The Shubunkin Goldfish: The is not a beginner fish. It is a cold-water species that produces enormous waste, needs real filtration, and outgrows most tanks within a year. I have kept goldfish in ponds and large tanks for over 25 years. Here is the honest care guide most people need before buying one.
A goldfish in a bowl is not thriving. It is slowly suffocating.
Goldfish live 10 to 15 years, sometimes longer. This is a decade-long commitment to large water volumes, heavy filtration, and consistent maintenance.
A goldfish kept properly is more impressive than most tropical fish. The problem is almost nobody keeps them properly.
Table of Contents
- What Most Care Guides Get Wrong About Shubunkin Goldfish
- A Brief Overview Of The Shubunkin
- Classification
- Origins and Habitat
- What Does They Look Like?
- Shubunkin Goldfish Vs. Koi
- How Big Are They?
- How Long Do They Live?
- Temperament and Activity Level
- What Are Good Tank Mates?
- What Do They Eat?
- Tank Requirements
- Water Quality
- Aquarium Maintenance
- How To Set Up Your Fish Tank
- Health and Disease
- Availability
- Is the Shubunkin Goldfish Right for You?
- How the Shubunkin Goldfish Compares to Similar Species
- Closing Thoughts
- The Reality of Keeping Shubunkin Goldfish: The
What Most Care Guides Get Wrong About Shubunkin Goldfish
The biggest mistake I see with shubunkin goldfishs is underestimating their aggression. Guides will label them “semi-aggressive” and move on. In practice, that label doesn’t tell you much. Tank layout, stocking density, and territory management all play a huge role in whether these fish coexist or constantly fight. Tank size is another area where most guides get it wrong. The minimum listed on most care sheets is exactly that, a minimum. For long-term success, especially if you’re keeping a group, I always recommend going at least one size up from whatever the guide suggests. Finally, diet gets oversimplified. Pellets alone won’t cut it. In my 25+ years keeping fish, I’ve found that variety in diet directly affects color, growth, and overall vitality. Include frozen foods, quality pellets, and occasional vegetable matter for the best results.
The Reality of Keeping Shubunkin Goldfish: The
Tank size requirements are not negotiable. A single fancy goldfish needs at minimum 20 gallons. A single-tail variety like a comet needs 40 gallons minimum, and realistically belongs in a pond. The one-gallon-per-inch rule does not apply to goldfish.
Filtration needs to be oversized. Goldfish produce more ammonia than tropical fish of the same size. Your filter should be rated for at least double your actual tank volume. A 40-gallon tank with goldfish needs filtration rated for 75 to 100 gallons.
They are cold-water fish that do not need heaters. Goldfish thrive between 65 and 72 degrees. Putting them in a heated tropical tank stresses them and shortens their lifespan. Room temperature water is fine for most homes.
Biggest Mistake New Owners Make
Putting a goldfish in a small bowl or tank without filtration. Goldfish produce massive amounts of waste. Without proper filtration, ammonia levels spike within days and the fish suffers organ damage long before it shows visible symptoms.
Expert Take
The best goldfish keepers I know run heavy filtration and do large weekly water changes. There is no shortcut or trick that replaces those two fundamentals.
A Brief Overview Of The Shubunkin
| Scientific Name | Carassius auratus |
| Common Name (Species) | Shubunkin Goldfish |
| Family | Cyprinidae |
| Origin | Japan |
| Diet | Omnivore |
| Care Level | Easy |
| Activity | Active, social |
| Lifespan | Up to 30 years |
| Temperment | Peaceful |
| Tank Level | All Areas |
| Minimum Tank Size | 75 Gallons |
| Temperature Range | 65 – 72 Degrees F |
| KH | 150 |
| pH Range | 6.0. 8.0 |
| Filtration/Flow Rate | Moderate |
| Water Type | Freshwater |
| Breeding | Egg-layers, Easy to breed |
| Compatibility | Peace commuity species |
| Ok, For Planted Tanks? | With Research |
Classification
| Taxonomic Rank | Classification |
|---|---|
| Common Name | Shubunkin Goldfish |
| Scientific Name | Carassius auratus |
| Order | Cypriniformes |
| Family | Cyprinidae |
| Genus | Carassius |
| Species | C. Auratus |
Origins and Habitat
Shubunkin Goldfish are also known as Calico Goldfish, meaning multicolored. As a type of Goldfish (Carassius auratus), theyโre descendants from the wild carp living in Asia today and were first bred in Japan. The Shubunkin earns its name from a town in Japan called Shubuta where they were first bred. These fish were first brought into the West in 1882 by James Meehan, who was a curator at the London Zoo.
