Koi types are recognized by color, patterning, and also scalation. Most of the main colors are white, black, red, yellow, blue, and cream. Even though the possible colors are nearly unlimited, breeders have determined and called numerous specific categories. The well-known category is Gosanke, that is composed of the Kohaku, Taisho Sanshoku, and Showa Sanshoku varieties.
New koi types continue to be definitely developed. Ghost koi developed in the 1980s have become popular in England; they’re a crossbreed of wild carp and Ogon koi, and so are known by their metallic scales. Butterfly Koi (also called longfin koi, or dragon carp), also developed in the 1980s, are well known with their long and flowing fins. They’re hybrids of koi with Asian carp. Butterfly koi and ghost koi are believed by some to be not true Nishikigoi.
Types of Koi fish
- Kōhaku (紅白) is a white-skinned koi, with large red markings on the top. The name means “red and white”; Kohaku was the first ornamental variety to be established in Japan (late 19th century). Japan has got a lot of pride within the careful breeding of Koi Fish to make various fantastic colors and also patterns that are offered today.
- Taishō Sanshoku (or Taisho Sanke) (大正三色) is very similar to the Kohaku, except for the addition of small black markings called sumi (墨). This variety was first exhibited in 1914 by the koi breeder Gonzo Hiroi, during the reign of the Taisho Emperor. In America, the name is often abbreviated to just “Sanke”. The kanji, 三色, may be read as either sanshoku or as sanke.
- Shōwa Sanshoku (or Showa Sanke) (昭和三色) is a black koi with red and white markings. (The difference between the Sanke and the Showa is that the Sanke has a white base with red and black markings while the showa has a black base with red and white markings. ) The Sanke has predominately white fins where the Showa will have black in the fins. The Showa will have black on the head. It is often difficult to see the difference between Kindai Showa(Modern Showa) which have much more white and looks almost like a Sanke.
- Tanchō (丹頂) is any koi with a solitary red patch on its head. The fish may be a Tancho Showa, Tancho Sanke, or even Tancho Goshiki. It is named for the Japanese crane (Grus japonensis), which also has a red spot on its head same as Japanese flag. Most common are “Tancho Kohaku (all-white Koi with Tancho),” “Tancho Sanshoku (white Koi with Sumi similar to Shiro Bekko, and with Tancho),” and “Tancho Showa (Showa Sanshoku without red markings except for Tancho),” etc. However, “Tancho Goshiki (Koi of five colors with Tancho),” and “Tancho Hariwake” are rare
- Chagoi (茶鯉), “tea-colored”, this koi can range in color from pale olive-drab green or brown to copper or bronze and more recently, darker, subdued orange shades. Famous for its docile, friendly personality and large size, it is considered a sign of good luck among koi keepers. Chagoi also must have the potential to attain jumbo size, that is over 30 inches while meeting all the above criteria isn’t that easily found.
- Asagi (浅葱) koi is light blue above and usually red below, but also occasionally pale yellow or cream, generally below the lateral line and on the cheeks. Asagi koi is regarded as the oldest kinds of Koi Fish and it has provided the basis for a lot of subsequent varieties. Its back is covered in a net-like reticulated scale pattern of indigo, navy blue or pale blue.
- Utsurimono (写り者) is a black koi with a white, red, or yellow markings, in a zebra colour pattern. Shiro Utsuri – A black Koi with white pattern
Hi Utsuri – A black Koi with red pattern
Ki Utsuri – A black Koi with yellow pattern
- Bekko (鼈甲) is a white-, red-, or yellow-skinned koi with black markings sumi (墨). The Japanese name means “tortoiseshell,” and is commonly written as べっ甲. There are three varieties of Bekko. Shiro Bekko (white with black spots), Ki Bekko (yellow with black spots) and Aka (red/orange with black spots). It may be confused with the Utsuri. The sumi (black) markings of a bekko must be deep, solid, and shiny lacquer-black.
- Goshiki (五色) is a dark koi with red (Kohaku style) hi pattern. The Japanese name means “five colors” originally an Asagi x Sanke cross. It appears similar to an Asagi, with little or no hi below the lateral line and a Kohaku Hipattern over reticulated (fishnet pattern) scales. The base color can range from nearly black to very pale, sky blue. For Goshiki koi, They are looking better when in warm water as their colors darken in cold water.
