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Izumo Nankin Goldfish: Care Guide, Varieties & Lifespan (with Pictures)

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By Lindsey Stanton


The Izumo Nankin Goldfish is a rare breed from southwestern Japan. In Japan, it is rare. Outside of Japan, it is even harder to source. For this reason, this breed is hardly ever found in the states. You have to know a breeder or travel to Japan to get the fish (and then successfully transport it back to the states).

This breed has many fanciers in its native country. There are many clubs dedicated to this Goldfish breed, including the Central Nankin Lovers Association.

These fish are known for their red and white coloration. When viewed from above, their body resembles a triangle.aquarium plant divider

Quick Facts about the Izumo Nankin Goldfish

Species Name: Izumo Nankin Goldfish
Family: Goldfish
Care Level: Difficult
Temperature: 68 to 74º F
Temperament: Peaceful
Color Form: Red and white
Lifespan: 10–15 years
Size: 21 to 22 cm
Diet: Plants
Minimum Tank Size: 10 gallons
Tank Set-Up: Large and open
Compatibility: Peaceful; compatible with species that won’t eat them
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The Izumo Nankin is a rare species of goldfish. They are hardly ever seen outside of southwest Japan. They are not as hardy as other species, so they are difficult to ship. This is largely why they are so rare—it is difficult to purchase them because they will very likely die in transit. There are currently very few breeders in the United States. Instead, you will have to go to Japan and transport one back with you.

Generally, these fish are very similar to other goldfish. They do not require significant amounts of care, but they do require that you clean their tank very regularly. They are very dirty fish, as they will dig in their gravel and generally just make a mess. They don’t need many plants or anything of that sort for this reason. They will likely just dig them up.

These fish are very peaceful, which makes them compatible with many different species. They are not hard to pair with other fish. The only requirement is that the other fish is also peaceful. Otherwise, they could injure the goldfish. Generally, they do fine with other goldfish and similar peaceful fish. You may not want to put them with small fish, as they can accidentally injure them.

izumo nankin goldfish on blue background
Image Credit: Ko-Thongtawat, Shutterstock

How Much Do Izumo Nankin Goldfish Costs?

If you’re in Japan, you can purchase one of these fish for only a few dollars. A quick online search will show you many Japanese sites that are selling these fish for around $10. However, the problem is getting the fish to you. You will need to purchase transportation, which is likely going to be very expensive. You need very good transportation to ensure that this fish will survive from Japan. That is going to cost you quite a bit.

Alternatively, you could travel to Japan yourself for the fish, but this is also going to be significantly expensive.

Typical Behavior & Temperament

These fish are very similar to other Goldfish. They are peaceful and not incredibly smart. They will eat plants, so they don’t do well in planted aquariums. Furthermore, they like to dig, so they will dig up plants often. They kick up dirt and such as well, so their tanks need to be cleaned more than you may expect.

These fish are quite active. This means they will kick up more dirt and make more of a mess than other fish. They also need a larger tank, as they need plenty of room to move around.

izumo nankin goldfish swimming in the tank
Image Credit: natural.sound_.design, Shutterstock

Appearance & Varieties

There are no varieties of this goldfish. They all come in a similar coloration. They are a red and white goldfish. Typically, their coloration is encouraged through the use of vinegar. With a special vinegar mixture, the red will turn white with minimum harm to the fish. Many people will do this to encourage more white on their fish.

Some of them are completely white, while others are completely red. A decent mixture of these two colors is usually what is most sought after. All-red males may be more expensive, though, as this usually leads to more red on their offspring. Females tend to be a bit whiter, though this is not always the case.

These fish do not have a dorsal fin, which is similar to other varieties of goldfish. They have a ranchu-like tail that possesses partial fusion. Sometimes, they are confused for ranchu goldfish for this reason.

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From diagnosing illnesses and providing correct treatments to ensuring your goldies are happy with their setup and your maintenance, this book brings our blog to life in color and will help you to be the best goldfishkeeper you can be. 

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How to Take Care of a Izumo Nankin Goldfish

Habitat, Tank Conditions & Setup

These fish are very sensitive. This is largely why they are so rare. They are extremely suspectable to very simple changes in their environment. Everything needs to be exactly right for them to thrive.

