Koi origins. What are they and where have they come from?

Koi is an abbreviation of nishikigoi, a general term given by the Japanese to coloured koi with markings which are bred for their ornamental value. Their origin can be traced as far back as 2500 years ago when the word koi was first used to describe the black ancestors of the beautifully coloured nishikigoi that we admire and keep in our ponds today.

Way back then, koi had no ornamental value, but were bred for food in China. These original koi (or carp) were black (called magoi) and the jewel-like nishikigoi that we are so fond of today remained hidden and ‘uncut’ within the genes of this unappealing food fish for over another 2 millennia. Magoi were introduced to Japan about 1000 years ago and were later to produce what are now regarded worldwide as living forms of Japanese art.

So how did such dull and unappealing fish spawn an aquatic cultural revolution?

Even though records show that the Persian carp were introduced to Japan over 1000 years ago, Nishikigoi first appeared a mere 160 years ago.

Niigata is a most mountainous and picturesque region of Japan which is recognised as the birth place of nishikigoi. Inhabited by relatively poor rice growers, the Niigata farmers had introduced magoi into their paddy fields as a supplementary source of food that would grow in their flooded rice fields with little extra effort.

The black carp, in true carp style, bred uncontrollably to regularly produce many thousands of fry, a small number of which caught the attention (an imagination) of the farmers on account of their unusually light colouration. A number of forward-thinking farmers either intentionally or by accident separated these coloured carp and nurtured them as pets in dedicated ponds. These fish bred with other coloured relatives to produce even more coloured carp in greater ratios than before. Nishikigoi were born.

In this respect, koi have something in common with other pond fish such as goldfish and shubunkins in that they too have descended from visually unappealing ancestors and their appearance is largely down to man’s selective breeding.

Such mutants or ‘mistakes of nature’ occur in any wild population of plants and animals. Rarely do the characteristics of these mutants make them suitable for their environment, soon dying which leads to the loss of the mutant genes. This is certainly true of koi, which if left in a ‘wild’ situation all those years ago without man’s intervention, would most certainly have been predated by birds in preference to the darker and better camouflaged natural carp.

Furthermore, if these mutants were allowed to breed with darker ‘wild koi’ then the attractive features would have been lost in the offspring. The rice farmers soon recognised this and ensured that coloured carp only bred with coloured carp and before long, specific features such as pattern and colour appeared in a number of offspring.

Japanese records accurately show when, and in most circumstances, by whom, the first koi varieties were created or discovered. In order to stabilise these desirable characteristics, koi farmers crossed closely related fish to produce high quality, well coloured offspring, and they continue to do so today.

Unfortunately, the koi we buy and keep in our garden ponds are these same in-bred fish, which are beautiful to look at but are also very delicate and susceptible to disease. This is why koi demand so much more care and attention over other pond fish.

Kill blanketweed and string algae.