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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
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

One ryukin needs about 95 L, plus roughly 40 L for each additional goldfish, with heavy filtration to handle the waste. Aim for 16 to 23 C and a pH of 6.5 to 8.0. Keep it with other fancy goldfish of similar swimming speed. Feed sinking pellets, blanched peas and spinach, and frozen bloodworms or brine shrimp, splitting food into small daily portions.

In the wild

The ryukin is a fancy goldfish with a short, deep body and a tall, pointed shoulder hump behind the head. It has long flowing fins and a paired tail, and is one of the sturdier fancy strains. The rounded body means it swims slowly and is prone to swim bladder issues, so it needs smooth decor and no strong current. Keep it cool, roughly 16 to 23 C.

Good to know

The ryukin was developed in Japan from Chinese fantail stock and takes its name from the Ryukyu Islands, the trade route it arrived by. Its trademark high back is a fixed genetic trait selected over generations. Like all Carassius auratus strains it is a cool water fish, not a tropical one.

Did you know

Ryukins are among the greediest fancy goldfish and will eat until bloated, so measured feeding is the main way to keep their round bodies healthy.

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.

How big does a Ryukin get?

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

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