Nishikigoi Breeding, Hobbyists, and Shows
Nishikigoi carp have been bred in Ojiya since the 1800s and are an important part of the town’s heritage. Koi farms and breeding techniques have been passed down for generations. Auctions take place from autumn to spring, drawing koi collectors from around the world. Breeders from all over Japan gather at annual nishikigoi shows, entering their most beautiful specimens for the chance to be declared “Grand Champion.”
Breeding nishikigoi
A large number of Japan’s nishikigoi breeders are based in the mountainous areas around Ojiya, where they raise the fish in terraced ponds. Throughout the spawning season, which lasts between April and early July, breeders carefully select koi to mate. Lineage and physical traits, such as brightness of color and body shape are among the factors that influence the matchmaking process. Once the fry are born, those with the most vivid and distinct patterns are selected and raised at the farm for eventual sale.
Water and soil quality play a vital role in raising healthy koi. The abundant snowmelt from the mountains around Ojiya supplies the ponds with fresh, clean groundwater, rich in minerals. Years of experience and observation have led farmers in the region to conclude that the type of soil in which ponds are dug plays a role in the healthy development of different varieties of koi. For instance, breeders believe that the multicolored Showa Sanshoku variety is suited to ponds dug in sandy soil, and that the red-and-white Kohaku thrives in clay-rich soil.
Koi reach a suitable size for sale in September the year they are born, and reach adulthood after two to four years. Auctions take place from autumn to spring in Ojiya and other nishikigoi hubs around Japan, such as Aichi and Hiroshima prefectures.
Ojiya’s nishikigoi fishery cooperative is made up of about 60 breeders, and the majority of the koi they raise are exported overseas.
Keeping nishikigoi as a hobby
In the 1960s, keeping nishikigoi gained widespread popularity in Japan, and began to be admired overseas. The development of modern shipping technology has made it easier to safely ship the carp over long distances, and the number of nishikigoi hobbyists around the world continues to grow. Koi adapt well to a variety of environments and can live for 30 to 40 years.
Showcasing Japan’s living jewels
Nishikigoi shows have been held annually around Japan from as early as 1912. These shows are an opportunity for breeders to showcase their most exceptional carp. The shows bring together koi enthusiasts and breeders from all over the world, during which the entries are appraised for their colors, shine, patterns, and numerous other traits. The shape of their body is particularly important—prize-winning nishikigoi tend to have spindle-shaped bodies with well-developed muscles along the spine.
The All Japan Nishikigoi Show, usually held in Tokyo, is considered one of the most prestigious. At the inaugural show in 1968, nishikigoi were dubbed Japan’s national fish. Since then, the show has been held annually in January, typically featuring around 1,900 fish. Other notable shows include the Zen Nippon Airinkai, held in November (the venue changes every year), and the All Japan Junior Koi Show, held in Niigata in April.