As for habitat, Shubunkins are a member of the Cyprinidae family, which means they like to live in slow rivers, lakes, ditches, or ponds. In Asia, fish kept in ponds have a habitat moderately decorated with plastic plants, driftwood, and rocks.
What Does They Look Like?

The Shubunkin is similar to the Common Goldfish and the Comet Goldfish in appearance and is crossbred from these two, as well as the Calico Telescope Eye Goldfish. They have nacreous scales which are pearly in appearance and look like a mix between transparent and metallic scales.
The Calico Goldfish has overlapping patches of white, gray, red, black, and blue colors that is seen on their long, flowing tail fins. The most valued color of a Shubukin is blue, and this is also the rarest color. These fish are heavily spotted as well.
, people divide Shubunkins into three different types:
London
The London Shubunkin goldfish has a slender body and shorter tails that are more rounded, similar to the Common Goldfish.
American
The American Shubunkin is also known as the Japanese Shubunkin. An American Shubunkin has longer fins and a sharper fork tail, and looks more like Comet Goldfish than the other types.
Bristol
The Bristol Shubunkin is quite rare and has a B-shaped tail that stands out. Also, the Bristol Shubunkin be longer and broader than other types.
Shubunkin Goldfish Vs. Koi
Below is a good reference video from J Lo on the difference between Shubunkin Goldfish and Koi. As you can see, the Shubunkin compliments as Koi with it’s varied color and fin shapes. They look amazing together in a pond! In some Koi keeping circles, the Shubunkin is often label a “poor man’s Koi”. The way I see it, they remind me of Butterfly Koi and allow you to keep the purity of the Koi line if you do not want to stick to Traditional Koi.
How Big Are They?
One common feature among the Goldfish freshwater species is that they grow based on their surroundings., Shubunkin Goldfish reach a size between 6. 12 inches, but if you keep them in a small space, theyโll be smaller.ย
These are excellent pond fish as well, since they can grow up to 14. 18 inches if they have enough room, and there have even been reports of them reaching lengths beyond 18 inches.
How Long Do They Live?
Depending on their environment, Shubunkin Goldfish are hardy fish and have a lifespan of 10. 15 years with proper care.
Shubunkins that are kept in ponds live even longer since they have lots of space to explore and live a happy life. Some even have a lifespan of up to 30 years.
Temperament and Activity Level
These fish are super social and like to hang out in groups. Theyโll likely spend their days exploring their aquarium or pond, meaning that theyโre very active. Like most Goldfish species, theyโre fast swimmers and do well paired with other fast-swimming fish.
They also like to eat whatever they can get their hands (or mouths) on, and they often scavenge for food at the bottom of the tank. Therefore, the only type of aggression you might encounter with Shubunkins is that theyโre quick to steal food.
What Are Good Tank Mates?
While they can live alone, the Shubunkin thrives in tanks with other fish, and they make a good addition to community tanks. Some species suit them better than others, however.
Good Tank Mates
These quick swimmers pair well with other fast-moving fish that thrive in cooler waters as the Shubunkin does. They do well with other species of Goldfish as well as many other species. Here are some suggestions for fish to pair with your Shubunkin Goldfish:
Fish Species to Avoid (Bad Tank Mates)
Since Shubunkin Goldfish will steal as much food as they can manage, itโs best not to pair them with slow-moving and shy species, as they might have a hard time getting enough nutrition.
For the more experienced fish owner, you can pair your Shubunkin with slower swimmers as well. Just make sure to watch and feed your fish at different times, starting with the fast ones and then moving onto the slower ones.
Shubunkin Goldfish donโt pair well with aggressive fish such as Tiger Barbs or Cichlids since they donโt like fighting. They also do not pair well with Fancy Goldfish because they are very fast compared to them. Fancy goldfish will struggle to eat enough with an athletic Shubunkin in the tank or pond.
Finally, some tropical fish species might not be the best mates for Shubunkin, since they prefer cooler waters.
What Do They Eat?
Shubunkins are omnivores and eat almost anything you drop into the water. But for them to get all the nutrition they need, itโs best to feed them high-quality dried food such as flakes and pellets.
Another great thing is that these fish are scavengers and will eat up whatever they can find at the bottom of the tank, such as plant material and detritus. Just they might uproot live plants while theyโre at it.
