Overview
Fancy goldfish are the ornamental cousins of the common goldfish: egg-shaped, double-tailed varieties such as the fantail, ryukin, oranda, black moor and ranchu, bred over centuries for rounded bodies and flowing fins. They are slower and daintier than single-tailed goldfish, which makes them favourites for a calm cool-water tank.
That same rounded shape makes them a little more delicate. Their compressed bodies are prone to swim-bladder and digestion problems, so clean water, a good diet and gentle tankmates matter even more than for common goldfish.
| Care level | Beginner-intermediate |
| Adult size | 5-8 in (13-20 cm) |
| Lifespan | 10-15 years |
| Temperament | Peaceful and slow |
| Min. tank | 20 gal (76 L) for one, +10 gal each extra |
| Temperature | 65-74 F (18-23 C) |
| pH | 7.0-8.4 |
| Hardness | 5-19 dGH |
| Diet | Omnivore |
| Schooling | Sociable, keep with other fancies |
Water & tank conditions
Like all goldfish they are cool-water fish that need no heater and thrive around 65-74 F. Fancies are messy and sensitive to poor water, so a well-filtered tank of at least 20 gallons for the first fish, plus regular water changes, is essential. Keep flow gentle, as their long fins tire in strong current.
Aquascape & setup
Give them open swimming space, smooth rounded gravel and no sharp decor that could tear their delicate fins or bump their protruding eyes (as in black moors and telescopes). Hardy plants like anubias and java fern, plus smooth stones and rounded wood, make a safe, handsome setup.
Diet & feeding
Omnivores that do best on sinking pellets or gel food rather than floating flakes, which make them gulp air and worsen swim-bladder issues. Add blanched peas and vegetables to aid digestion. Feed small portions and soak dry food first for the roundest-bodied varieties.
Tankmates & temperament
Peaceful, slow and a little short-sighted, so keep them only with other fancy goldfish. Fast single-tailed goldfish outcompete them for food, and tropical fish need warmer water. A group of fancies of similar size and swimming ability lives together happily.
Breeding
Fancies spawn much like common goldfish, scattering eggs over plants as the water warms in spring. The parents ignore or eat the eggs, so breeders raise the fry separately. Fancy strains do not always breed true, and the fry vary in body shape and colour.
Fun facts
- Every fancy goldfish variety, from the bubble-eye to the ranchu, was bred from the same species as the plain gold carp.
- Their rounded, egg-shaped bodies make them more prone to swim-bladder problems than slim single-tailed goldfish.
- Ranchu and lionhead goldfish have no dorsal fin at all, a trait fixed by selective breeding.
- Black moors have telescope eyes and see poorly, so they find food more by smell and touch.
- Fancy goldfish are slow swimmers and should never be housed with fast common or comet goldfish.
Frequently asked questions
Are fancy goldfish harder to keep than common goldfish?
A little. Their rounded bodies make them slower and more prone to swim-bladder and digestion problems, so they need clean water, sinking food and gentle tankmates, but they are still a good beginner fish.
Can fancy goldfish live with common goldfish?
It is not ideal. Fast single-tailed goldfish out-swim and outfeed the slower fancies, leaving them hungry. Keep fancy goldfish with other fancies of similar size and speed.
Why does my fancy goldfish float or sink?
Rounded fancy goldfish are prone to swim-bladder trouble, often from gulping air with floating food or from constipation. Feeding soaked sinking food and blanched peas usually helps.
Do fancy goldfish need a heater?
No. They are cool-water fish comfortable at room temperature, around 65-74 F, and do not need a heater in most homes.
How big do fancy goldfish get?
Most fancy goldfish reach about 5-8 inches, with a rounder, shorter body than single-tailed goldfish but still needing a roomy, filtered tank.
