Shubunkin Goldfish: Ultimate Guide (Care, Diet, Breeding & More)

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Written By Matt Stevens

Hi, I'm Matt! I've been obsessed with fishkeeping for over 15 years now and created this site to share my knowledge with others.

Shubunkin Goldfish are a popular Goldfish variety that brings unique elements of coloration and flair to modern aquariums.

Their long, sparkly fins, ease of care, and unmatched aesthetic appeal make them an excellent option for spicing up home aquariums.

But even with their hardy nature, some questions around these fish never seem to go away. For instance, what do Shubunkin Goldfish eat? Are they compatible with Neon Tetras? Or, is it even possible to breed them in captivity?

This guide will help you understand what it is like to care for Shubunkin Goldfish at home. It will focus on the fish’s size, general appearance, diet and feeding habits, tank size, behavior, tank mates, breeding, and more!

Species Overview

If you struggle to pronounce their name correctly, you can call them the Speckled Goldfish, Calico Goldfish or Harlequin Goldfish. These fish are part of the Cyprinidae family with the scientific name Carassius auratus.

Lifespan15 years
Care LevelEasy
Behavior & TemperamentPeaceful
CompatibilityOther peaceful fish
Food and DietOmnivores
Size12 inches
Tank SetupPlanted freshwater
Tank Size (Minimum)75 gallons

Typically, Shubunkin Goldfish are a special breed of Fancy Goldfish, with colorful markings and flowing fins that are sure to capture anyone’s attention.

While there are conflicting reports about Shubunkins’ original habitat, every indication confirms Japan as their initial home. However, these fish are no longer available in the wild these days, and most of the existing species are captive-bred in Asia.


Generally speaking, Shubunkin Goldfish have an average lifespan of 10 to 15 years, which can improve or decrease depending on the level of care you give them at home.

As expected, they will have a longer lifespan in backyard ponds with enough swimming space and well-maintained vegetation.


Any comparison between the Shubunkin Goldfish and the Comet Goldfish ends at the body shape. Usually, Shubunkins have distinctive calico markings and elongated fins that distinguish them from most Goldfish varieties.

The modern aquatic world has witnessed up to three varieties of the Shubunkin Goldfish, including the London, Bristol, and American variants.

And all three Shubunkin varieties have thin, B-shaped bodies with short, wide heads. Also, these fish have pale white or iridescent bodies with blue or black markings. In addition, they have beautiful shades of red, yellow, gray, orange, white, or blue.

In conclusion, Shubunkin Goldfish have upright dorsal fins and are easily recognizable by their beautiful, nacreous scales.


Now, let’s talk about the aforementioned Shubunkin Goldfish varieties:

American Shubunkin

American Shubunkin Goldfish have long tails resembling Comet Goldfish. Therefore, they are perceived as the true replica of the original Shubunkin Goldfish from Japan.

Bristol Shubunkin

On the other hand, Bristol Shubunkins are famous for their full, B-shaped tails with an expensive price tag. They are the rarest of Shubunkin varieties, hence their high cost in the global fishkeeping community.

London Shubunkin

Finally, London Shubunkins have characteristic slender bodies and short tails. Also, they are easily recognized by their perfectly rounded fins and are the most popular Shubunkin variety.


Shubunkin Goldfish’s maximum size in captivity will depend on the actual environmental conditions. A typical variant with the right conditions will reach 5 to 6 inches in full maturity.

But you may notice sharp variations depending on how committed you are to caring for them. They can easily surpass the standard length in captivity if you provide suitable water conditions and a spacious environment like an outdoor pond.

Sometimes, Shubunkin Goldfish can reach up to 12, 14, or 18 inches in full maturity with quality care.

Shubunkin Goldfish Care

Shubunkin Goldfish care is an exciting adventure for many reasons. They are hardy fish with straightforward care needs that many aquarists can readily meet regardless of their level.

Normally, these fish will thrive where most other freshwater fish have failed, and that’s why you should be excited about keeping them in a home aquarium.

In the next section, we will be talking about their care guidelines in detail.

Tank Size

Now, this is where it gets somewhat confusing.

As a committed aquarist, you may have read lots of confusing reports about the Shubunkin Goldfish’s ideal tank size in captivity. So, to clear the air, here’s what you should know.

While Shubunkin Goldfish are moderately sized species that can readily adapt to smaller tanks, they thrive in larger tanks.

So, the general belief that these fish thrive in 15 or 20-gallon tanks might be right or wrong depending on the exact number of fish at home. In many cases, such a tank will be enough for just one Shubunkin fish in captivity.

In general, the guiding principle should be that the higher the number of fish, the larger the habitat. And in our opinion, a 75-gallon tank is the most suitable option from the start.

Such tank capacity will give your lovely Goldfish enough room to roam freely in their new habitat and limit the possibility of aggression.

Consider a backyard pond from the get-go if you have multiple fish in the same space or an entire school to manage. It will save you from the endless battles against freshwater diseases such as Ich.

Water Parameters

Shubunkin Goldfish are not like ordinary tropical freshwater fish. They are temperate fish that will thrive in cool waters with the right tank setup.

They can tolerate slight changes in water temperature but require neutral pH and proper aeration to survive in captivity. So, here’s the summary of what makes up the ideal tank for the lovely Shubunkin Goldfish at home:

  • Water temperature: 65°F-72°F
  • Water hardness: 5-19 dGH
  • pH levels: 6.0-8.0

What to Put in Their Tank?

