That Fish Blog – Aquarium Advice and Information

In past blogs (here and here), we’ve gone over the basics of the Latin scientific naming system. Now, with spring and pond season just around the corner, it’s time to discuss a different naming system – Japanese Koi Nomenclature. Koi are considered some of the most valuable ornamental fish in some parts of the world and mature show quality koi can sell for hundreds or even thousands of dollars much like purebreed dogs and horses. Though other countries raise and produce koi, a Japanese emperor was believed to be the first to begin the practice of keeping koi in ornamental ponds and led to the breeding traditions practiced today. Koi are still usually referred to by their Japanese names for color and pattern.

Like the Latin naming system, the color of the fish plays a large part in the naming system and can point to more specific details in a larger group. For example, Bekko koi are fish that have black markings on a white, red or yellow background. Ki Bekko koi refer to those with a yellow background (“Ki” = “yellow”). The term “hikari” in koi names is also used to refer to a metallic sheen to the scales. Some color terms commonly used for koi are:

Red (Background)	“Aka”
Red (markings)	“Hi”
Orange/Red (background)	“Beni”
Orange	“Orenji”
Yellow	“Ki”
Pale Yellow	“Yamabuki”
Green	“Midori”
Blue	“Ai”
Brown	“Cha”
Gold	“Kin”
Silver	“Gin”
Grey	“Nezu” or “Zezumi”
Black (background)	“Karasu”
Black (markings)	“Sumi”
White	“Shiro”

The most common Japanese terms that are used in reference to koi are those that refer to the pattern on the fish. The most common varieties are Kohaku, Sanke and Showa but there are over 15 commonly-used varieties and each of these can be broken down farther into color variations within that pattern or through lines developed by various breeders.  Some of the most common varieties are:

• Kohaku – Kohaku koi are white with red markings. High quality Kohaku are pure white with no yellow in the coloring and have a deep, solid red color in the markings.
• Sanke – Sanke is one of the most popular varieties. Like the Kohaku, these koi are white with red markings, but Sanke koi also have black markings superimposed on the red and white. High quality Sanke may not be symmetrical in their coloration, but the color should be distributed over the entire body, except for the head.
• Showa – Showa koi are very similar to Sanke but can have much more black on their bodies. The black can be anywhere on the body, including the head, sides and belly (considered undesireable for Sanke koi). Hi Showa is an example of a subvariety of the Showa koi with more deep red color than others.
• Asagi – Asagi koi are one of the most distinctive varieties (and my personal favorite). These koi have blue bodies, white heads and red markings in the tail, fins and face.
• Bekko – These koi have black markings with a white, red or yellow base color. The name of the color is usually used to determine which type of Bekko a fish is (Aka Bekko, Ki Bekko, or Shiro Bekko).
• Goshiki – “Goshiki” literally means “5-colored”, in this case light blue, dark blue, red, black and white. The markings are colored over a white background. This variety can be highly variable in appearance.
• Hikari Utsuri – These koi have the same pattern as Showa and Utsuri koi, but have a metallic sheen to their scales.
• Hikarimoyo – These koi are also metallic but are made up of the metallic koi that are not Showa or Utsuri. Hariwake is a popular variety within this group; this subvariety is metallic silver with orange or yellow markings.
• Hikarimuji – Hikarimuji is another metallic variety but these fish are all one solid metallic color. Pure-colored metallic koi within this category are also known as Ogon koi, leading to the popular Yamabuki Ogons (pale metallic yellow) and Platinum Ogons (pure white and metallic).
• Kawarimono – This variety is like the Hikarimoyo variety in that it included all fish not included in the other popular varieties, but koi within this group can also be divided into their out categories describing their breeder lineage, color or scale traits. The terms “Gin Rin” (meaning sparkling scales) and “Doitsu” (referring to fish that are otherwise scaleless except for mirrored scales around the dorsal fin) are used more in this variety than most others.
• Koromo – Koromo koi are similar to Kohaku, but the scales of the red pattern in Koromo koi have dark edges, leading to an almost crosshatched pattern on these markings.
• Tancho – Tancho koi can sometimes fit within the Kohaku, Sanke or Showa categories, but the markings in Tancho koi are more specific. Tancho koi are white with one red patch on their head, preferably as circular as possible. Tancho Kohaku are the most popular with their pure white bodies and one red patch, but Tancho Sanke and Tancho Showa koi are also popular.
• Utsurimono or Utsuri – These koi are in some ways the opposite of Bekko koi. Instead of having black marings on a colored background, Utsuri koi are black with white, red or yellow markings. Shiro Utsuri, the black and white variety, are the most common, folowed by the more rare Hi Utsuri (red and black) and Ki Utsuri (yellow and black).

This list is far from all-inclusive of all the koi varieties and patterns but can give you a good start in learning the difference between all of the varieties available. As this list demonstrates, koi are some of the most collectible and carefully-bred fish around with a history going back hundreds of years. Koi and pond care can open up a whole new frontier for avid aquarists and the time to start planning your new pond or new pond additions is here! Chart referenced from Wikipedia here.