Ryukin Goldfish; Care Guide, Lifespan, and More

Ryukin goldfish are a gorgeous Japanese variety of Fantail ornamental goldfish. 

Both Ryukin and Fantail goldfish are suitable for beginners to the hobby. You can keep Ryukins in aquariums and outdoor fish ponds, provided the fish are given the correct care. However, like all goldfish species with rounded, egg-shaped bodies, these Fancy goldfish tend to be prone to swim bladder problems.

Keep reading to find out everything you need to know about caring for and breeding the beautiful Ryukin goldfish.

Origins Of The Ryukin Goldfish

All goldfish are thought to originate from China. 

Back in the early 1700s, a species of wild Prussian silver carp was raised in ponds as a food fish. A few brightly colored orange fish appeared among the carp, and those early fish keepers kept them as ornamental pond fish. Goldfish were quickly traded with Japan, and by the 1800s and 1900s, goldfish, as they became known, reached Europe and the US.

Most Fancy goldfish varieties you find in today’s hobby were developed in Asia by enthusiasts who experimented with breeding and crossbreeding the fish. Today, the Ryukin goldfish is one of over 125 varieties of captive-bred Fancy goldfish types. 

Although the original Prussian carp is still relatively widespread, you won’t see Ryukin goldfish in the wild environment. None of the modern Fancy goldfish varieties occur in nature. Any goldfish that their owners release don’t survive for long, as the fishes’ bright colors and clumsy swimming style make them vulnerable to predators.

What is a Ryukin Goldfish?

Ryukin goldfish are one of over 200 varieties of goldfish that are seen in the hobby. 

These are egg-shaped Fancy goldfish with a short, stubby body. Ryukins have a characteristically high back that’s often described as a “dorsal hump.” The dorsal hump starts at the fish’s neck, giving the head a somewhat pointed appearance.

The caudal or tail fin is a split or double fin. Ryukins also come in a long-tailed version that’s commonly called the Ribbon-tail or Fringe-tail.

Ryukin Goldfish Lifespan

Goldfish are relatively long-lived fish that can live for up to 30 years.

However, Ryukin goldfish have a life expectancy of between ten and 15 years. In an exceptional case, these Fancy goldfish can live for an impressive 20 years if they are provided with a high-quality, balanced diet and excellent living conditions. 

What Size Are Ryukin Goldfish?

Usually, Ryukin goldfish grow to around 6 inches in length. 

However, there are records of some huge Ryukins reaching a massive 10 inches!

So, you’ll need to bear that in mind when you buy an inch-long tiddler from your local fish store! These goldfish grow rapidly, and you need to make sure that your fish tank is large enough to accommodate them.

Colors And Patterns

The Ryukin goldfish is available in lots of different colors and patterns, including:

  • Red
  • Red and white
  • Tri-color
  • Calico
  • White
  • Chocolate

The Ryukin goldfish typically has metallic or nacreous scales.

Price And Availability

Ryukin goldfish are usually available in good fish stores and online. 

However, these attractive fish are generally more expensive than other, more common Fancy varieties. The red and white coloration is the most commonly seen and is the least expensive. You can expect to pay more if you want a long-tail variety of Ryukin since these specimens are pretty rare. 

Is The Ryukin Goldfish Suitable For Beginners?

Ryukin goldfish are one of the hardier Fancy goldfish varieties. These fish can live in fish tanks and garden ponds, provided that the environment is suitable and their tank mates are not over-competitive.

That said, you do need an efficient biological and mechanical filtration system to cope with the amount of waste that the fish produce.

Ryukin Goldfish Care Guide

In this part of our guide, we explain how to successfully care for the beautiful Ryukin goldfish.

Tank Size

You might have heard that goldfish only grow to fit the size of their container. That’s an urban myth! Goldfish simply keep on growing, regardless of the size of the tank they’re living in. Unfortunately, if the aquarium is too small, that leads to developmental problems, such as stunted growth.

Like most Fancy goldfish varieties, Ryukins grow pretty fast during their first few years, so we recommend that you buy the largest tank you can afford to save you having to upsize in the future. Even if your tank is far too big for the tiny baby fish at first, they will soon grow to fill it!

We recommend at least a 10-gallon tank, ideally larger. If you want to keep more fish, you’ll need to add a further 10 gallons per fish.