Don’t be fooled by their small body sizes. Shubunkin Goldfish can easily sour the tank water with their enormous waste products. So, the right filtration system is an essential must-have when designing the perfect habitat for your beautiful Shubunkins.

The right filtration equipment should lessen the burden of cycling the tank water regularly and help with regulating the ammonia and nitrate levels as expected. That aside, Shubunkin Goldfish require ideal water flow, which implies pumps and air stones will be other vital additions to the home aquarium.

You don’t want to go overboard with excess decorative elements that will only limit the fish’s swimming space. Instead, you should introduce the right amount of natural plants to complete the hiding spots and moderately sized gravel as the most befitting substrate.

Assuming you already know Shubunkins’ cheeky behavior in front of plants, you will want to introduce natural plants carefully and only with the right anchoring systems. If you can’t tolerate Shubunkins’ notoriety for uprooting water plants, consider other options such as plastic and silk plants.

Never forget that the most significant aspect of a Shubunkin Goldfish’s tank décor is enough swimming space. Consequently, adding driftwoods and smooth rocks to the tank will only make sense if you have the right quantities.

Common Diseases

Shubunkin Goldfish are hardy species that will tolerate different conditions inside the aquarium. However, they are not immune to all conditions affecting the freshwater fish community.

You should watch out for Ich, a parasitic infection that will always trouble most freshwater fish species in captivity. It presents itself with obvious spots all over the fish’s body, and its highly contagious nature will force you to isolate the affected fish as soon as you can. Without early intervention, Ich can kill the entire school quickly.

Furthermore, you will want to monitor your Shubunkin Goldfish keenly for any signs of fungal diseases, fin rot, and skin flukes that can also trouble them at home. Finally, these fish will also be susceptible to common internal conditions like swim bladder disease and dropsy.

Usually, a bigger percentage of the above-mentioned diseases are easily avoidable with high living standards. Poor water quality and compromised tank conditions are the obvious causes of many diseases affecting these fish.

And even though simple medications will help relieve the main symptoms, the safest natural remedy is maintaining clean tank water by regulating all the water parameters. Another vital aspect of optimal care and growth is diet, as you will learn in the next section.

What Do Shubunkin Goldfish Eat?

Shubunkin Goldfish are omnivores that feed on whatever food item they can find inside the tank. However, a constant supply of high-quality food with the right nutritional elements is perfect for their health and well-being.

Some of the best options include flakes and pellets. Also, you can feed them on live and frozen foods such as tubifex worms, daphnia, brine shrimps, and bloodworms to fulfill their nutritional requirements.

Shubunkin Goldfish’s huge appetite in captivity makes them appear greedy at times. And this is where you could make a terrible mistake by overfeeding them.

To be sure you are feeding them just the right amount of food at any given time, you can introduce a suitable meal plan that lasts only 2-3 minutes. Such an underrated technique will lessen the risks of overfeeding your fish in captivity and prevent endless digestive issues in the entire community.

Behavior & Temperament

Like many varieties of the Fancy Goldfish, the Shubunkin Goldfish are peaceful and social fish that will only want to explore their new habitat.

They are excellent scavengers and peaceful bottom dwellers at the same time and will always crave their own space inside the tank.

If they are not exploring the tank searching for food, they will be dashing around, showing their unmatched prowess in swimming. They will have no problem living with other peaceful species in the same aquarium.

Shubunkin Goldfish Tank Mates

For the ideal Shubunkin Goldfish’s tank mates, you will want to avoid the more aggressive fish and slower species that will struggle to compete for food with the agile Goldfish.

Choosing the best tank mates also means considering the environmental conditions. Unfortunately, this also presents the biggest challenge to many aquarists.

Usually, Shubunkin Goldfish are temperate species that thrive in cooler waters in captivity. So, finding similar fish that will enjoy the same conditions will be difficult.

Regardless of how you approach it, here are some of the best fish species you can easily keep together with Shubunkin Goldfish:


Breeding Shubunkin Goldfish is easier if you provide the right tank conditions. Usually, it starts with females who will lay many eggs during the spawning period in the spring season.

You can encourage breeding by introducing a separate tank to keep the adult fish during spawning. For many aquarists, determining the fish’s sex can be challenging. But the breeding tubercles in the male species should help you differentiate the two genders when setting up a new breeding tank.

Typically, the breeding tank should have the correct spawning elements, such as fine leaf plants, smooth rocks, or spawning mops.

During the breeding season, it’s advisable to lower the water temperature to 60°F before increasing it slowly depending on the existing conditions. This is the easiest way to recreate the temperature shift from the winter to spring, that’s perfect for Shubunkin breeding.

You should remove the adult fish as soon as breeding is complete to prevent them from eating the fry. Then, the eggs will hatch after 4-7 days if successful spawning occurs.

After hatching, you can feed the little fish on liquid or powdered food until they are ready to try other food sources like baby brine shrimps. The baby Shubunkin Goldfish will have shades of brown or blue throughout their bodies until they obtain the suitable coloration.

Final Thoughts

Shubunkin Goldfish are an excellent Goldfish variety for beginner-level aquarists and experienced hobbyists. They are perfect for community tanks and backyard ponds and can live peacefully with most other fish species in the same aquarium.

If you choose to keep them at home, you will love their agility inside the aquarium and the unique color elements they will add to your tank.

Shubunkin Goldfish also fit the bill when you need the best alternatives to Koi fish. If you want value for money with a beautiful Goldfish variety, we would gladly recommend the Japanese Shubunkin Goldfish to anyone!