What About Live Foods?
Like all types of Goldfish, Shubunkin feed on insects and small crustaceans. Some live or frozen foods to feed them occasionally include Daphnia, blood worms, tubifex worms, krill, and brine shrimp.
How Much and How Often to Feed
You should feed your Goldfish twice a day and give them as much as they can eat for two minutes each time. For the everyday staple meal, pellets or flakes are your best choices. Occasionally, they should also get a treat in the form of live or frozen food.
Once or twice a week, you can also give them some fresh vegetables from your kitchen, such as spinach, lettuce, or cucumber, but peel and blanch them first.
Tank Requirements

While the Goldfish Shubunkin is rather easy to take care of, you need to consider the type of tank itโs going to live in as well as how to decorate it.
Tank Size
There is lots of misleading information out there in regards to keeping a Goldfish. While your Shubunkin Goldfish will stay alive in a tank thatโs 15. 20 gallons, itโs too small for them to live a healthy life. Instead, you should invest in an aquarium thatโs with a minimum tank size of 75 gallons to give them room to swim and search for food.
As your fish will grow depending on how much space it has to move around in, the bigger the tank, the better. Shubunkins live the happiest in wide-open spaces where they can roam around and are great to keep as pond fish.
If you add more fish to your aquarium, remember to increase the tank size by 10. 15 gallons per new member. A 75-gallon tank should only keep one Shubunkin Goldfish.
Tank or Pond Setup
Since this Goldfish type lives in slow-moving rivers or lakes, you want to make sure that your tank has low to moderate water movement. Speaking, a water filtration system provides enough movement in the tank. You can invest in some air stones if you wish to help keep the oxygen at reasonable levels.
Shubunkins arenโt picky, and most substrate works with this fish. The best choice is medium-sized gravel since theyโll be able to sift through this material and look for food. You can also opt for a bare bottom pond, a favorite setup for Koi Pond setups and for ease of cleaning.
You can also invest in some underwater live plants for a more natural-looking habitat. This fish is a quick eater, so it’s likely to unroot almost anything you plant. Your best bet here is fast-growing plants such as Hornwort, Java Fern, and Anacharis.
In terms of other decorations, Shubunkins arenโt picky and wonโt mind plastic or silicone plants. The most important thing for them is to have a good amount of swimming space, so you can use some driftwood or rocks in your tank or pond but keep it minimal.
Finally, you need to provide a sufficient amount of light. This will help your Shubunkin Goldfish maintain its natural sleeping pattern. There are many tanks on the market that have built-in LED lights with different settings for day and night that is a good investment.
Water Quality
Filtration
The Shubunkin is a messy fish and has a high waste load, which means that you need a good filtration system in your pond or tank. Your best bet is a filter with biological media. Without a filter, nitrate and ammonia levels in the water might reach unhealthy levels. However, also remember make that water change frequent and clean the tank or pond.
When picking a filter, look for one that can clean all the water in your tank or pond. If it lacks in this aspect, youโll end up with unfiltered water. I recommend a high quality power filter or opt for a canister filter.
Water Parameters
One good thing with the Goldfish species is that it tolerates changes in water conditions much better than more sensitive tropical fish, for example. They can even survive in temperatures a few degrees over freezing, which is why they make such great pond fish. However, you should invest in a water heater if you plan on keeping your Shubunkins in an outdoor pond during the winter.
Here are the ideal water parameters for Shubunkins:
- Water temperature: 65. 72 degrees Fahrenheit
- Hardness: 5. 19 dH
- pH levels: 6.0. 8.0
Aquarium Maintenance

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Since Goldfish are messy types of fish, you need to clean out their tank more frequently than many other species. Keeping your aquarium clean is the most efficient way to prevent your Shubunkin from getting sick or developing any fish diseases.
Every one to two weeks, you should clean your aquarium. First, wipe off the outside of the tank with an ammonia-free cleaner and a cloth, then shake the plants inside the aquarium to get rid of debris. Also, scrape the inside of the glass to remove algae, and then take a break for 15 minutes. Finally, siphon the substrate to further remove debris and then perform a 25 percent water change.
Test Water Conditions
You should check the pH level, hardness, and water temperature frequently, especially when setting up your tank and after changing the water. Make sure that the levels are within the spectrums stated in the section above.
Other things you need to test are the levels of ammonia, nitrite, and nitrate. For Shubunkin Goldfish, the levels should be the following:
- Ammonia: 0 ppm.
