Best Ryukin Goldfish Tank Mates

Ryukin goldfish are an unusual, beautiful variety of Fancy goldfish that many aquarists would love to add to a community tank with other fish species.

But can Ryukins live with other fish? How many Ryukin goldfish can live together? And are Ryukins aggressive fish?

Read this comprehensive guide to learn what fish make the best Ryukin goldfish tank mates.

What size tank do Ryukin goldfish need?

Ryukin goldfish are a type of Fancy goldfish that usually grow to reach between 6 and 7 inches long. However, it’s not unknown for Ryukins to grow to as much as 10 inches in length!

That means you’ll need a pretty sizable tank to accommodate a few Ryukins and some suitable tank mates. 

When shopping for goldfish, it’s essential to bear in mind that those tiny little fishes you see in pet stores are usually only a few months old. You’ll be astounded at just how quickly juvenile goldfish grow! 

I was amazed to see that my inch-long Fancies literally doubled in size in just two weeks! So, you must remember that a baby Ryukin will quickly get too big for a small fish tank.

So, we recommend that you buy a 20 to a 30-US gallon (15 – 25 UK gallon) aquarium to start with so that you won’t need to upgrade your tank only a matter of months after bringing home your new pets.

In addition, you should know that for each extra fish you decide to get, you’ll need to allow a further 10 US gallons (9 UK) to your tank size.

Keeping it clean!

Although on the face of it, a small fish tank might seem to be okay for a Ryukin, all goldfish are filthy creatures that make one heck of a mess in their tank. 

Goldfish are effectively swimming garbage disposal machines, constantly scavenging for morsels of food. Unlike many other fish species, goldfish don’t have a stomach. So, whatever the fish eats simply passes from its mouth through the digestive system and out into the water as waste.

In a small tank, the water quality will quickly suffer, potentially poisoning your fish. 

So, a large tank with an appropriate size filtration system is essential for these dirty fish. 

That means healthier water for your fish and less time and work maintaining the tank for you.

red and white goldfish swimming around clear but reflective fish tank

What tank shape is best for Ryukin goldfish?

Ryukins are clumsy, slow swimmers that can develop beautiful flowing finnage once mature. Those gorgeous fins look fabulous, but their weight is also something of a handicap to the fish, making it difficult for them to reach the surface to feed. 

For that reason, a rectangular tank is better than a tall, deep one.

In addition, a rectangular tank offers plenty of surface area for good gaseous exchange. Excellent gaseous exchange is critical for a goldfish tank since these are very oxygen-hungry fish.

Fancy goldfish can easily become stressed if they can’t comfortably negotiate their environment and if dissolved oxygen levels in the water are low. Stress leads to a compromised immune system and outbreaks of disease. So, never keep goldfish in a tank that’s too small.

What about a tank lid?

Although baby goldfish can be surprisingly quick and agile, they don’t generally jump, and adult Ryukins certainly do not leap out of the water!

However, we still recommend that you choose a tank with a lid or at least a cover slide. A lid prevents dust and debris from settling on the water and polluting the tank and can also help to prevent water evaporation.

Goldfish Bowls

Goldfish bowls are not suitable for goldfish of any variety!

Although many of us kept a single goldfish in a bowl when we were children, traditional goldfish bowls are absolutely not suitable for goldfish.

Why not?

So, goldfish bowls are simply too small and don’t provide enough space for a fully-grown goldfish to swim around. 

In addition, the surface area in a fishbowl does not facilitate good gaseous exchange, which is essential for the health and well-being of goldfish.

Can Ryukin goldfish live in a garden pond?

Yes, theoretically, Ryukins can live in your garden pond. 

That said, there are a few downsides to keeping Fancy goldfish in an outdoor pond:

  • Fancy goldfish prefer a slightly warmer water temperature than slim-bodied fish, such as Comets and Shubunkins. If you live in a cold climate with very harsh winters, Ryukin goldfish might need to be kept indoors during the winter months.
  • Ryukin goldfish are cumbersome, slow swimmers that will almost certainly struggle to feed if they are forced to compete with faster species, such as Comet, Shubunkins, and Koi. That will cause stress and even starvation in extreme cases.
  • Ryukins can easily be injured during feeding frenzies or when barged and bumped by faster swimmers.

That said, the winters in my region (US) are relatively mild, and I have successfully kept Ryukins and other Fancy goldfish in a garden pond.

Are Ryukin goldfish aggressive towards other fish?

Ryukin goldfish are not aggressive. Like all Fancy and slim-bodied goldfish, Ryukins love to spend time in the company of other goldfish and similar fish species.

You might occasionally see your Ryukins chasing each other. That’s usually juvenile or stress-related behaviour that typically happens in a new aquarium. 

Once the fish have had a few days to acclimate to their new world and to each other, the frantic pursuit usually stops.

You might notice male goldfish appearing aggressive when spawning. The males often chase the female around the aquarium, trying to shimmy against her in an attempt to stimulate the female to deposit eggs. That behaviour is stressful for the female and sometimes results in minor scrapes and injuries. 

Can Ryukin goldfish live with tropical fish?

Ryukin goldfish are peaceful creatures that generally get along with quite a few other species, including some tropical fish.

Now, you know that all goldfish are coldwater fish. So, how come Ryukins can live with some tropical fish? Well, that’s because all Fancy goldfish varieties prefer slightly warmer water than their slim-bodied cousins.Provided that your tank is kept in a warm room where the temperature doesn’t fall below around 70° Fahrenheit, you can keep the following tropical fish species with Ryukin goldfish:

Photo of Rosy Barbs


Platies are brightly colored livebearers that live in small schools and are extremely popular community fish. The fish grow to around 3 inches in length, so they’re too big to be eaten by your goldfish.

