Fantail Goldfish: Species Profile, Care, Tank Mates, & More!

fantail goldfish
Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: July 11, 2024
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If you are captivated by the lively demeanor and vivid orange hue of regular goldfish but desire a bit more visual allure, you might want to consider getting a fantail goldfish! Read on for an in-depth comparison between it and the standard goldfish, and find out why we recommend it as a possible new aquatic pet.

Article Summary

  • Fantail goldfish have an egg-shaped body and long flowing fins, with double anal fins that split into four lobes, resembling a fan when viewed from the sides.
  • They are peaceful fish and should be kept in groups of at least two of the same species. They should not be housed with aggressive or fin-nipping fish.
  • Proper care and maintenance are essential to prevent common health issues like bloating, constipation, swim bladder disease, and more.

Species Overview

Common namesFantail goldfish, European Ryukin
Scientific nameCarrassius auratus
SpeciesC. auratus
Size6 to 8 inches
Lifespan10 to 15 years
DistributionDomesticated worldwide
Place in tankMiddle
Care levelBeginner

History and Background 

Fancy goldfish- like the fantail goldfish- have a long history of being bred for very specific, often ornamental traits such as wens, unusual colorations, and more. Read on to find out more about the fantail goldfish and what trait it was bred for! 


The fantail goldfish is a fancy goldfish species that was bred for its long flowing fins. Like all goldfish it is originally descended from wild carp and selectively bred for certain characteristics. As such they are descended from the carp family, Cyprinidae. Because of selective breeding you will not see wild fantail goldfish, as they are only a domesticated fish species.

The fantail goldfish species is well known for their calm nature, voracious appetites, and interesting appearance.


Fantail goldfish swimming isolated on black background
Fantail Goldfish Swimming Isolated On Black Background

Fantail’s popular appearance is due to their interesting tail fin that flows out behind them.

What do fantail goldfish look like

Fantail goldfish have an egg shaped body and long flowing fins. Their double anal fin, which they get their name from, splits into four lobes. When looked at from above the anal fins seem to be triangular, but spreads out like a fan when viewed from the sides.


Some aquarists say that when purchasing a new fantail goldfish you should look for one that has two tail fins because those are the better species.

They can have one or two caudal fins which are forked. Each caudal fin is short and round.

How to tell if a fantail goldfish is male or female 

In general males tend to have a smaller body than females, and longer fins and tails. The easiest and most surefire way to determine if a goldfish is male or female is to look at their gonads, or reproductive organs. On a mature male fantail goldfish you will notice small white dots near the vent (right before the underside of the anal fin), female fantail goldfish will have a long white tube leading towards their vent.


The base color of a fantail goldfish is that of orange with either a metallic or nacreous sheen to it. Like most fancy goldfish they come in a wide variety of colors including; yellow, red, white, black, calico, and blue.

There aren’t any named varieties because if a breeder notices a different trait then the fish will be categorized as a different species. For example, if the tail is more than 3/4s of the body then the fish is no longer considered a fantail goldfish but a veiltail goldfish instead.

How big does a fantail goldfish get

On average the fantail goldfish size ranges between 6 to 8 inches in length.

How fast do fantail goldfish grow?

The first 6 months of their life goldfish will grow very fast, roughly 2 to 3 inches. After that they will grow at a steady rate of one inch per year.

Temperament and Tankmates

Many Goldfish Swimming In An Aquarium
Many Goldfish Swimming In An Aquarium

This peaceful fish does well with most tank mates but is easily bullied by others.

Can two fantail goldfish live together?

Yes, fantail goldfish are very friendly and peaceful fish. Because of this it is recommended that you always have at least two of the same species.

How many fantail goldfish should be kept together?

You should keep at least 2 fantail goldfish in the same tank. How many more fantails you keep depends on what tank size you have and whether or not you are willing to maintain it.

How many fantail goldfish in a 10 gallon tank?

The minimum tank size for fantail goldfish is a 30 gallon tank, with an additional 10 gallons for each fantail you add. Unless you are using a 10 gallon tank to keep baby fantail goldfish you should not be using it as your primary tank.

What fish can live with fantail goldfish?

While the fantail goldfish can live with most other peaceful fish because of its peaceful nature, aquarium neighbors should not be aggressive or any fin nippers. Fantails are slow swimmers and can be bullied by faster swimming fish. Peaceful tank mates that are calm, non-aggressive, and are unlikely to bully your goldfish will do well in your goldfish tank.

Bad tank mates include sumatra tiger barbs, red tail catfish, angelfish, and common comet goldfish. More experienced tank owners can experiment with rosy barbs as tank mates, but sometimes these fish don’t make good tank mates so we don’t recommend it for beginners.