- Nitrite: 0 ppm.
- Nitrate: <40 ppm.
In order to test the water conditions, invest in an aquarium water test kit. A good rule is to test the water conditions on a monthly basis. At the same time, make sure you also change the filter media.
How To Set Up Your Fish Tank
Before your Shubunkin moves into its new home, you need to set up the tank. Make sure you have a clean aquarium with the proper water conditions and temperature for your fish to start with, and itโll be easier to tweak them later.
How To Set Up a Fish Tank
Follow these seven steps to set up the fish tank for your Shubunkin Goldfish.
1. Clean the Tank
First of all, wipe off any dust with a damp cloth, never use any household chemicals or old cleaning equipment to clean the inside of your tank. If you have an old aquarium that needs some extra cleaning, you can use vinegar to dissolve dirt.
2. Position the Tank
Now itโs time to position your tank. Itโs best to put it into place before filling it with water since itโll get heavier. Make sure that itโs out of direct sunlight and placed on a stable stand. It should also be level.
3. Fill Tank With Substrate and Water
After this, itโs time to fill the tank with the substrate. For the Shubunkin, use medium-size gravel and rinse it with cold water before you fill the aquarium.
Follow a ratio of 1 pound of substrate per gallon of water for a 1-inch thick bed, or 2 pounds of substrate per gallon of water for one thatโs 2 inches thick. For a 75-gallon minimum tank size, this means 75. 150 pounds of substrate. For 125 gallons, youโll need 150. 300 pounds.
When the gravel is inside the tank, fill it with water. Shubunkin Goldfish are freshwater fish, so youโll need to use fresh water. A tip to prevent the running water from spreading out the gravel is to place a bowl or saucer at the bottom of the tank and pour water onto it. After filling the aquarium, add dechlorinator to the water, following the instructions on the bottle.
4. Install the Filter
You can choose to use an external or internal filter, but we recommend an external one since it filters water more efficiently and has more space for media. The best choice for Shubunkins is to use a filter with biological media.
Set up depends on the brand, so look at the instructions. You place it within the sand below the tank. Before you plug it in, fill it with water to start the filtering process. When you install it, make sure that the inlet and outlet tubes are straight so that water flows through them easily.
5. Decorate It
When youโre done with the basic setup, itโs time to decorate the tank. Remember that Shubunkins like to have lots of space to swim but that some plants and other items are okay to add. Rinse every item before you place it into the tank to prevent dirty water.
Most plants are fine being buried in the gravel, but some species such as Java Fern need to be attached to some driftwood first and then placed into the aquarium.
6. Cycle the Tank
Before adding any fish, you need to cycle the water in the tank to build up bacteria in your biofilter that can convert ammonia into nitrites and then nitrites into nitrates. This is to prevent toxins from building up in the water.
Simply add some ammonia into the tank (I recommend using Dr. Tim’s Ammonia), following the instructions on the bottle. You need to check the levels of these substances frequently. When they reach 0 ppm, your tank is fully cycled. This might take a few weeks, so prepare your aquarium well in advance. For bacteria in a bottle, check out Fritz Turbo start.
Fritz Turbo Start is known in the industry as the fastest acting nitrifying bacteria you can purchase. This 700 version is specialized for freshwater tank and has my highest recommendation
7. Add Your Fish
Now your Shubunkin Goldfish is ready to move in. Since fish is sensitive to changes in water conditions, you want to acclimatize your Goldfish by slowly adding half a cup of water from the tank into its bag and wait for 5 minutes between adding another half a cup.
When youโve acclimatized your Shubunkin, use a net to transfer it to the tank. Discard the remaining water in the sink and observe your new friend for the next 24 hours to make sure it eats and settles in well.
If you opt to quarantine your fish (which I recommend), consider quarantine for 30 days in a separate tank.
Health and Disease
While this is a hardy fish, that doesnโt mean that itโs immune to freshwater fish diseases. So, letโs talk about how you recognize a healthy as well as an unhealthy Shubunkin.
Signs of Good Health
A healthy Shubunkin swims constantly and eats regularly. It looks shiny, its colors are vibrant, and the scales are intact and not damaged. They also get along well with their tank mates and frequently explore the tank, digging and scavenging for food.
Signs of Ill Health
Some signs to be wary of include:
- White spots on its scales.
- Swimming sideways or just floating around without swimming actively.
- Only staying close to the surface or the bottom of the tank.
- Staying in one corner.
