Shubunkin goldfish
Carassius auratus
intermediate careOverview
The shubunkin goldfish (Carassius auratus) is the prized calico single-tail, famous for its speckled “nacreous” scales in blue, black, red, orange and white. Underneath that beautiful patterning it is a tough, fast, cold-water fish that grows to 25–30 cm+ and lives 15–20+ years — every bit as demanding of space as a common or comet goldfish. The blue tones are especially valued and show best in a pond viewed from above.
Tank & water
A single shubunkin needs 150 litres (40 gallons) minimum and is truly a pond fish. Essentials:
- No heater: shubunkins are cold-water fish — hold a steady 18–22 °C and let them tolerate cooler outdoor temperatures.
- Strong filtration: they are heavy-waste fish, so over-filter with a capable external filter.
- Room and stability: a large aquarium or pond keeps water quality steady and lets them swim.
Feeding
Shubunkins are omnivores. Feed a quality sinking goldfish food, supplemented with vegetables like blanched peas and greens plus occasional live or frozen treats. Give small portions once or twice a day and remove leftovers — overfeeding quickly fouls the water of these messy fish. Keep up with maintenance and water testing.
Tankmates
Keep shubunkins with other fast single-tailed goldfish — comets and common goldfish make ideal companions. Their pace and enthusiastic feeding will stress and out-compete slow fancy goldfish, so keep the two groups apart. They are not suited to tropical community fish, which live too warm and are too easily bullied at feeding time. A mixed group of single-tails in a pond is the ideal — plan numbers with how many fish in an aquarium.
There are two main forms you may see: the standard London shubunkin, which has a short, rounded tail, and the Bristol shubunkin, prized for its large, heart-shaped tail. Both need identical care — a big, cool, well-filtered home — and both develop their finest blue colouring only when kept in good conditions for several years, so patience and space pay off directly in how beautiful your fish become.
Shubunkin goldfish — frequently asked questions
How big do shubunkin goldfish get?
Shubunkins are single-tailed goldfish that reach 25–30 cm or more, the same as commons and comets. They are pond-sized fish — see how big do goldfish get — so plan for their full adult size from the start.
Do shubunkin goldfish need a heater?
No. Shubunkins are cold-water fish that prefer 18–22 °C and overwinter well in ponds. A heater is unnecessary and warm water shortens their lifespan; stable cool water with strong filtration is what they need.
What is special about a shubunkin?
Its calico colouring — a nacreous mix of blue, black, orange, red and white speckling over a pearly body. In every other respect a shubunkin is a hardy, fast single-tailed goldfish that needs the same pond-scale care as a comet.
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