Fantail

Identification

The fantail is the simplest fancy goldfish, and the one all the others are built on. The body is egg-shaped, deeper and shorter than a common goldfish but without the humped back of a ryukin, and the dorsal fin is normal and upright. The tail is the defining feature: two caudal fins side by side, divided right up to the top and held stiffly spread like an open fan at rest; a tail joined along the top edge is a show fault. The anal fins are paired as well. Fin length is moderate; the long, drooping tail of a veiltail and the draped finnage of an oranda are departures from the fantail standard.

To rule out its relatives, check the head and eyes: a fantail has a smooth head with no wen, unlike the oranda, and normal eyes, unlike the telescope and black moor. Against the ryukin, look for the shoulder hump behind the head; a fantail’s back rises gently. Colours run from orange and red through red-and-white, calico, white and black, and the body deepens noticeably between the first and third year.

Ryukin, fantail or tamasaba?

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  Ryukin

  A hump behind the head

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  Fantail

  A smooth egg shape

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  Tamasaba

  A ryukin’s back, one tail

Three deep-bodied goldfish side by side: a ryukin with the hump behind its head ringed, a fantail with its smooth back ringed, and a tamasaba with its single long tail ringed.

1. Ryukin. The back climbs sharply behind the head before the dorsal fin, on a deeper body. In a young fish the hump is slight, so judge body depth too: the British standard asks for about 80% of body length in a ryukin and 65% in a fantail.
2. Fantail. The body rises in one smooth egg shape with no hump, over a double tail.
3. Tamasaba. A back that rises behind the head like a ryukin’s, with a full dorsal fin, but a single undivided tail, which in the photograph is a long one.

Photographs: Ryukin, Lerdsuwa, CC BY-SA 3.0; Fantail, ProjectManhattan, CC BY-SA 3.0; Tamasaba, Desaix83, after Ghasem1122, CC BY-SA 3.0. Rings added.

The varieties

Fewer distinct forms than most fancies, because the fantail is the baseline that the others were bred away from.

• Short-finned fantail. The standard, and the more robust of the two.
• Ribbontail or long-finned fantail. Longer, draping fins. Handsome, slower, and far easier to damage on decor.
• Calico fantail. Calico over nacreous scales. Frequently mistaken for a shubunkin, which is a single-tailed fish with the same colouring and completely different needs.
• Black and chocolate lines. Black fantails commonly lighten with age, for the reasons the black moor page sets out.

And “fantail” is also used loosely as a shop label for any egg-bodied, double-tailed goldfish without a wen or telescope eyes. That is usually accurate enough, but it is worth checking the back for a ryukin’s hump before assuming.

How it develops

Less dramatic than a wen or a telescope eye, but the tail is worth watching. Breeders pick for a divided tail at about four weeks and for body and tail at eight to twelve, so the lobes separate long before six months, and most goldfish hatch bronze and lose the dark pigment during the first year.

A tail fault tends to stay. A juvenile whose lobes are fused along the top, or carried permanently to one side, may keep that fault, and it can affect how the fish swims as well as how it looks.

The body keeps deepening after the tail has settled, and the two do not finish together. A fantail that stays slim may simply come from a slimmer line, which is worth knowing because it changes what the fish needs: a slimmer, faster fantail is closer to a comet in appetite and swimming than to an oranda, and it will outcompete round-bodied tankmates at feeding time.

Otherwise this is the least surprising fancy to raise, and that is the real argument for recommending it to beginners. There is no wen that might not arrive, no eye rotation, no pattern that takes three years to settle. Much of what you can see at a year is what you will have at three, apart from the deepening of the body, which for a first fancy is worth more than any amount of drama.

Why this is the fancy to start with

Worth stating plainly, because the fantail is usually recommended without a reason attached.

It has no added fragility. Normal eyes, no wen, a dorsal fin, and fins that are long by single-tail standards but not by fancy ones. Every other fancy adds at least one thing that needs managing.

It keeps its balance better than the extreme forms. The body is compressed, so buoyancy trouble is possible, but the shortest-bodied fancies, such as the pearlscale, are thought to be more prone to it.

It tolerates a wider temperature band than most fancies, which forgives a room that swings — goldfish water temperature covers where that band sits.

It can hold its own among other fancies, so a mixed fancy tank does not starve it, which chasing and bullying explains is the quiet failure mode of mismatched tanks.

But “easy” is relative to other fancies, not to a comet. A fantail still needs the volume, the filtration and the weekly water change that goldfish for beginners sets out. It is the gentlest introduction to fancy goldfish, not a fish that looks after itself.

Choosing one

A test worth learning, and few people do it.

