Ryukin Goldfish
Carassius auratus
About this strain
The Ryukin is built like a fancy goldfish turned up to eleven — its most striking feature is a pronounced dorsal hump just behind the head, giving the body a steep, angular profile unlike any other variety. Paired with a deep belly, a full double tail, and flowing fins, it creates a silhouette that's unmistakably Ryukin. Common colors include red, red-and-white, calico, and chocolate. The hump height is a quality indicator in competition fish. Ryukins are among the more robust fancy varieties and can be aggressive at feeding; house with equally sized tank mates.
Origin
Developed in Japan, believed to have arrived via the Ryukyu Islands (Okinawa) from China in the late 18th or early 19th century. It became foundational to many Japanese fancy goldfish breeds.