Tank Shape

Ryukin Fancy goldfish are poor swimmers, and long-tail varieties will struggle to cope in a deep tank, so a long, shallower aquarium is best for these fish.

Goldfish are oxygen-hungry critters, so you want a tank with plenty of surface area for efficient gaseous exchange. Mature Ryukins are pretty much incapable of jumping. However, juvenile fish are known to jump out of the water when alarmed. So, you need a tank with a cover slide or a well-fitting lid. Also, if the tank is covered, the water won’t evaporate as quickly, and dust and debris can’t get into the water and pollute your tank.

Do not keep Ryukins in a goldfish bowl! 

The old-school, traditional goldfish bowl is not a suitable home for Ryukins. Bowls are too small, and they don’t offer sufficient surface area for efficient gaseous exchange.

How Many Ryukin Goldfish Can You Keep?

Ryukins enjoy the company of other Fancy goldfish. However, they do need plenty of space in which to swim and explore their habitat. So, you must take care not to overcrowd or overstock your aquarium or pond.

If your goldfish don’t have sufficient space, they will get stressed, and injuries are more likely to occur.

As a general rule of thumb, you need to allow 1 inch of fish per 1 gallon of water in your goldfish tank or pond. 

Water Parameters

Ryukin goldfish are able to live in cold water, preferring a temperature of between 65o and 72o Fahrenheit. However, it’s worth noting that these hardy fish can still thrive in an outdoor pond when the temperature falls to a couple of degrees below freezing.

Ideally, the water pH should be between 6.0 and 8.0, with a water hardness from 5 to 19 dGH.

The levels of ammonia and nitrite in the water must be zero, and nitrate levels should ideally be below 20ppm. 


Goldfish are dirty creatures that produce lots of waste every day. Ryukins are no exception, and you need a highly efficient filtration system that circulates the water around your fish tank at least four times every hour to cope with the mess the fish make.

However, although a powerful filter system will keep the water clean and safe for the fish, it will also generate quite a lot of current through the tank, which is a problem for Fancy goldfish. The fish are such poor swimmers; they can’t cope with a powerful flow.

To solve that problem, you should choose a filter unit with an adjustable outflow feature or buffer the current from the outflow with plants or decorations.

Tank Maintenance

Regular tank maintenance is essential for your Ryukin Fancy goldfish to thrive and grow. 

Every week, you need to carry out 30% water changes to get rid of accumulations of nitrates from the water. If nitrates are allowed to build up in the water, your fish will suffer, and your biological filter will be overloaded. 

Ideally, you should use an aquarium vacuum every week to get rid of leftover food, organic waste, and plant debris that would decompose and pollute the water. Waste tends to accumulate underneath internal filter boxes, beneath decorations, and around the base of plants. 

Living plants make a good addition to your tank, but you must keep them tidy by regularly snipping off dead leaves and damaged stems. Algae that are growing on the viewing panes should be scraped away so that you can see your fish. However, goldfish are omnivores that enjoy grazing on green algae, so you might want to leave a small patch or two for your fish to eat.  

Tank Decoration

How you decorate your Ryukin’s tank is a matter of personal choice. We think that these beautiful fish are best displayed against a natural background, but that’s entirely up to you.

Safety Considerations

Fancy goldfish are clumsy at the best of times, so we recommend avoiding rough, sharp objects that could injure your fish, especially if you have long-tailed Ryukins.

Choose smooth stones, pebbles, and driftwood for decoration, but avoid twisted roots and resin ornaments with rough or sharp surfaces.

The best substrate for Fancy goldfish is smooth, large-gauge gravel.

What About Living Plants?

Living plants are an excellent addition to any aquarium. 

Plants use nitrates as natural fertilizers, as well as removing carbon dioxide from the water and giving off oxygen. However, unfortunately, goldfish of all species don’t always mix well with living plants!

Like most Fancies, Ryukins love to rummage around in the substrate, hunting for morsels of food, uprooting your plants in the process. Goldfish also enjoy nibbling on tender plant shoots, and they can wreak havoc on your carefully aquascaped tank in no time! However, some hardy plant species, such as Marimo Moss Balls, Anubias, and Java fern, are tough and unpalatable for the fish, so those plants usually survive.

Not everyone wants the hassle of growing and caring for living plants in a goldfish tank, so you might want to consider using silk plants instead. Although the fish might still dislodge the plants, at least they won’t kill or eat them!

