Shubunkin

Carassius auratus

Also known as: Calico goldfish, Harlequin goldfish

Water Parameters

• Temperature: 10–24°C
• pH: 7–8.4
• Hardness (GH): 89–357 ppm (5–20 dGH)

Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.

Care Summary

A single-tailed goldfish prized for its colour rather than its shape: the shubunkin wears 'calico' nacreous scaling, a mottled overlay of blue, black, red, orange, and white with a distinctive matte, pearly finish, blue being the most prized and the hardest to fix. In body and hardiness it is a common or comet by another name, fast, cold-tolerant, reaching 20 to 30cm, and best suited to a temperate outdoor pond or a large aquarium. Two forms are sold: the slimmer London and the larger-finned Bristol, the latter with a bold, rounded, butterfly-like tail. Kept with other single-tailed goldfish in cool, clean, well-filtered water, it is a hardy, long-lived, and beautifully-patterned pond fish, and one that, like all goldfish in Australia, should never be released.

Tankmates

A single-tailed goldfish and a pond staple, so it follows the single-tail rule: house it with commons and comets, not with the slow fancy varieties it would outcompete. Shubunkins are fast, hardy, and reach a good size, unsuitable for small fish and shrimp. The London shubunkin has a short, common-like body and fins, while the Bristol shubunkin carries a large, rounded tail; both are kept the same way. They are excellent temperate pond fish, and in Australia, as with all goldfish, they must never be released into local waterways.

Compatible with

• Common Goldfish
• Comet Goldfish

Avoid keeping with

• Fantail Goldfish
• Oranda
• Ranchu
• Bubble Eye
• Cherry Shrimp
• Betta
• Tropical Warm Water Species

Common Problems

• outgrowing small tanks (reaches 20-30cm)
• being kept with slow fancy goldfish it outcompetes
• loss of blue colouration in poor conditions or through breeding
• heavy bioload demanding strong filtration

Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20