Koi Glossary

Understanding Koi Terms

New to koi? You’ll often see Japanese words used to describe a fish’s variety, age, colour and breeder. This guide explains some of the terms you’ll find in our listings.

Reading a koi listing

A title such as “Sakai Sanke Tosai – 34cm” tells you:

• Sakai: the breeder name used in the listing.
• Sanke: the koi’s variety.
• Tosai: its Japanese age classification.
• 34cm: its measured length.

Age and size are different. Two koi in the same age class can vary considerably in size.

Age terms

Tosai — koi in their first year.

Nisai — koi in their second year.

Sansai — koi in their third year.

Yonsai — koi in their fourth year.

These are Japanese age classes, rather than exact ages measured from a fish’s birthday.

Common koi varieties

Kohaku — white koi with red markings.

Taisho Sanke, usually shortened to Sanke — white koi with red and black markings.

Showa Sanshoku, usually shortened to Showa — koi combining black, red and white. Showa and Sanke can look similar to beginners, but they are distinct varieties.

Gosanke — the collective name for Kohaku, Sanke and Showa.

Shiro Utsuri — black-and-white koi.

Hi Utsuri — black-and-red koi.

Ki Utsuri — black-and-yellow koi.

Asagi — koi with a blue-grey, net-like pattern across the back, often with red colouring along the sides.

Shusui — a largely scaleless relative of Asagi, usually with a line of larger scales along the back.

Ogon — single-coloured metallic koi, such as golden Yamabuki Ogon or white Platinum Ogon.

Chagoi — usually brown or tea-coloured koi.

Ochiba Shigure — koi with grey and brown markings; the name refers to fallen leaves.

Colour and pattern terms

Beni — red pigment or red markings.

Hi — another term used for red markings.

Sumi — black pigment or black markings.

Shiroji — the white ground colour.

Tancho — a koi with a single red marking on its head and no other red markings on its body. The term can be combined with a variety name, such as Tancho Kohaku or Tancho Sanke.

Maruten — a separate red marking on the head, with additional red markings elsewhere on the body.

Other terms you may see

Doitsu — koi with few or no scales. Some have rows of larger scales along the back or sides.

Ginrin — scales that catch the light with a sparkling appearance.

Hikari — a term referring to metallic lustre.

Tategoi — a koi its keeper or breeder considers to have potential for further development. It is an assessment, rather than a guarantee of future quality.

Breeder — the farm or person that bred the koi. Breeder names help identify its origin.

Quarantine — a period of separation before koi join other fish. At Koi Direct, all koi undergo a minimum of six weeks in quarantine, including two controlled heat-ramping cycles.

Choosing your koi

You don’t need to know every Japanese term to enjoy keeping koi. Start with a fish you like, consider its size and your pond’s suitability, and ask questions whenever something is unclear.

If you’d like help understanding one of our listings, contact us at livingjewelkoi@mailfence.com or call 07479 608821.