However, don’t use plastic plants. Some cheaper plastic plants are very hard and have nasty sharp points that could easily injure a trailing tail or scratch the fish, potentially enabling bacteria to enter the wound and set up an infection.


Ryukins don’t need light in their tank to survive. That said, you will need light for living plants to thrive, ideally a minimum of eight hours every day for photosynthesis.

Although tank-kept fish live in an artificial environment, they do appreciate a clear night/day cycle. When “daylight” comes, the fish know that it’s time to become active, search for food, and begin spawning. When the light fades to darkness, the fish sleep. When deprived of a day/night cycle, the fish become stressed. Stress can damage the Ryukins’ auto-immune system, leading to serious health problems.

If your aquarium lighting unit has an auto-timer feature, that’s great. However, if not, a cheap timer plug from a DIY store works just as well.

Nutrition and Feeding

Ryukin goldfish are omnivorous creatures, feeding on a blend of plant matter, algae, and meaty protein. In fact, goldfish are notoriously greedy and will have a go at eating pretty much anything that comes within their reach!

Feed your Ryukins a balanced diet that includes Fancy goldfish pellets and flakes, freshly blanched vegetables, and frozen meaty foods. Although it’s cheaper and more convenient to feed the fish commercially prepared dried foods, you must include meaty food in their diet.

Round-bodied goldfish are extremely susceptible to constipation and other digestive disorders that can affect the fish’s swim bladder function. That can make it even more difficult for the fish to swim properly, stressing them out and potentially leading to disease outbreaks in your tank. 

Including meaty foods and fresh veggies in the diet helps to keep things moving through the fish’s digestive tract, thus preventing digestive problems and keeping the fish healthy.

What About Live Foods?

Goldfish living in a garden pond will eat insects, worms, small crustaceans, and insect larvae that they find in their habitat. 

However, although you can buy live foods from pet stores, we urge caution. Often, these foods come with hitchhikers, such as bacteria and parasites that can harm or even kill your goldfish. Similarly, you shouldn’t take live foods from your local river or pond, as the water could contain harmful chemicals or parasites. 

Unless you have access to a home brine shrimp hatchery, we recommend that you satisfy your Ryukins’ meaty protein requirements with frozen foods.

How Much To Feed Ryukin Fancy Goldfish

Ryukin Fancy goldfish should be given two to three small meals every day.

Only offer the fish as much as they will eat in a few minutes to avoid overfeeding.

What Are Good Tank Mates For Ryukin Goldfish?

Goldfish are sociable creatures that tend to thrive when kept in small groups of similar types. You can confidently mix various forms of Fancy goldfish in a pond or tank without problems. For example, you could keep a mixture of Ryukins, Butterfly Tail goldfish, Black Moors, and Veiltail goldfish in the same tank or pond, which would create a beautiful, harmonious display.

However, we recommend that you don’t mix slim-bodied goldfish with Fancies. Fancy goldfish of all types are poor swimmers that will struggle to compete for food with the more agile, faster, slim-bodied fish. Also, the barging and bumping that typically occurs at feeding times can result in injuries to the slower fish, and the stress will almost certainly make your Ryukins sick. 

Invertebrates, such as snails and large shrimp, can make good additions to a goldfish tank community. However, we suggest that you steer clear of very tiny species of fish and inverts that might be viewed as a food source by your greedy Ryukins. Finally, fin nippers should be avoided as they will hassle and attack the slow-swimming Fancies, especially those with trailing tails.

Ryukin Goldfish Health and Diseases

Ryukin goldfish are hardy creatures, provided that you keep their tank clean and give them a high-quality, varied diet. 

That said, all goldfish can suffer from a few common fish diseases, including the following:


Ich is also known as White Spot Disease or Ick.

The condition is caused by Ichthyophthirius multifiliis, a freshwater parasite that attacks weakened or stressed fish, especially new additions to your tank.

At first, the fish will flash or flick their bodies against the substrate and other solid objects in the aquarium as they attempt to dislodge the parasites from their skin. As the Ich lifecycle progresses, the fish develop a scattering of tiny white spots across their body, gills, and fins.

Thankfully, you can usually treat White Spot Disease successfully with an over-the-counter medication that you’ll get from a good pet store or online. 

