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Everything You Need to Know About Fantail Goldfish

Fantail goldfish look very much like comet goldfish. In fact, at a brief glance, you could be forgiven for thinking they were one and the same thing.

But the deep body, broad caudal fins, and wobbling swimming style make the fantail a very distinct variety.

Fantail goldfish

Are fantail goldfish suitable for beginners? What about setting up a breeding tank for these fish? We will be discussing every aspect of fantail goldfish care here in great detail.

What is a Fantail Goldfish

Fantails are the most basic variety of fancy goldfish types out there. Most of the other fancy goldfish varieties build on the fantail goldfish body plan. You will sometimes see white fantail goldfish, black fantail goldfish, and other color morphs in pet stores. However, they aren’t very rare.

Black moors are just fantails with telescope eye genetics. Orandas, ryukins, and other breeds that share the chunky fantail body are also descendants of theirs. However many other fancy goldfish have very different body plans, including lionheads and shubunkins.

Fantails have an egg-shaped body that’s very different from a comet or shubunkin. At first glance they look similar to a ryukin except a ryukin has an even more exaggerated body shape.

Fantails also have a double anal fin and double tail fin. Again, many other fancy goldfish share this feature since they are descendants of fantails. The double tail fin is very eyecatching and trails like a curtain in the currents within your primary tank.

Carassius auratus
  • Common Names: Fantail Goldfish, Calico Fantail Goldfish, Fancy Fantail Goldfish
  • Scientific Name: Carassius auratus
  • Origin: China
  • Length: 6 to 12 inches.
  • Aquarium Size: 20+ Gallons
  • Temperament: Peaceful fish
  • Ease of Care: Very Easy

How to Care for Fantail Goldfish

With their double tail and anal fins, fantail goldfish are a classic variety thanks to their intriguing appearance. Fortunately, they are also some of the easiest fish in the world to care for.

How Big do Fantail Goldfish Get?

Choosing the right tank size for fantail goldfish can be tricky because all goldfish vary quite a lot in size and shape. You can expect your fantail goldfish size to be between 6 and 12 inches long as a full-grown adult.

Choosing the Right Tank Size for Goldfish

This means that your minimum tank size should be 20 gallons, with 40+ gallons better for a bigger goldfish. Not only are fantails thick-bodied; they also poop quite a bit and have a pretty heavy ammonia load.

One way of keeping the tank conditions clean for as long as possible is to provide extra water volume. A small tank setup will foul much faster and require a tank clean on a more frequent basis. The bigger the fantail goldfish tank size the better.

Choosing the Right Tank Size for Goldfish

Also, when choosing your rocks, driftwood, and other decorations, make sure that you provide plenty of fish swimming space. You need to because goldfish are very active fish and can even be clumsy as they grow larger. A fantail looking to find a tasty snack in the gravel will gladly knock over plants and other decorations if they are in the way.

How Long do Fantail Goldfish Live?

The average fantail goldfish lifespan is one of the longest you will ever see compared to other fish in pet stores. All members of the goldfish family are very long-lived. According to Guinness Records, the oldest known goldfish was Tish, a carnival comet that lived to be almost 43 years of age.

This means that any goldfish you buy as a young fish is better thought of as a long-term commitment.

Koi, the larger cousins to goldfish, are even longer lived; several decades is the norm. And the oldest koi of all was dated at over 200 years in age.

So if your new fish ends up dying it is not because goldfish are sensitive freshwater fish.

Choosing a Substrate for Your Fish

Like other goldfish fantails just love to dig. This rooting around the bottom of ponds, lakes, and streams helps them uncover bits of leftover food that may have been missed by other fish.

So I recommend choosing a substrate that will recover well from being displaced.

Sand substrates work well since it is harder to build piles from, unlike gravel. But gravel is more popular among aquarium keepers due to its appearance.

Also, keep in mind that fantail goldfish species will often uproot any live plants that you add to planted tanks while they are digging for food.

