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Izumo Nankin Goldfish: Pictures, Size, Care, Tank Setup, & More

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By Lindsey Stanton

izumo nankin goldfish swimming in the tank

Izumo Nankin Goldfish hail from the Shizuoka Prefecture in Japan and while they are relatively common in their home country, they are rare and very difficult to get hold of outside Japan. They are brightly colored and when viewed from the top, they have a distinct triangular shape. This breed is placid and can be kept with others of its species or with other types of placid goldfish.

Size: Up to 6 inches long
Lifespan: 10–15 years
Similar Breeds: Ryukin Goldfish, Eggfish Goldfish
Suitable for: All fish owners
Temperament: Placid, calm

Izumo Nankin Goldfish are rare outside Japan, and it is expensive to have them shipped abroad, which makes them very rare. However, in Japan, they are quite common and there are breed fancier associations and clubs dedicated to Nankin Goldfish. If you can get hold of them, they are placid fish that tend to do well with other placid goldfish species. They are colorful, too, and they have a unique triangular appearance when viewed from above.

They do like to dig around in their substrate, so avoid fine gravel, and they will nibble on plants, as well as eat the flakes or pellets you feed them. If you can source Izumo Nanking Goldfish, they do make a great addition to the tank, and they are considered suitable for novice keepers.

Izumo Nankin Breed Characteristics

Ease of Care

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Izumo Nankin Goldfish Cost

Izumo Nankin Goldfish are very rare except in Japan. However, when they are available, they are inexpensive goldfish and can generally be bought for between $10 and $20. However, their rarity prohibits most people from owning them. It may be possible to bring them back over from Japan but this would require specialist equipment for the journey, while having them shipped over is prohibitively expensive. If you know somebody that keeps Izumo Nankin, or can find somebody that does, it may be possible to convince them to breed the fish.

This species is not particularly demanding, other than requiring quite a large tank. But, you won’t need to provide special lighting, so the cost of setting up the tank is relatively low.

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

Sociability of the Izumo Nankin Goldfish

The Izumo Nankin Goldfish is a pleasant little goldfish that, like most species of goldfish, is placid and calm. This means that it can be kept with other fish, although you will have to adjust the size of the tank accordingly, and you should avoid housing the Izumo Nankin with fish that might attack it.

Do These Fish Make Good Pets?

The white body and red or orange blotches mean that the Izumo Nankin Goldfish is quite easy to spot in a tank, and while they are quite slow swimmers, they do like to dig up the substrate and swim in between any plants, which means they can be fun to watch.

Does This Fish Make a Good Tankmate?

The Izumo Nankin Goldfish is an ideal tankmate for other placid fish. It won’t pick on smaller fish and won’t even fight back if it is attacked by another fish. This means that it is highly suited to sharing its habitat with other placid and non-aggressive species of Goldfish.

Carassius auratus Goldfish_gunungkawi_shutterstock
Image Credit: gunungkawi, Shutterstock

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Care Guide & Tank Set Up

Other than needing quite a lot of space, the Izumo Nankin Goldfish is not too demanding a tank dweller. Offer between 20 and 30 gallons of tank capacity for the first Izumo with an additional 10 gallons for every other fish.

Water Quality, pH, & Temperature

The Izumo Nankin Goldfish needs a water temperature between 43°F and 53°F as well as a pH between 6.5 and 7. Specific gravity also needs to be maintained between 1.008 and 1.009 but these aren’t too demanding for a tank. The water will need cleaning regularly, especially because this species likes to dig around in substrate looking for food, which can cause dust clouds.


Because the species likes to dig up its gravel and search for food, you do need to be careful when choosing a substrate. Avoid fine gravel or your fish could pick up the pieces and eat them by mistake, making them quite ill. River rocks or larger gravel can make a good substrate for Izumo Nankin.


Like most goldfish, the Izumo Nankin likes to nibble at plants. You can add some plants because this is a good way of supplementing their flake or pellet diet, but you need to choose plants that are safe. You might also find that the breed attempts to nibble at plastic and synthetic plants so avoid these.

Credit: susemeyer0815, Pixabay


The Izumo Nankin does not need excessive amounts of light but it does need some, and natural light is generally better. Place the tank near a window so that it gets some natural sunlight, but avoid putting it directly in the window where it will get the bright glare of the sun and the water can become dirty.


The Izumo Nankin’s tank will need a filter to help clear out algae and dirt, and also to help manage the dust clouds that are kicked up from the substrate. As well as this, you will need to do a partial water change every couple of weeks.

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Things to Know When Owning an Izumo Nankin Goldfish:

The Izumo Nankin is quite easy to care for, although it does require a reasonable amount of tank space. You don’t need artificial lighting and the water requirements should be easy to hit, making it a decent choice for novice keepers. With that said, you do need to ensure that the Goldfish’s requirements are properly met.

Food & Diet Requirements

Feeding the Izumo Nankin is also quite easy as the fish will take commercial fish flakes or pellets. You should carefully monitor the amount you are feeding, however, and be sure to follow the feeding guidelines on the packaging to avoid over-feeding your fish.

Size & Growth Rate

Young Izumo Nankins grow quickly in the first few months and will grow about an inch a year once they get a little older, reaching a maximum length of around 6 inches. Several factors can affect the overall growth of the Izumo Nankin, including the amount you feed and the general conditions in the tank.

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


The Izumo Nankin is a white or silver fish with red or orange blotches. It is triangular and has a small head and no dorsal fin. There aren’t any known variations of the species, but the color and appearance of the fish can vary from one to the next. An ideal coloring is considered one that has an equal amount of white and red, but some are almost entirely white, and others are entirely red or orange.

Lifespan and Health Conditions

With a lifespan of up to 14 years, the Izumo Nankin Goldfish is especially susceptible to poor water conditions, so changing the water regularly and monitoring water conditions to ensure they are ideal is important.

Serious Conditions
  • None
Minor Conditions
  • Skin Flukes
  • Parasites
  • Fungal Infections
  • Bacterial Infections
  • Water sensitivity

goldfish divider Male vs Female

Female Goldfish are usually thicker, rounder, and longer than male Goldfish. Although aggression is rare in this species, it is the male that is most likely to show territorial tendencies, but this really is unusual in Izumo Nankin Goldfish.

3 Little-Known Facts About Izumo Nankin Goldfish

1. They Are Very Rare Outside Japan

The Izumo Nankin hails from the Shizuoka Prefecture of Japan. While the species is quite common there, it is very difficult to find outside its home region. If you do find a source of Izumo Nankins, the species is surprisingly inexpensive and can make a great tank inhabitant as it is placid and colorful.

2. Breeders Clubs Exist In Japan

While the species is rare outside Japan, it is popular in its homeland, where the Central Nankin Lovers Association and other groups celebrate these and other Nankin varieties.

3. They Need Space

Although they are quite easy to care for and don’t have too many demands other than clean water, Izumo Nankin Goldfish do need quite a lot of space. A single one should be given 30 gallons, and for every additional Izumo Nankin in the tank, you will need to give an additional 10 gallons.

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Izumo Nankin Goldfish are very rare outside Japan, but they are pretty goldfish that are placid and calm. They need clean water, which means regular water changes will be necessary, and you will need at least a 30-gallon tank, but their diet is easy and their water requirements are also easy to meet.

As long as you can commit to the space and a fortnightly water change, and you don’t have any bully fish in the tank, they are a good choice of tank inhabitants as long as you can find a supplier or know a breeder.

Featured Image Credit: natural.sound_.design, Shutterstock

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