The king of goldfish, seen from above.
Ranchu are bred to be viewed looking down into a shallow tub: the arched back, the hooded head, the tail tucked flat. Everything on this site follows that view, from the anatomy chart to the way we size a tank.
Sarasa (red-and-white) and solid red ranchu, top view · illustration
The king of goldfish
The ranchu (蘭鋳, ranchū) is a Japanese breed of fancy goldfish. It has no dorsal fin, a short, deep, egg-shaped body, a back that arches smoothly down to a tucked tail, and a raspberry-like head growth called the wen. In Japan it is called the king of goldfish.
Ranchu were developed from the Chinese lionhead and refined in Japan from the late 1800s. Japanese ranchu are judged from above, in shallow tubs. Thai and Chinese breeders later developed a side-view ranchu with a bigger head and tail, which is the type most shops sell today.
An adult ranchu is 5 to 8 inches of body and lives 10 to 15 years with good care. It needs about 20 gallons of wide, shallow water, sinking food and gentle flow. It comes in red, red-and-white, black, calico, white, blue and chocolate.
Prices run from under $20 in a pet store to thousands for Japanese show lines. The price guide explains why, and the buying guide shows what to look for before you pay.