6 koi varieties from Single-Variety.
Tancho
A kohaku with all its red concentrated into a single round spot on the head, like the Japanese flag. Tancho are not bred on purpose. They happen when a kohaku's pattern resolves into one perfect circle on the crown. The rounder and more centered the spot, the more valuable the fish. Extremely popular in Japan for obvious patriotic reasons.
$50-$50,000+
Tancho
A sanke where all the red has settled into a single head spot, with black sumi accents remaining on the body. Rarer than tancho kohaku since you need the red to consolidate AND the sumi to stay in good positions. When it works, the clean white body with head spot and scattered sumi is striking.
$75-$40,000+
Kinginrin
Kinginrin is not a variety but a scale type. Gold (kin) or silver (gin) sparkling scales that can appear on any variety. A kinginrin kohaku is a kohaku with glittering scales. In shows, kinginrin have their own class. The sparkle should be even and cover the body well. Diamond ginrin is the most prized scale type.
$25-$30,000+
Bekko
Bekko are simple two-color koi with a solid base and small black (sumi) spots. Shiro bekko (white with black) is the most common. Think of it as a sanke without the red. The sumi should be small, well-placed stepping stones, not large blotches. Clean, minimal, and elegant.
$15-$5,000+
Butterfly
Butterfly koi (also called longfin or dragon koi) have elongated, flowing fins that trail behind them as they swim. They can be any variety crossed with the longfin gene. Purists in Japan do not consider them true nishikigoi and they are excluded from most Japanese shows, but they are extremely popular in Western ponds for their graceful movement.
$15-$5,000+
Doitsu
Doitsu is a scale type, not a variety. Doitsu koi are mostly scaleless with at most a row of large mirror scales along the dorsal and lateral lines. The word comes from Deutsch (German) because the trait came from German mirror carp. Any variety can be doitsu. The smooth skin shows colors differently, often more intensely.
$15-$20,000+