Factfile: Koi

Size: Wild carp reach 39-40in (1m). Most Koi are somewhat smaller. Koi measuring above28in (72cm) are officially regarded as Jumbo Koi.

Distribution: Cyprinus carpio originated in the Dunube and other rivers of the Black Sea basin, but it is now found throughout Europe and elsewhere. Barring some escapes or introductions, Koi are not found in the wild.

Habitat: Carp prefer sluggish or still waters, especially warm ponds with abundant vegetation. Koi tolerate a wide variety of conditions, from muddy natural ponds to clinically clean Koi pools.

Temperature: From well below 10C (50F) to above 30C (86F) - but not for extended periods at the higher temperature.

Diet: A wide range of foods, which must regularly inlcude vegetables. Koi especially like regular treats such as prawns, brown bread, lettuce and garden peas. However they cannot digest the outer skin of peas, so crush them and spit the skin out.

Breeding: An egg-scattering species which will eat its own eggs. Spawning usually begins at a water temperature of around 20C (68F). Spawning activity is very vigorous and can result in injuries to the fish. The use of spawning brushes (ropes) or mats, or construction of a large floating net (cage) in which selected brood fish can be isolated, is strongly recommended. Eggs hatch in 3-4days at temperatures between 20-22C (68-72F).

Major Koi Categories
Non-Metallic Varieties

Kohaku: White base colour with red markings

Tancho Sanke: (or Sanke) White base colour with superimposed red and black markings

Showa Sanshoku: (usually refered to as Showa) Black base colour with red and white markings.

Bekko: Black markings on a white, red, or yellow base colour

Utsurimono: White, red or yellow markings on a black base.

Asagi: Blue base with red on the belly, fins and sides of head; top of head is light greyish blue.

Shusui: Similar to the Asagi, but with dark blue colorations restricted to the large Doistu scales; naked areas are light blue, except for the head, which is light greyish blue.

Koromo: White base colour with red markings that are over-laid with darker patterning.

Kawarimono: All other types of non-metallic Koi, including single coloured fish, e.g. Kigoi (yellow fish), almost single-coloured fish, e.g. Hajiro (black fish with white fin edges) and Goshiki (five coloured fish)

Tancho: Single red marking on the top of the head; this classification is reserved for Kohaku,  Sanke and Showa Koi that bear this very distinctive head spot.

Metallic Varieties

Hikarimono: (or Ogon) Single coloured fish.

Hikari-Utsurimono: Metallic versions of Utsuri and Showa.

Hikarimoyo-mono: Term embracing all other types of metallic Koi

Other Categories
Kinginrin: Fish having 20 or more reflective/sparkling scales; previously, judging of this category at Koi shows embraced fish of any variety, provided they had the appropriate scalation.

Goshiki: Five coloured Koi classified within the Kawarimono in countries other than Japan.

Doitsu: Doistu-scaled fish are generally classified under their colour variety.