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Watonai Goldfish: Care Guide, Varieties, Lifespan & More (with Pictures)

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By Lindsey Stanton

white orange sabao goldfish


Goldfish are available in over a hundred breeds, each bearing its own unique characteristics. Many goldfish enthusiasts enjoy caring for goldfish of all varieties, finding favorites in appearance and temperament over time. Some breeds of goldfish are exceptionally rare, maybe none rarer than the Watonai goldfish. True Watonais are believed to be extinct, but in recent years, some enthusiasts have begun recreating the breed. Modern Watonais are beautiful, but also difficult to find and expensive. Is the fancy, hardy Watonai goldfish a good match for you?

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Quick Facts about Watonai Goldfish

Species Name: Carassius auratus auratus
Family: Cyprinidae
Care Level: Moderate
Temperature: 65–78˚F
Temperament: Peaceful, social
Color Form: Self-colored, bicolor, tricolor, calico, sarasa
Lifespan: 15 years average
Size: 10–12” or more
Diet: Omnivorous
Minimum Tank Size: 30 gallons
Tank Set-Up: Freshwater; filtration; smooth substrate (optional); heater (optional indoors, necessary in ponds)
Compatibility: Other goldfish varieties (fancy), koi, other peaceful fish and invertebrates
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Watonai Goldfish Overview

The Watonai goldfish, also known as the Long-Bodied Ribbontail, is a rare breed believed to have originated as a cross between Ryukins and Wakins. They were developed near the beginning of the 20th century and are believed to have gone extinct sometime after the mid-century mark. These goldfish were prized for their fan-like tails, streamlined bodies, and hardiness.

Some modern goldfish breeders have begun cross-breeding Ryukins and Wakins, creating the modern Watonai goldfish. Although not of the original Watonai stock, these goldfish are a developing breed that hits all the high points of Watonai’s appearance and temperament. It is possible that the original Watonais were a result of cross-breeding between Comets and Wakins, but modern Watonais are a result of the Ryukin and Wakin cross.

It is unfortunate that the breed died out and needed to be recreated, but one benefit to being able to start the breed over is that we now have a better understanding of the role that genetics plays in health, appearance, and temperament. As the breed continues developing, this will likely result in healthier stock and potentially new, distinctive color combinations. Having to restart Watonais from scratch has driven up the cost of the few available fish. They are difficult to find and can cost hundreds of dollars to purchase.

How Much Do Watonai Goldfish Cost?

Due to their relative rarity, Watonai goldfish can be expensive. At the low end, they usually cost around $60–75. At the high end, they can cost up to hundreds of dollars. These prices do not include the cost of shipping a live fish or travel expenses to pick the fish up if they are unable to be shipped due to weather or shipping restrictions.aquarium plant divider

Typical Behavior & Temperament

Watonai goldfish, like most goldfish varieties, are peaceful. They are social and curious, often exploring their environment and enjoying activities like scavenging. They are fast for fancy goldfish but are slower than common varieties like Comets and their predecessors, Wakins. They are playful but have been known to nip the tails of other fish, so may do best alone or with fish that will be able to outswim them or hide if needed.

Appearance & Varieties

Watonais are a fancy variety of goldfish featuring a long, flowing caudal fin. When viewed from above, this fin takes a butterfly-like shape. Watonais were bred from Ryukins, which are a fancy variety of goldfish with a shoulder hump, and Wakins, which are considered a common variety of goldfish due to their long, narrow body even though they do have long double-tails like fancy varieties.

Watonais have slightly egg-shaped bodies when viewed from the side, much like Ryukins. However, their bodies are long and streamlined like Wakins when viewed from above. They have a long fantail like Wakins, but the tail is usually much longer in Watonais. They are an elegant variety of goldfish, beautiful in tanks and ponds alike.

Watonais come in a variety of colors, including red, white, blue, orange, yellow, and black. They are often self-colored red, white, or orange but also can be bicolored or tricolored. They can be Sarasa, which is a combination of red and white, and calico, which is a combination of multiple colors and usually includes blue.aquarium plant divider

How to Take Care of Watonai Goldfish

Habitat, Tank Conditions & Setup

Tank/Aquarium Size:

Like most goldfish, Watonais prefer tanks that are long and narrow as opposed to tall or rounded. They enjoy having space to swim longer distances as opposed to having to swim shorter laps or circles. With proper filtration, they can be kept in smaller tanks, but ideally, they should be in 30 gallons or more. These goldfish can reach up to a foot or more in length, so this should be considered when researching tanks for Watonais.