It is better to stick to plastic or silk plants since live plants will soon die from being constantly disturbed by your fish. Fine leaf plants like Cabomba may even be eaten by your goldfish after they get uprooted.

Any gravel you choose should be free of sharp edges, which can cause damage to the soft lips and fins of a goldfish rooting along the bottom. Remember, goldfish will take in big mouthfuls of gravel, looking for leftover food. So we don’t want sharp gravel that can cause cuts to form in their mouths, which can become easily infected by opportunistic bacteria and fungi in the aquarium water.

Fantail Goldfish Water Conditions

Fantail goldfish are some of the hardiest aquarium fish around, despite that silly-looking egg-shaped body. Like all fancy goldfish, they are not very picky when it comes to water conditions and quality. While they prefer unheated water fantails will even live alongside tropical fish in a community tank.

That said, you should keep them cool since their growth and metabolisms are optimized for these conditions.

Goldfish are some of the toughest freshwater fish around when it comes to resisting ammonia, nitrite, and nitrate pollution. They can survive conditions that would kill more sensitive fish with next to no ill effects.

Fantail Goldfish Water Conditions

This hardiness comes from the place natural populations of closely related carps are found: stagnant ponds and other bodies of water where other fish have a hard time surviving.

Many members of the carp family, including goldfish, used to be raised as food fish in East Asia for this reason.

But just because fantail goldfish are so hardy does not mean we want to keep them in poor water full of fish waste. Keep up with regular tank maintenance and you will be rewarded with more active and vibrantly colored goldfish.

Goldfish that are stressed by poor water conditions may sometimes start to turn black.

If you have a fantail or other goldfish variety that is not known for naturally turning black, this shift is often a sign that your ammonia levels are too high and becoming toxic.

Fantail Goldfish Ideal Water Temperature

All fancy goldfish species are great additions to a cold water setup where a heater is not needed. However, they tend to be better off in fish tanks rather than backyard garden ponds. Not that they have problems during the summer months. But the winter is a different matter.

Most fancy goldfish species have been bred within indoor fish tanks for so long that they don’t easily go into winter hibernation. Goldfish closer to wild carp will slip into torpor when the water temperature starts to approach freezing.

Torpor is not true hibernation since the fish can enter and leave it much faster. But it is less risky to the life of the fish compared to hibernation.

Keep fantail goldfish indoors where the water temperature won’t go below room temperature (55-70°F).

Skin Lesions, Growths, and Other Issues

Sometimes you might see a growth on fantail goldfish fins, skins, or heads. Goldfish of all kinds are prone to getting skin tags and other benign growths that come from constant contact with the gravel. Sometimes these growths can also come from rubbing up against the aquarium glass, which is a sign that your goldfish tank is too small and in need of an upgrade.

Some skin growths are also viral in nature but it is hard to differentiate them without a veterinary biopsy. If you see other fish in the tank suffering from the same lesions, however, it could be a viral infection rather than an abrasion or genetic factor at play.

In any case, growths and skin tags should be left alone unless you know a veterinarian who specializes in fish surgery (they do exist).

These vets can put a fish under using anesthetics and then snip away the growth without leaving an open wound ripe for infection.

Skin Lesions, Growths, and Other Issues

Other Goldfish Disease Issues

Goldfish are also prone to parasitic infections like anchor worms, especially if you keep yours in an outdoor pond. Fortunately, anchor worms are one of the easier diseases to treat if caught in time. You may also see ich on their flanks, which looks like a faint dusting of white salt crystals.

The long fins of fancy goldfish can be easily injured by fin nipping tank mates or bumping up against sharp edges.

When this happens a fin can become infected by fungi or bacteria, which results in fin rot taking hold.

If you see signs of fin rot you should take immediate action because the disease can be fatal if left to fester for too long. Fin rot works its way down the fin rays until it rots away the cells at the base of the fins.

