Tancho Koi

Looks how to spot one

scales

Tancho Koi have a sleek, scaly body typical of ornamental carp. Their most striking feature is a single, round red marking on the top of the head, which should be the only red on the fish. The rest of the body is usually pure white, though Tancho patterns can also appear on Sanke or Showa varieties which have additional black markings.3

Grooming and care the hands-on bits

Grooming needs are moderate. Koi produce a heavy waste load, so strong filtration and regular water changes are essential. Overfeeding must be avoided as it quickly degrades water quality. Colour-enhancing foods containing spirulina or krill can be fed seasonally to support the red crest, but constant feeding may yellow the white body.34

Home where they are happiest

Tancho Koi require a large outdoor pond of at least 1000 gallons (3785 litres) with stable water chemistry, strong filtration and good aeration. The pond should have shaded areas and enough depth for the fish to turn and school. They are not suitable for indoor tanks due to their size and waste production.2

Food basics what goes in the bowl

Tancho Koi are omnivores. They do best on a high-quality commercial koi diet formulated for their size, season and water temperature. A varied diet with at least 30% protein supports growth, and colour enhancers such as spirulina or krill can be added seasonally to deepen the red crest. Feed only what they can eat in a short period and remove leftovers to protect water quality.3

The story where it all began

Tancho Koi are not a separate species but a prized colour variety of the common koi (Cyprinus rubrofuscus). The first Tancho is thought to have appeared as a chance mutation among Kohaku koi fry in Japan. A breeder noticed a fry with a single perfect red spot on its head and no other red markings, resembling the Japanese flag. He named it 'Tancho' after the red-crowned crane (Grus japonensis), which has a similar red crown. Breeding true Tancho is extremely difficult because the pattern is not genetically stable; breeders must rely on luck to produce the desired marking. Tancho patterns are formally recognised only in the Gosanke varieties: Kohaku, Sanke and Showa. The variety became highly prized in Japan and later worldwide for its striking resemblance to the Japanese flag and the crane.13

Recognised by the official bits

Gosanke classification

Tancho is a recognised sub-variety of Kohaku, Sanke and Showa koi, defined by a single red marking on the head with no other red on the body.1