Koi (English /ˈkɔɪ/, Japanese:koi or more specifically nishikigoi , literally "brocaded carp"), are ornamental varieties of domesticated common carp (Cyprinus carpio) that are kept for decorative purposes in outdoor koi ponds or water gardens.
Koi varieties are distinguished by coloration, patterning, and scalation. Some of the major colors are white, black, red, yellow, blue, and cream. The most popular category of koi is the Gosanke, which is made up of the Kohaku, Taisho Sanshoku, and Showa Sanshoku varieties.
The word koi comes from Japanese, simply meaning "carp." It includes both the dull grey fish and the brightly colored varieties. What are known as koi in English are referred to more specifically as nishikigoi in Japan (literally meaning "brocaded carp"). In Japanese, koi is a homophone for another word that means "affection" or "love"; koi are therefore symbols of love and friendship in Japan.
History:
Carp are a large group of fish originally found in Central Europe and Asia. Various carp species were originally domesticated in East Asia, where they were used as food fish. Carp are coldwater fish, and their ability to survive and adapt to many climates and water conditions allowed the domesticated species to be propagated to many new locations, including Japan. Natural color mutations of these carp would have occurred across all populations. Carp were first bred for color mutations in China more than a thousand years ago, where selective breeding of the Prussian carp (Carassius gibelio) led to the development of the goldfish.
The common carp was aquacultured as a food fish at least as far back as the fifth century BC in China, and in the Roman Empire during the spread of Christianity in Europe.[3] Common carp were bred for color in Japan in the 1820s, initially in the town of Ojiya in the Niigata prefecture on the northeastern coast of Honshu island. By the 20th century, a number of color patterns had been established, most notably the red-and-white Kohaku. The outside world was not aware of the development of color variations in koi until 1914, when the Niigata koi were exhibited in the annual exposition inTokyo. At that point, interest in koi exploded throughout Japan. The hobby of keeping koi eventually spread worldwide. They are now commonly sold in most pet stores, with higher-quality fish available from specialist dealers, including some who offer next-day delivery on koi purchases online.
Extensive hybridization between different populations has muddled the historical zoogeography of the common carp. However, scientific consensus is that there are at least two subspecies of the common carp, one from Western Eurasia (Cyprinus carpio carpio) and another from East Asia (Cyprinus carpio haematopterus). One recent study on the mitochondrial DNA of various common carp indicate that koi are of the East Asian subspecies. However, another recent study on the mitochondrial DNA of koi have found that koi are descended from multiple lineages of common carp from both Western Eurasian and East Asian varieties. This could be the result of koi being bred from a mix of East Asian and Western Eurasian carp varieties, or being bred exclusively from East Asian varieties and being subsequently hybridized with Western Eurasian varieties (the butterfly koi is one known product of such a cross). Which is true has not been resolved.
It was from this handful of Koi breeds that all other Nishikigoi types were bred, with the exception of the Ogon variety (single colored, metallic Koi) which wasn't developed until recently. The last development of this early time was a great breakthrough in Koi breeding and is still revered as one of the most traditional of Koi breeds. A tri-colored Koi called a Taisho Sanshoku, more commonly known as the Sanke, was first seen during the Meiji era (1868-1912). Though it is not known who first developed this breed, the Sanke was exhibited for the first time in 1915, when the Koi was about 15 years old.
thanks to: http://en.wikipedia.org/wiki/Koi