- Not eating.
- Constipation.
- Injured scales.
- Rubbing its scales against tank walls and plants.
Common Health Issues and Treatment
Ich is one of the most common diseases for freshwater fish. This is a parasite that appears as white spots on fish scales, and if left untreated, the white wounds can lead to bacterial infections and kill the fish. If you notice your Shubukin rubbing itself against surfaces and developing white spots, take it to a vet immediately. There are several products you can add to your tank to treat Ich.
Swim bladder disease is another issue Shubunkin Goldfish can suffer from. Signs include swimming sideways, staying close to the surface or the bottom of the tank, or swimming in strange patterns. A home remedy against swim bladder disease is to feed your fish blanched peas, but your best bet is to seek help from a professional.
Other diseases that can affect this Goldfish type include fin rot and skin flukes that other parasites or fungus cause. If your Shubunkin shows signs of ill health, seek advice from a vet.
Breeding
Shubunkin spawns during the spring and to start this process, move the fish into a separate breeding tank and drop the temperature to 60 degrees Fahrenheit. Then warm the water in the breeding tank by 2. 3 degrees F every day until the temperature reaches 72 degrees F.
Youโll see the malesโ colors begin to intensify, and theyโll start chasing the females. After a few days, theyโll push the females into the plants, where theyโll lay up to 10,000 eggs. After a few hours, spawning is done, and you need to remove the adult fish from the tank, or theyโll eat the eggs.
After 4. 7 days, the eggs will hatch. Proceed to feed the baby fish with fry food until they reach 1-inch, and then put them into the adult tank.
Are Your They Male or Female?
You probably wonโt be able to tell males and females apart until they reach maturity. During the breeding seasons, males will develop breeding tubercles on their gills and heads, which will look like white spines. The females will get rounder bellies when eggs develop.
Availability
Youโll find Shubunkin Goldfish available to buy at almost any pet store, fish supply shop, and even online. Not everyone has access to a quality local fish store. For those who do not have a good local fish store, check out my best places to buy fish online post. To save you time, for Shubunkins, I would recommend NextDayKoi for purchasing the quality quality Shubunkins.
What You Need To Buy
- Fish tank
- Medium-sized gravel
- Filtering system with biological media
- Dried fish food flakes
- Fast-growing plants
- De-chlorinator
- Ammonia and Bacteria
- Aquarium water test kit
Is the Shubunkin Goldfish Right for You?
Before you add a shubunkin goldfish to your tank, it’s worth asking whether this species actually fits your setup and your goals. Here’s a quick breakdown to help you decide.
This species is a good fit if:
- You have a large enough tank to manage territories. Cramped conditions amplify aggression.
- You’re comfortable managing aggression through stocking ratios, line of sight breaks, and tank layout.
- You can commit to regular water changes. These fish produce more waste than many smaller species.
- You’re not planning a peaceful community tank. Shubunkin Goldfishs need tank mates that can hold their own.
- You enjoy watching active, interactive fish. Cichlids have personality that smaller species simply don’t match.
- You have backup plans. Sometimes a particular fish just doesn’t work out, and you need a way to rehome it.
- You’re feeding a varied, high-quality diet. Color and health depend on nutrition.
If most of those points line up with your setup, the shubunkin goldfish is worth serious consideration. If several don’t, it’s better to choose a species that matches your tank now rather than trying to make it work.
How the Shubunkin Goldfish Compares to Similar Species
Want a pond fish? Get comets or shubunkins. Want an indoor aquarium goldfish? Get fancies and plan for a 40-gallon minimum. Want a low-maintenance pet? Get a betta instead.
Choosing between similar species is tricky. Here’s how the shubunkin goldfish stacks up against some common alternatives.
The shubunkin goldfish occupies a specific niche in the aquarium hobby, and direct comparisons really depend on what you’re looking for. In my experience, the most common question people ask is whether they should choose the shubunkin goldfish or something similar that’s more widely available. The answer comes down to three things: tank size, water parameters, and what other fish you’re keeping. If your setup matches what the shubunkin goldfish needs, it’s hard to beat. If not, there are alternatives worth exploring.
Closing Thoughts
The Shubunkin Goldfish is an active, beautiful, and hardy species that socializes well with other freshwater fish and is kept in outdoor ponds or indoor tanks. Theyโll make a great addition to your aquarium as long as you give it enough space to swim around and maintain healthy water conditions in the tank.





















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