Koi varieties explained: a comprehensive guide to recognising koi varieties
Koi remain one of the most lasting and popular varieties of fish for the discriminating aquarist. They are one of the few fish with records of keeping koi going back hundreds of years, though modern koi as we know them have been around for just over one hundred. Originally hailing from Japan’s Niigata prefecture, koi fish have become a staple fish for many aquarists.
So many koi, so little time
Any hobbyist with a passing interest in koi fish may have, at some point, asked themselves just how many varieties of koi fish exist in the world. This is a tough question to answer, since new species are developed every year. The current count uses thirteen separate classifications with more than a hundred individually named varieties.
Since there are enough individual varieties to fill an encyclopedia with, this article will represent each of those thirteen categories with their most popular fish. Some categories feature multiple koi worth mentioning. If you would like to delve deeper into the world of koi fish, there are great supplementary resources available, including high quality books with exhaustive lists of individual varieties.
The beginning Koi: Kohaku
Experts in the koi industry often claim that keeping koi begins and ends with Kohaku. It is believed to be the first ornamental koi variety.This deceptively simple white fish with red blotches is emblematic of the species, and may very well be the fish that comes to mind when you mention the word, “koi”.
Because of their simpler coloration, these koi are often recommended for beginners to the koi hobby. Interestingly, high quality specimens are also coveted by advanced koi keepers for their subtle patterns and elegant coloration. A high quality Kohaku koi features a snowy white complexion and a uniform red hue. Orange is common, but generally avoided in favor of a deeper crimson coloration.
Tancho Kohaku is a specific variety of this category that features a single bright red circle on the forehead, symbolizing the Japanese national flag. A koi with the tancho mark alongside other markings is called a Maruten Kohaku.
Show quality kohaku have very clearly defined edging to the red coloration, ie any blurring of the red into the white is penalised. Kohaku is still the most popular variety of koi in Japan.
The Taisho Sanshoku Koi: Sanke
Sanke koi are white based with red and black patches over the white. This particular variety enjoys a historical name alongside its common name. Taisho Sanshoku refers to the era and region from which this koi originates. Sanke koi look very similar to Kohaku koi except they have distinctive black markings in addition to their white and red coloration.
The best way to judge the quality of a Sanke koi is by first appealing to their Kohaku-like markings. Bright, snowy white and a deep, crimson red is ideal. After identifying these elements, you can examine the black spots, which should by an inky, pure black. Young sanke koi often have black spots that appear blue in hue; as the fish matures, this blue becomes a jet black shade in time.
The black koi: Showa
Showa koi are often confused with sanke koi, since they feature the same combination of white, red and black markings. The difference is that Showa koi are distinctively black-based, with additional white and red markings overlaying the black foundation.
High quality specimens are prized for the balance between the three colors. It is ideal for the showa koi to have a distinctive swath of black color that forks out from the base of the pectoral fins, making for a striking and powerful display of color.
Showa will have some black on its head whereas a sanke will not and good quality modern showas have more white than previously. Again, there should be no blurring. a sharp edge to the colours is preferred for show quality showas.
The fire and ash koi: Hi Utsuri = black with red
The Utsurimono family contains koi with a pattern containing two highly distinct colors. Of these, the most popular and visually striking is the Hi Utsuri black with red. It is easily recognizable by its black foundation and bright red markings. The two colors should offer a stark contrast, with the deeper hues being more prized than lighter shades.
Hi Utsuri are commonly sought out for unique asymmetric color patterns. Often, koi experts will recommend Utsurimono koi with the most quirky patterns possible, in order to emphasize their character. There is a yellow version with yellow markings over the black foundation – ki utsuri and a white version with white patches over the black – shiro utsuri.
The rock garden koi: Bekko
Shiro bekko koi are incredibly popular for their stark black-on-white coloration. Often confused with Shiro Utsuri, a white-on-black variety, these ones feature minimal black markings that should resemble the placement of small stones used in Japanese rock gardening against a white sand surface.
The ideal combination is a clean, snowy white with small specks of strong black overlying the koi’s scales. There should be no black on the koi’s head, or below the lateral line of the koi. A checkerboard pattern along the koi’s back is a sign of particular excellence.
There are two other main bekko types the aka bekko which is a red based fish black markings over it and the ki bekko which is a yellow based fish with black markings over it.
Show quality bekkos have distinct black markings without speckling and clearly defined edges to the black and the base colour should be snow white in the shiro bekko, crimson red for the aka bekko and a canary yellow for the ki bekko.