They need a decently large tank, mostly because they are so dirty. They like to stir up dirty and are very active, so they need plenty of room to move around. Aeration is also important, as they are quite large fish. Double-filtration is recommended.

These fish are not sensitive to their substrate. They do like to dig, though, so be prepared for the substrate to get messed up. They will eat plants, so be sure anything you put in their tank is okay for them to eat.

They are cold-water fish, so their tank should be kept around 70 degrees Fahrenheit. This is extremely important, as these fish are very sensitive to their tank’s temperature. They are not extremely hardy like other Goldfish varieties, so you need to ensure that their tank always stays at the correct temperature.

Are Izumo Nankin Goldfish Good Tank Mates?

Yes. They are pretty laidback, peaceful fish. They don’t typically bother other fish and are not aggressive. They will eat plants, so don’t put anything valuable in their tank with them. They also like to dig. Their large size can bother some smaller, burrowing animals. We generally do not recommend any fish that burrows in the substrate as a tank mate.

Smaller fish may also not be a good option. This isn’t because they are aggressive. However, the smaller fish may be injured by these boisterous fish.

They are perfectly fine with other Goldfish as long as they have plenty of room.

In general, you have to be more worried about the other fish bothering this Goldfish than the Goldfish harming the other fish. They are sensitive, so small fish that may bite at their fins are not recommended in the least.

surprised izumo nankin goldfish up close
Image Credit: Noheaphotos, Shutterstock

What to Feed Your IzumoNankin Goldfish?

Typically, any high-quality Goldfish food is a good option. You should avoid low-quality options, like those you find at chain pet stores. These are typically full of fillers, which is the last thing you want to give your rare, sensitive Goldfish.

Instead, you need to purchase your food from a trusted source.

On top of a commercial food, you can also feed your Goldfish peas, bloodworms, brine fish, ghost shrimp, and a variety of other options. These can be used as treats or to improve your fish’s overall diet. Generally, these things do not include all the nutrients your fish needs. For this reason, you need to feed them mostly a commercial, complete diet.

Keeping Your Izumo Nankin Goldfish Healthy

To keep this fish healthy, you will need to change their water regularly. They are fairly dirty fish, but they are also quite sensitive to this dirt. For this reason, you need to change their water regularly. In a large tank, once a week, partial water changes may be enough. Frequent, partial water changes are always the best option, as they do not stress out the fish as much as complete water changes.

You also have to keep track of the temperature of the water, as they are sensitive to temperature changes. Aeration and filtration are also important. This goes hand-and-hand with cleaning the tank regularly. These fish are dirty, so you need to use a double filter.

They also do well with plants that they can eat. They won’t eat a whole plant, but they do like to nibble on the leaves. For this reason, we recommend planting hardy, edible plants with them. Also, be sure to feed them a suitable food. If you don’t feed them high-quality food, you can shorten their lifespan.

Breeding Izumo Nankin Goldfish

These fish are not terribly difficult to breed. They are pretty docile and peaceful, even when they are breeding. You will need to make a spawning mop, though this is very easy to do from home. They lay their eggs in this “mop”, which then needs to be removed from the regular tank and put into a hatching tank.

Most eggs hatch within a week. It depends on the temperature. Once all are hatched, you can take out the spawning mop when they are swimming freely.

You can also hand breed these fish, which is a bit more involved. However, it is a faster way to ensure that the two exact fish you want to breed do breed. Generally, to do this, you need to press on the male’s abdomen to distribute the milt into a small breeding bowl. Then, gently press on the female to distribute the eggs into the same bowl.

After a short wait, the eggs will be fertilized. They will stick to the basin, which you can then rinse very gently with water. Then, fill it up with water and place it near a window with an air pump. Once again, the eggs will hatch in at least a week.aquarium plant divider

Are Izumo Nunkin Goldfish Suitable for Your Aquarium?

The Izumo Nunkin Goldfish is a beautiful goldfish – if you can get it. They are extremely rare, and you can usually only find them in Japan. Generally, these are pretty docile fish, which makes them great pets. They are suitable with many different tankmates.

They are a bit sensitive, though, so you really need to keep track of their temperature. You also have to keep their tank very clean, as they are typically quite dirty.

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