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Variety of Goldfish

Ryukin

Carassius auratus

One of 12 varieties of Carassius auratus · See all varieties →

Also known as Ryukin goldfish, Fringetail goldfish, Japanese ribbontail

FreshwaterFish

Ryukin (Carassius auratus)
Asturio Cantabrio · CC BY-SA 4.0

Varieties · Carassius auratus

See all 12 →

Care at a glance

Temperature
61–73°F
16–23°C
pH
6.5–8.0
Adult size
7.9 in
20 cm
Minimum tank
25 gal
95 L
Temperament
Peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Middle
Diet
Omnivore
Difficulty
Medium
Breeding
Medium
Rarity
Common
Family
Cyprinidae
Origin
A fancy goldfish strain developed in Japan from Chinese fantail stock, bred from wild Carassius auratus native to slow freshwater in East Asia.

Overview

The ryukin is a fancy goldfish with a short, deep body and a tall, pointed shoulder hump behind the head. It is one of the sturdier fancy strains, but not a beginner's fish.

Did you know

Ryukins are among the greediest fancy goldfish and will eat until bloated.

Caring for the ryukin

One ryukin needs about 25 gal (95 L), plus roughly 40 L for each additional goldfish. Its rounded body makes it a slow swimmer, so give it smooth decor and no strong current.

Like all goldfish, it is a cool water fish, not a tropical one. Keep it at 61 to 73°F (16 to 23°C) and a pH of 6.5 to 8.0, with heavy filtration to handle the waste.

Feed sinking pellets, blanched peas and spinach, and frozen bloodworms or brine shrimp. Split the food into small daily portions. Its round body is prone to swim bladder issues, and measured feeding is the main way to keep it healthy.

Ryukins are peaceful and social, and they want the company of their own kind. Keep a ryukin with other fancy goldfish of similar swimming speed. Breeding them is of medium difficulty.

Good to know

The ryukin takes its name from the Ryukyu Islands, the trade route it arrived by. Its high back is a fixed genetic trait, selected over generations, and it has long, flowing fins and a paired tail. Like all goldfish strains, it belongs to the family Cyprinidae.

In the wild

The ryukin was developed in Japan from Chinese fantail stock. Its wild ancestor, Carassius auratus, is native to slow freshwater in East Asia.

From published sources

Tank mates

Each fish here is named as a tank mate for the ryukin by at least two published care guides. Every partner here handles cool water. The tank needs about 20 gallons (75 liters) for the first fancy goldfish and 10 gallons (38 liters) for each extra one.

Sources: Practical Fishkeeping, Aquarium Co-Op, Fishkeeping World, Aquarium Source, Tropical Fish Hobbyist.

Check the full mix in the stocking calculator

Common questions

Is a ryukin a different species from the goldfish?

No. A ryukin is a variety of the goldfish, Carassius auratus. It is kept the same way apart from difficulty, adult size, tank size and temperature.

What size tank does a ryukin need?

A ryukin needs at least 25 gal (95 L). It spends most of its time in the middle.

What does a ryukin eat?

A ryukin eats sinking pellets, blanched peas and spinach, and frozen bloodworms or brine shrimp. Split its food into small daily portions.

How big does a ryukin get?

An adult ryukin reaches about 7.9 in (20 cm).

What fish can live with the ryukin?

Published care guides name weather loach, bristlenose pleco, bulldog pleco and variable platy, among others. Every partner here handles cool water. The tank needs about 20 gallons (75 liters) for the first fancy goldfish and 10 gallons (38 liters) for each extra one.

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