Bacterial Infections

If your fish are weak or stressed, they can be vulnerable to bacterial infections. The symptoms of infection depend on the type of bacteria that’s affecting the fish. However, general signs of a bacterial infection include:

  • Ulceration
  • Inflamed patches on the skin 
  • Lethargy
  • Torn or ragged fins
  • Missing scales
  • Poor appetite
  • Labored breathing

Most bacterial infections are treatable with broad-spectrum antibacterial medication that you’ll get from good pet stores or online.


Flukes are various species of external parasites that attach to freshwater and marine fish. Common species flukes include:

  • Anchor worms
  • Fish lice
  • Skin flukes

You often find flukes attached to new fish, hidden among the leaves of plants, and with live foods. 

To keep flukes out of your fish tank, avoid using live foods and put anything new into a separate quarantine tank for at least two weeks before adding the livestock to your main tank. It’s also a good idea to treat the quarantine tank with an antiparasitic medication and rinse plants thoroughly in slightly salted water.

Swim Bladder Problems

As previously mentioned, round-bodied goldfish of all types are susceptible to digestive disorders that can cause swim bladder problems.

Generally, these issues are easily solved and prevented by feeding your Ryukins a balanced, varied diet that includes fresh veggies and plenty of meaty protein. You can buy treatments for swim bladder problems from good fish stores and online.

Breeding Ryukin Goldfish

Ryukins are surprisingly easy to breed in both your fish tank and garden pond. In fact, pond-kept goldfish tend to spawn readily, without any help from their owners, and often, you’ll spot swarms of baby fish swimming around in your pond during the late spring and early summer months.

You can breed Ryukin goldfish in a fish tank, too, as long as you give them a varied, high-quality diet. Of course, you’ll need a mixture of male and female fish for a successful Ryukin breeding project, and that’s easier said than done!

The two sexes are virtually impossible to tell apart when goldfish are juveniles. You have to wait until the fish are mature and in breeding condition before you can differentiate between the boys and the girls. Male goldfish tend to be slimmer than females, and they develop white prickly growths or tubercles on their gill covers and head when ready to breed. Female fish are plumper when carrying eggs, although that can be difficult to spot in egg-shaped goldfish, such as Ryukins.

Spawning Tank

You can breed Ryukin goldfish in your main fish tank, but we recommend setting up a dedicated spawning tank. A separate 20-gallon tank is a good option, as that provides the fish with lots of space, keeping stress at bay and helping to encourage successful spawning.

Bring your fish into breeding condition by increasing their food allowance and including plenty of high-protein foods two to three weeks prior to spawning. Professional breeders generally keep their male and female breeding pairs separate during that conditioning period to make spawning more likely when the fish are introduced.

Like their wild carp relatives, goldfish spawn in the spring when the water warms up. So, you can trigger breeding by increasing the tank temperature by three degrees every day until the temperature is between 68o and 74o Fahrenheit. Fill the tank with plenty of lush plants, and include several spawning mops and flat rocks where the fish can lay their eggs.

Keep the spawning tank clean by performing 20% water changes daily until spawning commences.


During spawning, the male Ryukin pursues the female around the aquarium, pushing against her body until she lays her eggs. Spawning can take several hours, during which time the female can lay up to 10,000 eggs. Once the eggs are released, the male Ryukin fertilizes them. At that time, you need to remove the parents from the spawning tank to prevent them from eating the eggs and fry.

After a week or so, the fry emerges and is immediately free-swimming. At this stage, you can feed the baby Ryukins live baby brine shrimp, spirulina, and finely crushed goldfish flakes.

When the fish reach an inch or so, they can join the adults in your main tank. All juvenile goldfish are a drab brown or bronze color and won’t develop their adult colors until they’re around two months old.

Final Thoughts

I hope you enjoyed our guide to the beautiful Ryukin goldfish. If you did, please take a moment to share it!

Ryukin goldfish are a variety of Japanese Fancy goldfish. These beginner-friendly Fancies can make an unusual, attractive addition to any large coldwater setup or garden pond. Feed the Ryukins a varied, balanced diet, keep the aquarium water pristine and the tank well-maintained, and these gorgeous fish can live for up to 15 years.

Do you keep Ryukin goldfish? Did your fish breed successfully in your tank or pond? Tell us about your Ryukins in the comments box below.

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