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How Big Do Shubunkin Goldfish Grow To? Factors, Diet & FAQ

Brooke Billingsley

By Brooke Billingsley

Shubunkin Goldfish

Goldfish are extremely popular pet fish. There are multiple reasons for this, but the primary reasons are that they are generally inexpensive, hardy, and easy to acquire. There are a lot of varieties of goldfish, with many of them increasing in popularity. One variety of goldfish that is typically easy to acquire and inexpensive compared to other specialty goldfish is the Shubunkin. A fully grown Shubunkin can grow anywhere between 8 to 14 inches.

Shubunkins are beautiful and unique goldfish that are well-loved for their calico appearance, which makes them really stand out, especially in a tank full of orange or black goldies. Don’t run out and buy one right away, though. It’s important to know what to expect from this fish before bringing it home.

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Facts About Shubunkins

Shubunkins are a slim-bodied goldfish variety, so they can keep up with other fast-moving goldfish varieties, like Commons and Comets. In fact, Shubunkins often have longer, more athletic bodies than other slim-bodied varieties. They are just as hardy as Common and Comet goldfish varieties.

These goldfish are defined by their attractive coloration. They feature a mixture of silvery white, red, blue, grey, and black, and they have nacreous scales. Nacreous refers to a mother-of-pearl type of finish to the scales. The amount of each color present on Shubunkins varies between individuals, and each fish sports a different pattern from others.

Shubunkins are a Japanese goldfish variety, even though many varieties of goldfish originated in China. Sometime around 1900, Yoshigoro Akiyama crossed Common, Comet, and Calico Telescope Eye goldfish, and the resulting offspring of these crosses were the original Shubunkins.

There are three categories of Shubunkin goldfish. The American Shubunkin has a long, slim body with long fins and forked, pointed tail fins. The London Shubunkin is a stouter Shubunkin variety with shorter, more rounded fins, giving them a similar appearance to the Common goldfish. Bristol Shubunkins have long, broad bodies, and while they have large fins all over, their tail fins are extremely large and heart-shaped. The American Shubunkin is the most common variety in American pet stores and fish shops.

Shubunkins Size and Growth Chart

Close up of a shubunkin goldfish swimming
Image Credit by: tim allen photo, Shutterstock

The following growth chart defines the general growth patterns of the American Shubunkin. There are many factors that can influence the size of a goldfish, from nutrition to water quality to tank space, so the rules of growth aren’t hard and fast with any goldfish variety.

Age Length Range
1 month 0.9 – 1 inches
6 months 1 – 2 inches
12 months 3 – 3.25 inches
18 months 3.5 – 4.5 inches
2 years 4 – 5.25 inches
2.5 years 4.5 – 6 inches
3 years 5 – 6.5 inches
4 years 6 – 7.75 inches
6 years 7 – 10.75 inches
8 years 8 – 12 inches
10+ years 8 – 14 inches

When Does a Shubunkin Stop Growing?

Depending on their environment, goldfish can continue to grow beyond 10 years of age. When stunting occurs, though, a goldfish may not even grow beyond a few inches in length, regardless of age.

In ideal circumstances, a Shubunkin can be expected to continue to grow for at least 10 years, with some continuing to grow past that age. In general, Shubunkins don’t exceed 14 inches in length, but it isn’t unheard of for slim-bodied goldfish to exceed this length.

Factors Affecting the Size of Shubunkins

Image Credit by: Michelle Jo, Wikimedia Commons

As mentioned above, there are a variety of factors that can influence the size of a Shubunkin goldfish. One phenomenon that can occur in goldfish is stunting. When water quality, diet, or available space isn’t up to par, goldfish growth can become stunted, which refers to a hormonal growth stunting that occurs when a goldfish is kept in a chronic stress situation. Shubunkins are capable of experiencing stunting, just like all varieties of goldfish.

Other factors that can make or break the growth of a Shubunkin include diet and nutrition, water quality, and genetics. Possibly the least understood factor is how genetics can impact the growth and maximum size of a goldfish.

Ideal Diet for Maintaining a Healthy Weight

Shubunkins should be provided with a high-quality diet with plenty of variety. In general, pellet foods are higher quality than flake foods, and they usually have a lower likelihood of fouling the water. For maximum nutrition, a Shubunkin should have a diet that offers multiple omnivorous options.

A rotation of more than one high-quality fish food can provide variety and interest for a goldfish, while the addition of vegetables, fruits, and treats can support health and provide enrichment. Goldfish are grazers that will eat throughout the day, so providing them with something to snack on can keep them from eating the plants in the tank. Leafy greens, cucumber, herbs, bananas, bloodworms, baby brine shrimp, and other foods can be provided for treats and enrichment.

How to Measure Your Shubunkins

There isn’t a perfectly accurate way to measure your Shubunkin without taking it out of the water. While this isn’t ideal, goldfish have a labyrinth organ that allows them to breathe air for a period of time. Gently removing them from the water and using a soft tape measure is easiest to do when there is a second set of hands to help. Goldfish can be quite slippery, so it’s easy to drop them if they wiggle.

If taking your Shubunkin out of the water isn’t something you’re comfortable with, you can use a tape measure or ruler to measure your fish while they’re in the water. Providing them with something interesting to examine might get them to hold still long enough for a mostly accurate length.

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Shubunkins are beautiful goldfish that are second to none when it comes to their interesting colors and patterns. They are athletic fish that can keep up with the other slim-bodied goldies, so you can feel comfortable keeping your Shubunkin in a home with other fish.

Goldfish can reach or exceed 14 inches in length, though, so it’s important that you consider the adult size of your goldfish before bringing it home. Many goldfish live artificially shortened lives due to their owners being unprepared for the long-term needs of these fish.

Featured Image Credit by: slowmotiongli, Shutterstock

Brooke Billingsley

Authored by

Brooke Billingsley spent nine years as a veterinary assistant before becoming a human nurse in 2013. She resides in Arkansas with her boyfriend of five years. She loves all animals and currently shares a home with three dogs, two cats, five fish, and two snails. She has a soft spot for special needs animals and has a three-legged senior dog and an internet famous cat with acromegaly and cerebellar hypoplasia. Fish keeping...Read more

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