Koi or nishikigoi (Japanese for coloured carp) originate from the paddy fields of Asia and Japan. Like most ornamental pond fish, koi were discovered quite by accident as coloured genetic mutations (accidents of nature) from native black carp which the farmers had introduced from Asia.
The carp were introduced into the paddy fields to supplement their bland diet. However, the carp bred naturally, producing many thousands of offspring, some of which were not black like their parents but pale yellow.
Over many generations, instead of being eaten, the cherished pale yellow koi were crossed with other similarly coloured genetic freaks. Different regions of Japan are reputed to have given rise to different koi varieties that are found in our ponds today.
The vast array of patterns and colours available today seems to be limitless as the pattern of each koi is unique. It is the knowledge that a truly excellent koi is irreplaceable that makes the top end of the market out of bounds financially for the majority of people. Nevertheless, one of the major attractions of keeping koi is that there will always be a wide selection of koi to choose from irrespective of your budget, be it a few pounds of spending money or a months salary.