Once these cells are damaged the fin is unable to regenerate and the disease can then progress into the body of the fish.

Fantail Goldfish Tank Mates

Now that you have your lovely fantail goldfish how about getting some companions to keep in the same tank? What kind of fish are the best companions for them?

Honestly, the best tank mates for fantails are other kinds of goldfish. Since the fish all have the same temperature requirements, eat the same kind of food, and are of the same temperament, it makes things easy. Plus goldfish come in a wild assortment of forms and colors, from metallic blue to pale white, that even a goldfish-only tank is never boring.

That said, there are a few fish species worth a look at as goldfish tank mates.

Fantail Goldfish Tank Mates

Cold Water Tank Mates

White Cloud Minnows (Tanichthys albonubes) are a great addition to any goldfish tank. They are cyprinids and thus close cousins to goldfish and carp.

White Cloud Minnows are found in Vietnam and China and are also known as the Poor Man’s Neon Tetra. Since they require unheated water they form a nice, colorful school that contrasts well with the slower, chunkier fantail goldfish.

More fish that do well in a tank consistent with cold temperatures include Zebra Danios, Dojo Loaches, and Rosy Barbs. Be careful with other species of barbs because many are fin nippers. Tiger Barbs are the worst offenders but they prefer tropical conditions. But there are cold water barb species that would love to nip the double fins of a slow fantail goldfish and are not good tank mates as a result.

Keep away from plecostomus, large loaches, and most other bottom-dwelling fish. Plecos in particular have a bad habit: they love attaching themselves to the sides of slow-moving, broad-bodied fish like goldfish. They will then slurp up some of the mucus on their sides, which is rich in vitamins and nutrients.

Losing mucus is very stressful for fish and opens them up to viral, parasitic, and bacterial infections.

What do Fantail Goldfish Eat?

Another reason why goldfish are so popular is that they are so easy to feed. Goldfish are omnivorous, meaning they need to eat both plant and animal matter. In nature goldfish will eat worms, snails, small shrimp, fish eggs, soft aquatic plants, algae, and anything else they come across that is organic and edible.

So any prepared part of a healthy diet should have both plant and animal ingredients. Look for high-quality additives like spirulina, brine shrimp, krill, and omega-3 vitamins. Garlic oil also helps fight bacterial infections and acts as a flavor enhancer.

Like all freshwater species of fish, goldfish also love live foods and frozen foods. Try offering tubifex worms, bloodworms, brine shrimp, and other treats on a regular basis.

Lastly, when feeding we want to make sure that there is little to no leftover food because it will contribute to water pollution in the form of ammonia as it decays. Uneaten food is usually not an issue when keeping goldfish because they will root around in the gravel for food continually. Unless you are overfeeding, in which case they will get full and uneaten food can remain undiscovered.

So how much food is just enough food for your fish? A good rule of thumb is that a fish’s eye is as big as its stomach. This is not true for every fish but it does work for fantail goldfish. So don’t add any more than would fill the volume of its eye per feeding – that way any leftovers will be swept up between meals.

How Can I Breed Fantail Goldfish?

Goldfish are not very difficult to breed. In fact, so long as you are feeding your fantails with a rich diet and providing them with clean, well-filtered water, you are almost guaranteed to have them breed at some point.

Breeding fantail goldfish

One element to consider when trying to breed fantail goldfish is temperature. In nature (and backyard garden ponds) goldfish wait for the rising temperatures of spring to prepare to spawn. Male fantail goldfish will start growing breeding tubercles on their faces; little white knots on their heads and gill covers.

And you may even see a female fantail goldfish pregnant with eggs. It can be hard to tell since fantails are already very plump fish for their size. But if you see one being chased by a number of fish with breeding facial tubercles you’re looking at a ripe female being pursued by males.

Goldfish are not good parents. Like all cyprinids, they are egg scatterers. This means that when they spawn they simply aim for plants and other weedy material and allow the eggs and fry to fend for themselves.

