Izumo Nankin Goldfish: Best 10 Farming Benefit

Izumo Nankin Goldfish

Izumo Nankin Goldfish is a fish species that humans deliberately bred for their bright gold-colored scales. They are a popular pet fish and a special ornamental item in Japan and the United States.

The Izumo goldfish has a long history of domestication. It was originally bred in Shizuoka Prefecture, Japan, though it is also commonly found in the United States.

Dutch goldfish breeder Anton van Leeuwenhoek first bred it in the 17th century. The nearby city of Kawasaki registered Izumo goldfish as its official symbol in 1971 and still celebrates them annually.

Izumo Nankin Goldfish Characteristics

The most distinguishable characteristic of the Izumo goldfish is its bright yellow color. It has red or white eyes, and odd-numbered scales are strongly concave while even-numbered scales are convex.

It grows to an average of three to four inches in length but can reach up to around six inches in some cases. The fish has a single caudal fin with an extended fin base and a lunate tail shape resembling an umbrella when swimming.

The tail fin is supported by tendons visible on the dorsal and caudal fins. Unlike other goldfish, the Izumos do not have scales on their fins but rather a smooth epithelium layer.

Izumo Nankin Goldfish History

The Izumo goldfish developed independently from other goldfish species and was first domesticated in the 17th century by Dutch fish breeder Anton van Leeuwenhoek.

The fish was originally bred in Shizuoka Prefecture, Japan, and then transplanted to other parts. The legend goes that the breed once inhabited a lake in Nankin City.

Now part of Kawasaki City, which is named after the goldfish. Kawasaki City celebrated its annual Izumo Goldfish Festival from 1972 to 2009.

They have also passed a resolution naming the fish as Kawasaki’s cultural symbol, acknowledging it for its history as a source of local pride in the city.

                                  Review the full breed profile of this fish in the following table.

Name   Izumo Nankin Goldfish
Other Names    None
Breed Purpose Ornamental, pet
Special Notes    Very beautiful, caring is very difficult, not constitutionally strong, available only in its native country, the species is generally unknown outside its native range
Breeding Method           Artificial
Climate Tolerance           Native climates
Body Color         Many
Rarity   Common
Availability         Japan

The appearance of Izumo Nankin Goldfish

Izumo’s have a long history of being associated with gold, beginning in medieval Japan. The goldfish is an ornamental fish and was even bred for use in the tea ceremony.

The fish can grow to an average length of three to four inches but sometimes grow up to six inches. They have a single caudal fin and long fins that extend out from the body, creating a resemblance similar to an umbrella.

Izumo Nankin Goldfish Care

Izumo goldfish prefer cool temperatures and frequent changes in water. The fish can be kept in a cold room, with the water temperature ranging from 45 to 53 degrees Fahrenheit. Under normal circumstances, their tank should be replaced every two weeks.

The aquarium should include a filter to keep the water clean and algae-free. Their diet should consist of flakes and protein-based pellets found at pet stores.

Izumo Nankin Goldfish Health

Izumo’s are particularly sensitive to water conditions and can die if the water is not changed frequently.

They are also prone to skin tumors and erythrocytic kidney disease, which causes the fish’s eyes to change color and its scales to drop off. The tumors and kidney disease can be treated through medications or surgery.

Izumo Nankin Goldfish Reproduction

The fish can be bred by carefully separating the males from the females. The males have a longer, more pointed caudal fin and a brighter color.

Izumo’s are known for their toughness and have been bred in captivity for over 130 years with relatively few complaints.

They are also naturally fertile, rearing up to 4,000 fries per breeding cycle. More than 70 percent of them survive to adulthood without any intervention at all.

Aquarium setup

A mature tank is recommended for large fish such as the Izumo. The size of the tank will depend on the number of fish being kept in it, but a minimum of 10 gallons per goldfish is recommended. Aquariums with a 20-gallon capacity should be used for optimal goldfish care.

The goldfish aquarium should include an aquarium filter to provide oxygenated water for the fish and help keep the water clean. The filters should be changed every two to four weeks, depending on how well they maintain the water clear.

Water pH

The specific gravity of the water should be kept between 1.008 and 1.009 so that it is soft enough to keep the fish’s gills moist but not so high as to cause it stress. The pH level should be between 6.5 and 7, depending on the quality of the water being used.

Farming Benefit of Izumo Nankin Goldfish

Here are The Best 10 Farming Benefit of Izumo Nankin Goldfish

1. The breeding of The Izumo Nankin Goldfish can achieve a high success rate.

2. The breeding of The Izumo Nankin Goldfish is one of the most productive varieties in the world and has served as a model for other varieties to be bred.

3. The breeding of Izumo Nankin Goldfish is divided into two phases, first breeding through self-fertilization, then selecting the best eggs and raising them in pairs until they are ready to be sold.

4. The eggs of the Izumo Nankin Goldfish are difficult to select, and the survival rate of the newborns is also low.

5. The breeding of wild goldfish is a long and arduous task, as it can take up to ten years for them to mature.

6. The breeding of wild goldfish requires greater skill than that needed for basic domestication and specialized knowledge.

7. Goldfish are not hardy in captivity and require special care to survive.

8. The Izumo Nankin Goldfish is known for its small size, but they are very efficient breeders even at this small size.

9. The large body of the Izumo Nankin Goldfish gives it a large amount of energy that is difficult to consume, so it tends to be less active than other varieties.

10. The Izumo Nankin Goldfish are known for their high fertility and ability to live with other goldfish varieties.


The Izumo Nankin Goldfish is known for its small size, but they are very efficient breeders even at this small size. They have been bred in captivity for over 130 years with few complaints.

Other than the cultural significance of the fish as Kawasaki’s symbol, there is also a long-held belief that the fish’s longfin can protect it from being attacked by other animals.

The Izumo Nankin Goldfishes are fairly difficult to keep and require intensive care to survive. Thanks for reading this article.

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