Water Temperature and pH:

Watonais are extremely hardy, possibly the hardiest of all fancy variety goldfish. They are comfortable in a temperature range similar to that of common goldfish, but they can happily live in water as cool as 60˚F and as warm as 78˚F. They are sensitive to temperature fluctuations, so this should be taken into consideration. In indoor tanks, they do not require a heater, but if kept in outdoor ponds, they will likely need a heater to maintain the temperature in cooler weather. Due to their hardy nature, Watonais can safely live in pH levels between 6.0 and 8.0.


Tank substrate is not necessary for Watonais, but it can provide enrichment and encourage scavenging. Since their fins are delicate, it is best to provide aquarium sand or smooth pebbles, or river rocks as substrate.


Watonais will eat or uproot many plants but do appreciate plants like Java Ferns, Hornwort, Anubias, and Amazon Swords. They are unlikely to eat these plants but may uproot them. They also enjoy moss balls, which can be a nice enrichment item in their environment, but goldfish have been known to shred moss balls as well.


Watonais do not require tank lights but do enjoy light for 8–12 hours per day. This light can be provided with an over-tank light as well as natural light from windows or artificial light from overhead lights. Providing light and dark periods to mimic natural day/night cycles helps maintain fish health and happiness.


Like most goldfish, Watonais do contribute a large amount of waste to their environment. Filtration should be adequate to filter around double the tank size or more per hour. However, Watonais do not like strong currents and will actively avoid them, so creating filtration while blocking strong water currents is best.

If you're a new or even experienced goldfish owner who is having issues understanding the intricacies of water filtration, or just wants a bit more detailed information on it, we recommend that you check out our best-selling book, The Truth About Goldfish. 

The Truth About Goldfish New Edition

It covers everything about creating the most ideal tank setup and more!

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Are Watonai Goldfish Good Tank Mates?

Watonais are peaceful, social fish and can make a great addition to community tanks. However, tankmates should be large enough that the Watonai cannot eat them or they should be provided with plenty of hiding places. These fish also make great pond residents and can be paired with similar-sized koi. Watonais have been known to nip at other fish, so if this happens, the Watonai may need to be housed alone.

Watonais make good tankmates for most peaceful community fish. There have been reports of Plecostomus fish sucking slime coat off goldfish and damaging scales and fins, so they may not make good tankmates for Watonais.

It is strongly recommended to quarantine a new Watonai before introducing it to the tank or pond. Even coming from the highest quality breeding facilities, they can still introduce diseases or parasites into the new tank.

What to Feed Your Watonai Goldfish

Watonais can be fed a high-quality pellet or flake food, like Saki-Hikari Fancy Goldfish Food. Once or twice weekly, this meal can be replaced with brine shrimp, bloodworms, daphnia, or other treats. They are true omnivores, so they appreciate having fresh plants, fruits, and vegetables available at all times.

There are a wide variety of foods that are safe for goldfish to eat, including greens like tender salad greens, kale, and arugula, as well as zucchini, cucumber, apples, oranges, carrots, and peas. Fresh foods should be steamed or blanched prior to serving to ease digestion, and veggie clips can be used to decrease mess. They can also be fed frozen foods or gel-based foods, like Repashy Super Gold pre-mix.

Keeping Your Watonai Goldfish Healthy

Like many fancy goldfish varieties, Watonais are prone to swim bladder disease. Sinking foods can help decrease swim bladder problems as well as provide enrichment through scavenging. These goldfish are almost as hardy as common varieties of goldfish, and with proper care and tank maintenance, they should stay healthy. If needed, you may try to find a fish veterinarian in your area. This can be difficult since many vets do not care for fish, but agricultural veterinarians are often able to care for fish if needed. The American Association of Fish Veterinarians’ website has a vet finding tool available to help find a vet near you as well.


During the breeding season, it may be necessary to separate males and females if the males become too aggressive in chasing the females. Males will chase females to stimulate them to release eggs but can cause females injury if allowed to become too aggressive in their pursuits. If you are attempting to breed these fish, a spawning mop will help collect the fertilized eggs. Switching to a fish food specifically formulated for breeding health will ensure the fish are healthy enough to produce successful clutches of eggs. Once the eggs hatch, the fry are fair game for any fish in the environment, so it is best to move them to a separate tank.aquarium plant divider

Are Watonai Goldfish Suitable For Your Aquarium?

Watonai goldfish are beautiful and unique, and their rarity makes them an excellent conversation piece in a tank or pond. Their expense can be off-putting, though, and to provide them the best life possible, they will need high-quality food, regular tank or pond maintenance, and enough space to grow. The long life expectancy and hardiness of Watonais should be considered when deciding on a Watonai for your tank or pond. While they usually reach up to a foot long, Wakins can reach up to 19 inches or more, so it is possible Watonais can reach these extreme lengths as well. They are a long-term commitment, but with proper care, they can be an enriching part of your life and family.

Featured Image Credit: Pavaphon Supanantananont, Shutterstock

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