Collecting Goldfish Eggs

A separate breeding tank is very important because goldfish eggs are very small and have a pale yellow to white color that makes them difficult to see. And as egg scatterers, it is nearly impossible to collect and raise the eggs in a new tank. Instead, you should allow the adult fantail goldfish to spawn and then move the adults.

Many aquarists try adding spawning mops to their setup. If there is nothing else a spawning mop can work well since goldfish prefer laying eggs on plants. But many eggs will still miss the mop and be lost.

If your goldfish aquarium or pond is very large, providing a lot of live or fake plants will help ensure plenty of eggs and young survive to adulthood. Goldfish will eat their babies but the cover provided by plants and other decorations allows the young fry to stay safe until they are too large to be eaten by their parents.

Raising Goldfish Fry

Assuming your fantail goldfish have spawned it will be up to you to care for the eggs and fry. The eggs require a constant temperature, so avoid any swings during the developmental period. Within 3 to 5 days the eggs will ripen, turning a deep yellow, and then the baby fish fry will hatch.

Goldfish fry are helpless for their first few days because they are weighed down by their giant yolk sack. The yolk sack contains all of the nutrients they need to get through these first few critical days.

Once they start lifting from the bottom of the fry rearing tank (3 to 5 days more) the young goldfish are in the free-swimming stage. You can then start offering them powdered fry food, which is small enough to be eaten. However the young goldfish might not recognize prepared food at first – so I recommend having a ready culture of live infusoria to feed them with. Infusoria is a catch-all word for parameciums, amoeba, and other microorganisms that live in mature bodies of water. Since these organisms all move the baby goldfish fry will snap them up with glee.

Within one to two weeks they will be large enough to eat baby brine shrimp nauplii, which are easy to raise yourself. You can start transitioning them onto hand powdered flakes at this point, mixing them in with the live brine shrimp so they get used to eating prepared foods.

Fantail Goldfish: Conclusion

If you want a goldfish variety that is beautiful, inexpensive, easy to care for and a snap to breed, you won’t do much better than fantail goldfish. They retain the classic orange tones that make goldfish some of the most popular fish in the world and will entertain you for decades to come if well cared for.


More Frequently Asked Questions about Fantail Goldfish

Looking for more tidbits of information on fantail goldfish care? Don’t worry, we’ve got you covered with the following frequently asked questions about these beautiful fish.

How Big Does a Fantail Goldfish Get?

Fantail goldfish are average in terms of their final adult size. ou can expect a fantail to grow between 6 and 12 inches long as an adult. But 6 to 8 inches is the average for these fancy goldfish.

Do Fantail Goldfish need Company?

Goldfish are not as social as tetra fish and other schooling community fish so no one knows if they get lonely when kept alone. However, they do interact with one another and seem to enjoy each other’s company. I recommend keeping goldfish either with a few of their own kind or with any one of these 12 goldfish tank mates. Just be sure to choose suitable tank mates that also enjoy living in a cold water setup.

What is the Difference Between a Fantail and a Goldfish?

Fantails are goldfish but not all members of the goldfish family are fantails. A fantail goldfish has double fins; specifically the anal fins and tail fin. They also have a round body shaped like an egg. They are much chunkier than comets and other goldfish closer to the wild carp body plan – but not as extreme as ryukins and other fancy goldfish types.

Can Fantail Goldfish Live with Common Goldfish?

A fantail goldfish will live alongside common goldfish with no problems at all. In fact, the two varieties may even interbreed with one another since they are still the same species. Just like two dogs that look very different can still have puppies. Just keep in mind that common goldfish are often faster to get food since they have a sleek body plan and a very efficient swimming method. Fantails tend to waddle in the water a little when swimming, almost as if they have swim bladder disease. Since they swim slowly, this can make competing for food a little harder for them.

Jason Roberts
About Jason Roberts
Jason is an aquarium fanatic that has been a fish hobbyist for almost three decades.