieties are Showa, Kohaku, Ogon, Sanke, and Matsuba, but there are even variations within those names such as Platinum Ogon and Yamabuki Ogon, which indicate differences in color.
Koi bred and raised in the United States tend to live 40 to 70 years, while Koi bred and raised in Japan tend to live longer, with the record-holding koi “Hanako” living to 226 years old. Other fish that were living in the same pond as Hanako were over 100 years old. Much like large parrots, koi are sometimes passed from one generation to the next in a will, because they can outlive their owners.