Koi Varieties and Classification: Gosanke and Beyond

Origin of nishikigoi in Niigata and the classical variety groups: Kohaku, Sanke, Showa, Utsurimono, Bekko, Asagi, Shusui, Koromo, Hikarimono, Kinginrin, Tancho, Doitsu, Kawarimono.

Origin in Niigata

Koi, or nishikigoi ("brocaded carp"), are ornamental forms of the Amur carp, Cyprinus rubrofuscus, an East Asian species distinct from the European common carp. According to Wikipedia, systematic breeding of coloured carp began in the 1820s in the Nijūmuragō area (present-day Ojiya and Yamakoshi, Niigata Prefecture). Red-and-white fish were produced during the Bunka and Bunsei eras (1804–1830), and by around 1875 coloured carp had become popular. Tropical Fish Hobbyist notes that the ancestors were food carp whose colour mutations were selectively bred in the early 1800s.

The name nishikigoi dates from the 1910s; earlier names were madaragoi (spotted carp) and kawarigoi (variant carp). Wikipedia attributes it to Kei Abe, chief fisheries officer of Niigata in the Taisho era. The turning point was the Tokyo Taisho Exposition of 1914, where an exhibit by Niigata breeders won a silver medal and eight fish were presented to the Crown Prince. Kohaku and Taisho Sanshoku were fixed as varieties in 1917 and Showa Sanshoku in 1927; koi were shown in San Francisco in 1939.

How varieties are classified

Koi varieties are defined by colour, pattern and scale type rather than body shape. Wikipedia cites Zen Nippon Airinkai, a leading Japanese koi organisation, as recognising more than 100 varieties in 16 classes. The terms hi (red), shiroji (white ground) and sumi (black) recur throughout. Kohaku, Taisho Sanke and Showa Sanshoku are collectively called Gosanke ("three families"), the "big three" of Practical Fishkeeping; the other classes group fish by a shared trait such as a black base, a blue back, a metallic skin or glittering scales.

Gosanke: Kohaku, Sanke and Showa

Kohaku

A white body with large red markings, and one of the first varieties fixed in Japan. Wikipedia records that in 1888 Kunizo Hiroi bred a red-headed female with one of his males, founding the now-extinct Gosuke bloodline; Tomoin and Yagozen remain the major bloodlines. Pattern terms include nidan, sandan and yondan for two-, three- and four-step patterns, inazuma for a lightning zigzag, and bozu for a fish without a head marking, a fault. Judging calls for bright, even red with sharp edges and an obligatory head marking; Practical Fishkeeping lists snow-white skin, deep red and a balanced pattern as quality indicators.

Taisho Sanke

Taisho Sanke, or Taisho Sanshoku ("three colours"), resembles Kohaku with the addition of small black sumi markings, which Practical Fishkeeping describes as a stepping-stone pattern along the body. Wikipedia states it was first exhibited in 1914 by the breeder Gonzo Hiroi during the Taisho reign, from which it takes its name.

Showa Sanshoku

Showa has a black base with red and white markings and was first exhibited in 1927. Wikipedia credits Jukichi Hoshino with the original pairing of a Kohaku and a Ki Utsuri; early fish had greyish white, dull black and weak red, later improved by outcrossing to Kohaku. Motoguro denotes black at the base of the pectoral fins. According to Practical Fishkeeping, the key difference from Sanke is that on a Showa the black wraps around the body below the lateral line and appears on the head. Modern Kindai Showa carry more white and can be hard to tell from a Sanke (Wikipedia).

Black-based and tortoiseshell groups: Utsurimono and Bekko

Utsurimono are black koi with white, red or yellow markings; utsuri means "to print", the black being likened to ink stains, and Wikipedia describes them as Showa lacking one pigment. Practical Fishkeeping nicknames Shiro Utsuri the "panda" koi and Hi Utsuri the "tiger" koi; Ki Utsuri carries yellow. Bekko, named for tortoiseshell, are white-, red- or yellow-skinned fish with black sumi markings (Shiro, Aka and Ki Bekko) and can be confused with Utsuri (Wikipedia).

Blue-backed and reticulated groups: Asagi, Shusui, Koromo and Goshiki

Asagi is one of the oldest varieties: light blue above the lateral line, red (occasionally yellow or cream) below it and on the cheeks. Shusui ("autumn green") was created in 1910 by Yoshigoro Akiyama by crossing Asagi with German mirror carp; it is pale blue-grey above, red or orange below, with scales only along the dorsal line. Koromo is a white fish with a Kohaku-type red pattern in which each scale within the red carries a blue or black edge (Ai Goromo); it arose in the 1950s from Kohaku crossed with Asagi. Goshiki ("five colours") combines a Kohaku-type red pattern with reticulated, net-like scales over a base from nearly black to pale sky blue (Wikipedia).

Metallic and glittering koi: Hikarimono and Kinginrin

Ogon is a single-coloured metallic koi whose name means "gold"; gold, platinum and orange forms are common, and Wikipedia records that Sawata Aoki created it in 1946 from wild carp caught in 1921. Metallic koi form three show groups: Hikarimujimono (solid metallic, such as the yellow Yamabuki Ogon), Hikarimoyomono (coloured markings over a metallic base, such as Hariwake and Kujaku, both described by Practical Fishkeeping) and Hikari Utsurimono (Utsurimono crossed with Ogon). Kinginrin, or Ginrin, denotes glittering reflective scales; Wikipedia notes that Ginrin versions of almost every variety occur.

Tancho, Doitsu and Kawarimono

Tancho is any koi with a solitary red patch on the head, named for the red-crowned crane Grus japonensis; Practical Fishkeeping describes the ideal Tancho Kohaku as a round spot centred on the head, and Tancho Sanke, Showa and Goshiki also exist. Doitsu koi descend from crosses with German "scaleless" carp and typically carry a line of scales beside the dorsal fin; Wikipedia lists four scale patterns and gives kagami-goi (mirror carp) as a synonym. Kawarimono is the catch-all class for koi that fit no other group and the class for new varieties. It includes Chagoi ("tea-coloured", olive to bronze; fast-growing and tame according to Practical Fishkeeping), Ochiba ("fallen leaves", blue-grey with a copper or yellow pattern) and Kumonryu (a black Doitsu fish with curling white markings that change with the seasons).

Longfin and ghost koi

Butterfly or longfin koi were developed in Japan in the 1980s; Wikipedia records that the Saitama Prefectural Fisheries Experiment Station began the breeding in 1980 using a long-finned Indonesian carp. Their fin-to-body ratio far exceeds nishikigoi standards, and Zen Nippon Airinkai has long excluded them from judging. Ghost koi, a hybrid of Ogon and wild carp with metallic scales, are likewise not regarded by some as nishikigoi.

Size, growth and lifespan

Tropical Fish Hobbyist gives an adult size of up to 3 ft (about 90 cm) and 40 lb (about 18 kg), growth of 6–7 in (15–18 cm) a year in the first two years, and a lifespan of over 30 to 40 years. Wikipedia reports claims of 100–200 years, including a koi named Hanako whose scale rings were read in 1974 as 226 years; these are reported claims, not routine expectations. Most offspring even of champion parents are culled as unacceptable nishikigoi (Wikipedia). Spawning and fry raising are covered in the separate breeding guides for Kohaku, Sanke, Showa, Asagi, Bekko, Tancho, Ginrin, Doitsu and butterfly koi.