- Shūsui (秋翠) means “autumn green”; by crossing Japanese Asagi with German mirror carp. The fish has no scales, except for a single line of large mirror scales dorsally, extending from head to tail. The most common type of Shūsui has a pale, sky-blue/gray color above the lateral line and red or orange (and very, very rarely bright yellow) below the lateral line and on the cheeks.
- Kinginrin (金銀鱗) is a koi with metallic (glittering, metal-flake-appearing) scales. The name translates into English as “gold and silver scales”; it is often abbreviated to Ginrin. There are Ginrin versions of almost all other varieties of koi, and they are fashionable. Their sparkling, glittering scales contast to the smooth, even, metallic skin and scales seen in the Ogon varieties. Recently, these characteristics have been combined to create the new ginrin Ogon varieties.
- Ōgon (黄金) is a metallic koi of one color only (hikarimono 光者). The most commonly encountered colors are gold, platinum, and orange. Cream specimens are very rare. Ogon competes in theKawarimono category and the Japanese name means “gold.” Recently, the metallic-skinned Ogon is being crossed with ginrin-scaled fish to create the ginrin Ogon with metallic skin and sparkling (metal flake) scales.
- Kumonryū (九紋竜) （literally “nine tattooed dragons”） is a black doitsu-scaled fish with curling white markings. The patterns are thought to be reminiscent of Japanese ink paintings of dragons. They famously change colour with the seasons. Kumonryu competes in the Kawarimono category.
- Ochiba (落葉) is a light blue/gray koi with copper, bronze, or yellow (Kohaku-style) pattern, reminiscent of autumn leaves on water. The Japanese name means “fallen leaves”.
- Koromo (衣) is a white fish with a Kohaku-style pattern with blue or black-edged scales only over the hi pattern. This variety first arose in the 1950s as a cross between a Kohaku and anAsagi. The most commonly encountered Koromo is an Ai Goromo, which is coloured like a Kohaku, except each of the scales within the red patches has a blue or black edge to it. Less common is the Budo-Goromo, which has a darker (burgundy) hi overlay that gives it the appearance of bunches of grapes. Very rarely seen is the Tsumi-Goromo which is similar to Budo-Goromo, but the hi pattern is such a dark burgundy that it appears nearly black. Similar to Kohaku, but with accents of blue, black, purple mixed in with some to much of the red, due to cross-breeding with Asagi.
- Hikari-moyomono (光模樣者) is a koi with coloured markings over a metallic base or in two metallic colours.
- Kikokuryū（輝黒竜, literally “sparkle” or “glitter black dragon”）is a metallic-skinned version of the Kumonryu.
- Kin-Kikokuryū （金輝黒竜, literally “gold sparkle black dragon” or “gold glitter black dragon”）is a metallic-skinned version of the Kumonryu with a Kohaku-style hi pattern developed by Mr. Seiki Igarashi of Ojiya City. There are (at least) six different genetic subvarieties of this general variety.
- Ghost koi（人面魚、じんめんぎょ, a hybrid of Ogon and wild carp with metallic scales, is considered by some to be not nishikigoi.
- Butterfly koi（鰭長錦鯉、ひれながにしきごい） is a hybrid of koi and Asian carp with long flowing fins. Various colorations depend on the koi stock used to cross. It also is considered by some to not be nishikigoi.
- Doitsu-goi (ドイツ鯉) originated by crossbreeding numerous different established varieties with “scaleless” German carp (generally, fish with only a single line of scales along each side of the dorsal fin). Also written as 独逸鯉, there are four main types of Doitsu scale patterns. The most common type (referred to above) has a row of scales beginning at the front of the dorsal fin and ending at the end of the dorsal fin (along both sides of the fin). The second type has a row of scales beginning where the head meets the shoulder and running the entire length of the fish (along both sides). The third type is the same as the second, with the addition of a line of (often quite large) scales running along the lateral line (along the side) of the fish, also referred to as “mirror koi”. The fourth (and rarest) type is referred to as “armor koi” and are completely (or nearly) covered with very large scales that resemble plates of armor. They also are called Kagami-goi（鏡鯉、カガミゴイ, or mirror carp（ミラーカープ）.
- Kawarimono (変わり者) is a “catch-all” term for koi that cannot be put into one of the other categories. This is a competition category, and many new varieties of koi compete in this one category. It is also known as kawarigoi (変わり鯉).