Although Platies breed very readily in captivity, your Ryukins will probably eat most of the eggs and fry. That said, a few will probably survive, so you’ll have a self-sustaining population.

River Murray Rainbowfish

River Murray Rainbowfish are absolutely beautiful fish that thrive in cooler water temperatures of around 70° Fahrenheit. Interestingly, these fish display their most vibrant colours in cool water.

Rosy Barbs

Rosy barbs are peaceful fish that won’t trouble your Ryukins, spending much of their time schooling in the central area of the water column.

Rosies can reach up to 6 inches long, so you need a spacious aquarium of at least 30 gallons to house them as part of a community with goldfish.

Checkered Barbs

Checkered/Chequered barbs are not commonly seen in the aquarium, which is a shame, as they are attractive, peaceful fish that are perfect for a community setup. These barbs grow up to 2 inches in length and must be kept in schools of at least eight fish.

White Cloud Mountain Minnows

White Cloud Mountain minnows are small schooling fish of around 2 inches long. Although their size makes them small enough to make a meal for a large Ryukin, minnows are fast, agile swimmers that can easily keep out of range of the slower goldfish.

However, we recommend that you use plenty of thick plants, rocks, and driftwood where the White Cloud Mountain minnows can hide when necessary.

Zebra Danios

Zebra danios are extremely popular community fish that are a staple of many home aquariums. 

These danios can live in cool water temperatures of 65° to 77° Fahrenheit and should be kept in large groups for the best effect and to ensure that the fish feel secure and thrive.

Dojo Loach

Dojo loaches are also known as Weather loaches.

Loaches inhabit the bottom of the aquarium, keeping out of sight most of the time among your decorations and plants. In fact, Dojo loaches are nocturnal, so you won’t see much of them unless you have moon-lighting in your tank.

Weather loaches get their name from their ability to detect changes in barometric pressure. The loaches go crazy when the pressure changes, darting around the tank in a frenzy as they sense the coming storm front.

If you decide to keep Dojo loaches in your goldfish tank, you’ll need a tightly fitting lid. Dojos are accomplished climbers, and they will escape if there are any holes they can wriggle through. You’ll also need a large tank of at least 55 gallons for Dojo loaches.

Corydoras Catfish

There are over 100 varieties of Corydoras catfish to choose from, most of which can make good tank mates for Ryukin goldfish.

Corys are bottom dwellers, spending their days scavenging on the substrate and around plant bases or resting motionless, watching their tank mates from below.

Corydoras catfish grow to reach up to 3 inches long and must be kept in small groups of five or more.

Hillstream Loach

The Hillstream loach prefers cooler water conditions of between 68° and 75°F. 

Unlike most species of loach, these shy fish are diurnal, spending their days hiding around the substrate under pieces of wood, beneath rockwork, and underneath bushy plants.

Best tank mates for Ryukin goldfish

If you would prefer to stick to keeping goldfish rather than tropical species, there are lots of varieties to choose from!

Since Ryukins can be stressed and injured by faster swimming, slim-bodied goldfish types, we recommend choosing other varieties of Fancy goldfish for tank mates.

Any of these Fancy goldfish make excellent tank mates for Ryukins:

  • Butterfly Tail
  • Butterfly Telescope 
  • Oranda
  • Celestial Eye
  • Dragon Eye
  • Fantail
  • Lionchu
  • Lionhead
  • Pearlscale
  • Ranchu
  • Tamasaba
  • Veiltail

Freshwater snails and large species of shrimp can also be a good choice. 

These invertebrates make a handy cleanup crew, munching through algae and organic waste, relieving the load on your filtration system, and helping to keep the environment clean.

However, make sure that any shrimp species you choose are too large for the Ryukins to eat!

Unsuitable tank mates for Ryukin goldfish

As previously mentioned, you should avoid keeping Ryukins with the likes of Shubunkins, Comets, and other large, fast-swimming fish.

Very small invertebrates, bite-sized fish, and species that are well-known as fin nippers should also be avoided as these are unsuitable tank mates for Ryukin goldfish.

How many fish should Ryukin goldfish live with?

Like all goldfish, Ryukins are happiest when kept in large groups. In theory, you can keep as many goldfish as you want to, as long as your pond or aquarium is big enough to accommodate them without overcrowding.

Fish kept in overcrowded tanks usually suffer from poor health, and disease outbreaks are common. 

Those problems are caused by stress. When fish are stressed, their immune system is compromised, leaving the fish open to attack by parasites and bacterial infections and causing a general loss of condition. 

In an overcrowded tank, feeding time is highly stressful since the largest fish tend to push out the smaller ones, leaving them to go hungry. In extreme cases, the weakest fish can even starve. 

One effective way to prevent feeding frenzies is to feed your fish at separate ends of your aquarium or pond. 

The fish naturally form two shoals, preventing bullying and physicality. Everyone gets their fair share of the spoils, and no fish are damaged by the barging and bumping that can happen.

Final Thoughts

I hope you enjoyed our guide to the best Ryukin goldfish tank mates. If you found the article helpful, please share it!

Ryukins are sociable, peaceful fish that do best when living in a community setup containing peaceful fish of a similar size. Other Fancy goldfish make the best tank mates for Ryukins, although some tropical species can also work well.

Avoid keeping very small fish and shrimp that the goldfish could eat. In addition, slim-bodied goldfish should be avoided, as these fast swimmers can bump and barge the slower Ryukins and outcompete them at feeding times.

1 thought on “Best Ryukin Goldfish Tank Mates”

  1. I recently got 2 calico ryukins. They were purchased a week apart, but from the same breeder and same age. They seem to be fighting now they are back together. Is this normal?


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