Ranchu Goldfish
Carassius auratus
About this strain
The Ranchu is often called the "King of Goldfish" in Japan, and one look explains why — it has a deeply curved, arch-shaped back with no dorsal fin, a broad egg-shaped body, and a dramatically downturned tail tucked beneath the body rather than fanning outward. The head may develop modest wen growth with age. Viewed from above (the traditional Japanese judging perspective), a top-quality Ranchu has perfect bilateral symmetry. Red, red-and-white, and calico are typical colors. Sensitive and slow; pristine water quality is non-negotiable. Not for beginners.
Origin
Developed in Japan from Chinese Lionhead imports during the Meiji era (late 19th century). Japanese breeders, particularly in the Tokyo and Osaka regions, refined the breed standard over generations into the arch-backed form known today.