Ryukin goldfish
Carassius auratus
intermediate careOverview
The ryukin goldfish (Carassius auratus) is a striking fancy defined by its tall, humped back and deep, short body, topped with flowing twin tails. It reaches 15–20 cm and lives 10–15 years. Ryukins are among the hardier and stronger-swimming fancy goldfish — more robust than ranchu or bubble-eyes — which makes them a good choice for keepers wanting a dramatic fancy that is still relatively forgiving in a spacious cold-water tank.
Tank & water
Give one ryukin 75 litres (20 gallons), plus about 40 litres per extra fish. Priorities:
- No heater needed: ryukins are cold-water fish happy at 18–23 °C, the warm end of the goldfish range.
- Strong filtration: their deep bodies pack in a lot of fish and waste, so over-filter with a capable external filter.
- Room to swim: a large aquarium gives this bulky fancy space to move.
Feeding
Ryukins are omnivores. Feed a quality sinking goldfish food as the staple, with blanched peas and soft vegetables plus occasional frozen treats. Their deep body makes them somewhat prone to buoyancy issues, so avoid dry floating pellets, feed modest amounts once or twice a day, and remove leftovers. Keep up with maintenance and water testing to hold water quality steady.
Tankmates
Keep ryukins with other fancy goldfish of similar build — orandas, fantails, and other twin-tails. Because they swim reasonably well, they can bully very slow varieties like bubble-eyes and celestials, so pair them with fancies of matching ability and avoid fast single-tails. They are not tropical community fish. Plan a group with how many fish in an aquarium.
The ryukin’s dramatic hump develops as the fish matures and is most pronounced in well-fed, well-kept specimens, so it is a good visual barometer of your husbandry. You will see both short-finned and long-finned (or “tassel-tail”) ryukins; the care is identical, though the long-finned form swims a little more slowly and appreciates especially gentle flow. Either way, this is a bold, greedy, personable fish that quickly learns to beg at the front glass.
Ryukin goldfish — frequently asked questions
How big do ryukin goldfish get?
Ryukins reach around 15–20 cm and are deep, heavy-bodied fish thanks to their tall humped back. They are substantial, high-waste fish that need a large, well-filtered tank — see how big do goldfish get.
Do ryukin goldfish need a heater?
No. Ryukins are cold-water fish that do well at 18–23 °C, the warmer end of the goldfish range for a fancy. In most heated homes they need no aquarium heater — see do goldfish need a heater.
Are ryukins good swimmers?
They are among the stronger-swimming fancies — more robust than ranchu or bubble-eyes — but their deep body still makes them slower than single-tails and prone to swim-bladder issues, so feed a sinking food.
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