1. Look at the fish from behind as well as the side. The two tail lobes should be even and carried apart. A fused or single-sided tail may make a fish swim crookedly, and tail faults are common in cheap stock.
2. Then from above: a straight spine and an even body. Bent spine covers what a curve means when you see one.
3. Then swimming. Level, unhurried, fins open, not struggling to stay off the bottom or the surface.
4. Read the shop, as choosing and bringing home a goldfish sets out, and then quarantine for at least four weeks.

Where you will find one. A widely available fancy, in most aquatic shops, and one of the few where you do not need a specialist to get a good one. The quality range at a single price is enormous, though: body depth and the way the twin tail is carried are what separate a good fantail from an indifferent one, and both are visible in a juvenile. Spend the time choosing rather than the money — in this breed the selection is worth more than the budget.

Personality and behaviour

Fantails are steady, sociable fish that spend the day working over the substrate. They are among the quicker swimmers of the fancies, able to hold their own with orandas, ryukins and telescopes and often first to a pellet. That same speed makes them a poor match for the slowest breeds, such as ranchus and bubble eyes, which can be quietly outcompeted, and they are in turn outpaced by comets and commons. In a small group of similar fish they are peaceful to the point of being uneventful, which is a compliment.

Aquarium requirements

Recommendations for a first fantail range from 60 to 100 litres (16 to 26 US gallons); the higher figures assume the fish reaches its full adult size, and 75 litres (20 US gallons) is a sensible minimum. Add 40 to 50 litres for each further fancy goldfish. A long, low tank gives more swimming room and gas exchange than a tall one of the same volume; the tank size calculator turns your own group into figures.

Filter for five to ten turnovers an hour, but soften the outflow with a spray bar or a sponge so the fish are not pushed around. A common range is 18 to 24 °C (64 to 75 °F). Fantails tolerate cooler water than most fancies and are sometimes overwintered in mild-climate ponds, but stable, moderate water indoors is the safer routine, and the water temperature guide explains the trade-offs. Change 25 to 50 percent of the water weekly according to nitrate, use sand or a bare bottom, and keep decor smooth so the double tail cannot snag.

Feeding

Base the diet on a quality sinking pellet made for fancy goldfish, soaked for a minute if your fish bolt food, and feed two or three small meals a day, each gone within a minute or two. Add shelled peas, blanched zucchini or spinach once or twice a week for fibre, and gel food or frozen daphnia for variety. Floating food is often blamed for a fantail’s buoyancy troubles; the sinking versus floating guide explains why. Skipping one day a week does no harm.

Common health considerations

Fantails are among the healthier fancy goldfish, but they share the round-bodied tendency to buoyancy problems: floating after meals, tilting, or struggling to stay level. Diet is a common cause, and a switch to sinking food with a few days of peas sometimes resolves it; the floating guide covers the other possibilities, and persistent trouble deserves a water test, since poor quality produces the same signs.

Newly bought fish often carry ich, which shows as white grains on fins and body within a week or two of arrival, so quarantine and watch. The double tail catches on rough decor and tears in strong current, and heals in clean water. Like all goldfish, fantails show ammonia or nitrite stress as clamped fins, red streaks and lethargy; the remedy is water changes, not medication.

What goes wrong, in order

What you see	Usually	Where to look
Floating or tipping after meals	Often diet, though other causes exist	Floating upside down
Split or frayed tail	Sharp decor, or strong flow	Torn fins
Long trailing faeces	Too much dry food, not enough fibre	Constipation
Resting low, fins clamped	Water quality, or temperature	Sitting on the bottom
Swimming crookedly from new	A tail fault, not an illness	Nothing to treat
Thin, among quicker fish	Outcompeted at feeding	Chasing and bullying

Three of those six are the diet, which is unusual — most breeds on this site fail at the tank first. A fantail’s weak point is its gut, and sinking versus floating food plus a vegetable or two a week fixes most of it.

Is a fantail right for you?

It suits you if you want a fancy goldfish and have not kept one before, if you want something that will cope with an ordinary room and an ordinary routine, or if you want a fish that mixes well with other fancies.

It does not suit you if it would share a tank with single-tails, which will beat it to everything, or if you were hoping for something that stays small. A fantail reaches 15 to 20 cm and often lives around ten years or more.

And it has little to answer for, in the terms goldfish welfare sets out. The double tail costs it some swimming efficiency and the compressed body costs it some digestive room, and that is the whole bill — which is a short one next to a bubble eye’s.

History and origin

The doubled tail is one of the oldest goldfish mutations, recorded in China during the Ming dynasty, the earliest dated account being from 1596. By then goldfish were being kept indoors in ceramic bowls and tubs, which let breeders notice and select unusual shapes that would have been lost in a pond. A shorter body followed the doubled tail, and together they produced the fish we now call the fantail.

Its twin tail runs through many later fancy breeds, which differ from it by a hood, a hump, protruding eyes or a missing dorsal fin. It remains the breed most often recommended in the beginner’s guide as a first step into fancy goldfish, because it has stayed close to a shape that works.