Top 5 Compatible tank mates

  1. Bubble-eye goldfish
  2. Zebra danios
  3. Minnows (Rosy Reds and White Cloud Mountain)
  4. Dwarf Gouramis
  5. Ghost Shrimp

If you are looking to keep other goldfish in the same tank, the oranda goldfish, ryukin goldfish, or veiltail goldfish are suitable tank mates.

Tank Requirements

A Fish Tank with Goldfish
A Fish Tank with Goldfish

Because of their large size and bioload, goldfish have surprisingly hefty tank requirements. 30 gallons or more are recommended.

Tank Size

The fantail goldfish is a fairly large freshwater fish that requires a large tank. As slow swimmers it is hard for them to turn around, so you should choose a tank that is square-ish in shape, not elongated and narrow.

Can fantail goldfish survive in an outdoor pond?

Yes, adult goldfish can live in backyard garden ponds as long as the proper water temperature is maintained. Their ancestors, the wild carp, were bred and kept in large outdoor ponds so you should have no issues using one as your fantail goldfish habitat. If kept outdoors you should be willing to maintain an efficient filtration system to ensure good water quality. 

Water Parameters

Tank Size>30 gallons
Water TypeFreshwater
Water Temperature67-73
Water pH6.0-8.0
Water hardness4 to 20 dKH

Tank Setup

What substrate to use for fantail goldfish?

Unlike many other goldfish, this fancy goldfish likes to dig, so you should place sandy substrate in your tank. Fine sand substrate is nice for fish that dig because if they accidentally ingest it, it can pass through their digestive tract without harm. Additionally, rough gravel substrate could lead to physical injury when digging if it has sharp edges.

Do I need a filter?

Yes, for these freshwater fish it is necessary to have filtration, fantail goldfish need a pristine environment. Like others in the goldfish family, this species produces a lot of fish waste and can easily overwhelm your fish tanks’ bioload capabilities.

Should I get a pump for my goldfish?

We suggest using a pump in your goldfish tank as it will allow for more oxygen circulation and stronger water flow, allowing more waste to reach your filter. Additionally if you plan to have planted tanks (which goldfish enjoy!) the addition of a pump replenishes possible oxygen deprivation from the plants.


Plants in aquariums actually breathe some of the oxygen they produce, especially at night when they aren’t able to make more!

Should I use a water heater?

The fantail goldfish can tolerate a wide range of temperatures (65-75 degrees), but if you are keeping other tropical fish in the tank it could be beneficial to have a water heater to keep them comfortable and keep the temperature in the tank consistent.

What temperature do fantail goldfish need

Fantail goldfish thrive in temperatures between 67 and 73, but prefer it to be on the higher side. Unlike comet goldfish and shubunkins they are not cold water fish.

What kind of lighting do fantail goldfish need?

Most freshwater species need some sort of day and night cycle provided by aquarium lights or sunlights and fantail goldfish are no different. Fish need light for 8-12 hours a day, and darkness 12-16 hours a day to establish a circadian rhythm similar to what they would have in nature. If you are using aquarium lighting it is especially important that you turn the lights off, avoid activity close to the tank during the goldfish’s resting hours.

Can I add plants to my fantail goldfish tank?

Fantail goldfish do enjoy heavily planted tanks. The benefits being that they can hide and play in the foliage providing enrichment and stimulation. Live plants that do well in goldfish tanks include Marimo Moss Balls, Java ferns and Anubias. Be aware, as omnivores your fantail goldfish might nibble on the plants if they get hungry.

If you decide to use artificial plants as tank decor we recommend using silk or fine leaf plants so they don’t cut your fish as they swim past.

Diet and Health

Goldfish eating food
Goldfish Eating Food

Like other goldfish, fantail’s are not picky about their diet. But feeding them a high quality diet is important to maintain their health.

What do fantail goldfish eat

Like other goldfish, fantail goldfish are omnivores and can eat a wide variety of food. You should feed your fantail goldfish a varied diet of live foods, vegetables, commercially available flakes and pellets, and frozen foods.

What to feed fantail goldfish?

While each individual goldfish will have their food preferences I like to feed mine a diet consisting of 80% commercially available food and 20% supplemental food such as veggies, freeze dried, live, or frozen food. The reason being is that commercially available goldfish food is specifically made for goldfish to ensure they have all the necessary vitamins and minerals.

However, most commercial food doesn’t have enough crude protein contents which can easily be remedied by supplemental protein sources (like soft brine shrimp, insect larvae, tubifex worms or bloodworms).


Did you know that commercial goldfish flake food is made to enhance your goldfish’s coloring?

How often to feed fantail goldfish 

You should feed your fantail and any other fancy goldfish in your tank one to two times a day

How much to feed fantail goldfish?

