The province of Niigata, famous for its mountainous landscapes, became the place where the first mutations in the color of the carp appeared. What was the reason for this? According to one version, this could be facilitated by a constant, but not strong, radiation background, often present in areas with a large number of mountain faults. According to another – the complete absence of light under the ice in the winter season – the thickness of the snow cover in Niigata can reach 4-5 meters.
It snows there every day in winter. One way or another, the first changes in the color of the fish began to appear. At first, these were carps of an unsystematized color, but then, as a result of careful selection, the first koi breeds began to appear, or rather nishikigoi, which means “brocade fish” in Japanese, i.e. fish with a pattern similar to patterned fabric. Now the words “koi” and “nishikigoi” are almost identical in meaning.
Koi carp are able to live for several decades, and some individuals even centuries. So, a purple koi named Hanako lived with several owners. Hanako’s age, which reached 226 years old, was determined by one of her scales and is still one of the longest-lived koi in the world.
The advent of koi
Koi are domesticated ornamental carps that are a subspecies of the common carp (Cyprinus carpio). The name itself in Japanese means carp. About two thousand years ago, black-colored carps were brought to China from the Caspian coast of Iran.
In China, they began to be bred in ponds for further use for culinary purposes and as formidable eaters of pesky insects. They were brought to Japan by Chinese settlers in the 14th century.
The most widespread breeding of black carps was in the Japanese province of Niigata on the island of Honshu, where increased seismic activity and poor soil hampered the development of agriculture.
In many mountainous areas, these fish have long been the main food of the local population.
For unknown reasons, it was here that in the period from 1804 to 1830 a chromatic mutation occurred among them, as a result of which individuals with red, white and yellow colors appeared.
Over the next twenty years, after crossing red and white carps, a new breed appeared, which the Japanese called kogaku (red and white). It was the first true koi to bear the colors of the national flag of Japan.
There was a red spot on the back of the white fish, smoothly passing to its head.
The most valued and valued individuals with a perfect round spot on the head. They are called tancho-kogaku and are the symbol of Japan, along with the Japanese crane, which has a similar reddish cap. The size of such beauties can exceed 1 m.
Already by the beginning of the 1870s, fish with an unusual color became the decoration of many private ponds of the Japanese nobility and settled in ponds at Shinto shrines. At an agricultural exhibition in Tokyo in 1914, the mayor of a village in the province of Niigata presented 27 koi to the public, which appealed to visitors, making a special impression on representatives of the United States and Europe.
The most beautiful of them were presented to the daughter of Emperor Taisho. This event made it into the gossip column and served as an excellent advertisement for the distribution of koi in the domestic market.
From the fun of aristocrats, breeding a new breed soon turned into a profitable business. It brought especially significant income after the end of the Second World War, thanks to the availability of transport aviation. Koi began to be supplied to moneybags in other countries.
Currently, Japanese entrepreneurs sell several billion dollars worth of koi every year.
They are also bred in other countries, but mostly as fish for elite restaurants or for not too demanding aquarists.
Now there are at least 16 main breeds of koi carp, which in turn are divided into several dozen varieties.
The most popular of these are taise sanko (with red and black spots on a white background), seva (red and white spots on a black background), utsurimono (white, red and yellow spots on a black background), bekko (black spots on a white, red or yellow background) and asagi (white-blue back with light blue spots, white head and red cheeks).
Sorting and content
Not every fish deserves to be called a koi. All fry undergo strict selection during sorting. A large number of small carps are rejected due to non-compliance with the standard. After going through at least a hundred sortings, units are selected from one litter.
The quality of a koi can be determined if the fish have reached a size of about 30 cm.
After that, they are divided into categories, the cost of which can vary significantly. It takes more than 30 years to develop a new breed.
To keep this fish does not require special conditions. Koi are unpretentious, undemanding to food and very quickly get used to people. It should be remembered that they feel good in spacious waters. Carp does not tolerate winter cold, so it must be moved to a warm room or provide local water heating with stable aeration.
There is an opinion that koi carp can only be kept in a pond, as they look more beautiful when viewed from above. Special breeds (naked and mirrored) have already been bred, which are best observed in an aquarium.