The Ryukin is the most popular goldfish breed. Its attractiveness comes from the very short, round, egg shaped, almost-circular body with medium to long finnage. The tail should always be held very high and well spread. Red, red/white and calico are the most common color combinations. White and red/black also available but most breeders prefer red/white. With a few exceptions, most adults reach lengths of around 4 to 5 inches.
The Ryukin should be fed with food high in carbohydrates and roughage to help the development of their round, full bodies. The Ryukin is a good goldfish breed for those who are thinking of spawning and raising their own goldfish, as they produce many good quality fry in each spawn. Watch for the crimson red/white Ryukin with a pronounced humpback as this is a most desirable features in this breed. Although the short tail version demands more attention in the far east, in US, longer tail are also very popular.