You should feed your goldfish according to the three minute rule. This is where you add 3 to 4 floating foods or cut up pieces of food to the tank and start a timer. Once your goldfish has eaten all of the food you can repeat the process until the time is up. Any uneaten food should be immediately removed from the tank.

This method is used so that your goldfish gets just enough food but doesn’t overeat, become constipated, or bloated.

Common diseases of fantail goldfish? 

Due to their proneness to overeating, goldfish often have gastrointestinal related problems. 

Bloating – symptoms include a swollen abdomen appearance and a change from the fish’s regular egg shaped body to a rounder, plump shape. Treatment for bloating includes an epsom salt bath.

Constipation – if your goldfish seems constipated you might also notice a lack of appetite, and lethargy. Generally being constipated means that there isn’t enough fiber in your goldfish’s diet. The most common treatment is feeding your goldfish nothing but shelled peas or blanched spinach and lettuce until they experience normal bowel movements. 

Swim bladder disease – if you notice your fish having trouble swimming, maintaining buoyancy, leaning or fish swimming on its side and back, or not eating they are likely experiencing swim bladder disease. Treatment includes water changes, and salt baths. In severe cases your vet might have to do fish surgery and use a needle to extract excess air.

Additionally, due to the large amount of mess they make, goldfish can develop many diseases due to poor water quality in the goldfish aquarium. Fin rot and other bacterial infections can also come from poor tank maintenance.

Popeye – caused by trauma, or bacterial infection, popeye leads to one or both of a fish’s eye bulging outwards due to fluid buildup and swelling in the eye cavity. If you believe it was caused by trauma make your fish as comfortable as possible with excellent water parameters and a quality diet. To reduce the swelling you can use epsom salt baths. 

Dropsy – often mistaken for bloating symptoms or swim bladder disorder, dropsy symptoms can include swelling of the abdomen, loss of appetite, loss of color, curvature of the spine, and swelling near the anus. The tell tale sign of dropsy is scales pointing outwards resembling a pinecone. Dropsy is most often the result of an underlying condition. Treatment includes correcting underlying problems as well as a broad spectrum antibiotic geared towards gram-negative bacteria to prevent the worsening of symptoms.

How long do fantail goldfish live 

In ideal conditions with proper fantail goldfish care a fantail goldfish can live to be 10 to 15 years on average. This means keeping fantail goldfish is a much larger commitment than keeping other fish.


Goldfish Near Substrate
Goldfish Near Substrate

Breeding these fish can be difficult- you’ll need to keep a close eye on your fish and have multiple tanks readily available- but very rewarding.

Can you breed a fantail goldfish?

While you can breed fantail goldfish, this type of goldfish is one of the harder ones to breed and you will need to do many test spawnings.

How to breed a fantail goldfish? 

If breeding in an outdoor environment you should begin in early spring when the weather starts to warm, if using an indoor breeding tank you can simulate this by warming the water. It is recommended that you use a one to three female to male ratio.

Fantail goldfish suitable for breeding should be healthy, have good coloring, and be fairly young (success rate diminishes after 8 or so years). Within your separate breeding tank you should provide spawning mops such as hornwort or other DIY options for the eggs to be dropped in.


Many people mistake the white breeding tubercles on males to be white spot disease. The difference is that tubercles appear in a regular pattern, where white spot disease is abnormally distributed.

Females and males should be left in the tank for a day or so to spawn and then be removed. Eggs will hatch in three to four days after which you’ll notice the young fish swim to the surface to gulp air to fill their swim bladder. Once they are free swimming you should begin feeding a diet of powdered fry food such as infusoria.

After about 3 days they should be large enough to begin feeding on baby brine shrimp. After 6-10 days you should remove them from the spawning tank to a larger tank to provide them ample room. Because of the large amount of fry you will have to perform lots of water changes as part of your baby fantail goldfish care. 


Because females can lay up to 1000 eggs at one time some aquarists choose to create a brine shrimp hatchery to help with feeding demands.

At this point many breeders begin to separate their fry by various physical aspects such as divided tails, long vs short caudal fin, and coloring. If you’re lucky you might even have a fry with the calico fantail goldfish gene.

For more goldfish breeding tips, watch this video below.

How to Breed Goldfish (Natural Way)

Is the fantail goldfish for you?

After reading our fantail goldfish care guide you might be wondering how you can acquire this amazing fish? Luckily for you most local pet stores carry this variety of fancy goldfish, though you might have to head to a specialty breeder to find some rarer colors such as calico. Either way you’re sure to fall in love with the fantail goldfish as much as we have.


Keeping a fantail goldfish, while moderately challenging, can be very rewarding in the long run as they provide countless hours of entertainment and will be the centerpiece of your tank.

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