The single-color metallic koi: Hikarimuji
Hikarimuji koi feature a single shiny metallic color, with no other markings anywhere on the body. The best specimens feature a bright and metallic finish, highly prized for their reflective surface and beautiful metallic luster. The colour must be evenly spread over the whole body.
These fish come in all colors, from vibrant white to deep orange or yellow. The most consistent and bright the coloration is, the higher quality the koi.
Yamabuki Ogon – pure metallic yellow/gold. Platinum Ogon – pure metallic white/silver. Orange Ogon – pure metallic orange/copper. There are also the kin matsuba and gin matsuba which have raised metallic markings that look like pine needles, where the individual scales are seen.
The metallic koi: Hikarimoyo
These koi are similar to Hikarimuji koi, featuring the same metallic luster, but with multiple colors. This is a koi classification that features multiple individual types, such as the colorful Kujaku koi, also known as the peacock koi.
The key to determining the quality of these koi is in their metallic luster. Coloration is unique for each individual and generally takes second place in importance to a strong, shiny metallic tinge.
The autumn water koi: Shusui
This species of koi adds a fascinating character to any koi collection. Shusui is the scaleless version of the Doitsu Asagi. The Shusui should only have two rows of blue scales on its back and might have scales along its lateral line. The common name Shusui means, “autumn water” and is used to describe the unique double row of blue scales running down the length of the koi’s back. On each side of the body there are vibrant red markings.
The scalelessness gives a smooth appearance to the fish and if the colours are clear and bright without blurring then the fish has an almost painted gloss like appearance.
These koi have few characteristics for determining a high quality specimen from a low quality one, but the most important aspect of coloration to consider is the blue dorsal line. The blue should be even, continuous and symmetrical.
The veiled koi: Ai Goromo
These striking fish feature purple markings on a white background, and are highly prized by koi enthusiasts. The name of this koi’s classification category, Koromo, means, “veiled” and refers to its vignette. The most prized specimens feature a deep purple robing that covers a portion of the scales while leaving a characteristic fade to red around each marking. The purple colour is a result of blue or black coloration blending into the red.
When young, these fish can resemble Kohaku koi. Often, the purple coloration does not set in fully until the fish has reached maturity. It can be helpful to assess the koi’s value from a Kohaku standpoint, substituting red for deep violet.
The five-color koi: Goshiki
While it is very rare for one of these koi to prominently feature all five colors, the Goshiki koi remains one of the industry’s favorites due to its bright, rainbow-like combination of colors.
A high quality specimen will exhibit red, black, white from the sanke with the grey, and blue colorations from the asagi. This is because the original goshiki were developed by crossing a sanke with an asagi. Only the rarest specimens will feature these colors in equal proportions.
The rarest specimen of Goshiki koi is one with a bright red Tancho mark on the forehead. Also highly sought after are Goshiki koi featuring the stepped patterns often seen in Kohaku koi.
The crow koi: Karasugoi
Karasu is Japanese for, “crow” and refers to the jet black coloration of these koi. They always feature rows of scales running along the dorsal or lateral lines and generally feature a white underbelly. Sometimes, these fish feature a white head and black body.
The best specimens are a deep black with no metallic scales. Note that when any scales are lost the replacement scale that grows will not be jet black and may ruin an otherwise good specimen.
Particularly valuable speciments often feature a wavy white and black pattern covering the flanks of the fish. It is this particular coloration that gave rise to the term, “dragon fish” in reference to koi.
The black net koi: Matsuba
The matsuba is a highly prized and very beautiful fish with a solid, metallic base of color featuring a black net pattern along the scales. The base color change: white, yellow, and red are common varieties, but the black net pattern remains a constant.
The value of this type of koi is based on the metallic sheen of the scales, and the consistency of the black patterning. Vivid contrast between the two colors is highly sought after by koi enthusiasts.
The strange koi: Kawarigoi
Kawarigoi is a catch-all term for just about any variety of koi that does not fit neatly into the existing classification system. Kawari is a word that refers to something strange or with unusual characteristics. It should go without saying that Kawarigoi are a varied bunch, and often contain unusual hybrids between other species.
Finding a quality Kawarigoi is usually up to personal preference. These koi are prized not for their adherence to a standard classification of beauty, but for their individual uniqueness. If you find a Kawarigoi that suits your fancy, it is a good one!
Learning more about koi
While this article touched on some of the most popular and distinctive species, the koi trade is a deep and historically significant one. Further reading is highly recommended for anyone interested in keeping koi as a hobby.