Shubunkin Fish: Your Guide to Easy Care and Keeping

Shubunkin (朱文金, red brocade) — is one of artificially bred ornamental species of tank goldfish (Carassius gibelio forma auratus) that has transparent scales and fancy coloring.

Habitat in the wild

The shubunkin is a type of goldfish that belongs to the Cyprinidae family, which is commonly known as the minnow or carp family. Shubunkins are a variety of single-tailed goldfish and are known for their striking colors and calico pattern, which includes patches of red, orange, blue, black, and white. They are a popular choice for freshwater aquariums and outdoor ponds due to their hardiness and attractive appearance.

As mentioned, the shubunkin is a member of the Cyprinidae family, which is one of the largest fish families, consisting of various species of minnows, carps, and other closely related fish. This family includes well-known fish species like common goldfish (Carassius auratus), koi (Cyprinus rubrofuscus), rosy barb (Puntius conchonius), and many others.

The history of the shubunkin goldfish can be traced back to the early 20th century in Japan. The exact origins of the shubunkin are not entirely clear, but it is believed to be a result of selective breeding involving several different varieties of goldfish.

The shubunkin is a cross between the Calico Telescope Eye goldfish and the common goldfish, both of which are single-tailed goldfish. The Calico Telescope Eye contributed the calico color pattern, which includes patches of red, orange, blue, black, and white. The common goldfish, on the other hand, brought the streamlined body shape and single tail.

The name “Shubunkin” is of Japanese origin and roughly translates to “red brocade,” which is a reference to the vibrant and colorful calico pattern exhibited by these fish.

The shubunkin gained popularity and recognition in Japan, and by the 1920s, it was introduced to other parts of the world, including Europe and the United States. It quickly became a popular and sought-after variety of goldfish among aquarium hobbyists due to its striking appearance and hardy nature.

This ‘goldfish’ breed became popular in England and at the beginning of 1920 a new kind of the breed was developed, it was called London shubunkin. In 1934 Bristol Aquarist Society bred another species named Bristol shubunkin as well as published the breed standard. It defined the fish as the one with elongated body shape and well developed tail fin. A bit later the third type appeared – American Shubunkin which have a slimmer body shape, pointed tail fins, and longer finnage all around. However, nowadays London shubunkin is far more spread and it is most likely that this is the one you will see on sale.

Selective breeding continued to refine the shubunkin’s colors and patterns, resulting in the development of high-quality specimens with beautiful and intricate markings. Over time, the shubunkin’s popularity continued to grow, and it remains a popular choice for both indoor aquariums and outdoor ponds.

Today, the shubunkin is widely available in pet stores and through specialized breeders, and its beauty and adaptability continue to make it a beloved addition to freshwater aquariums and water gardens worldwide.

Common NameShubunkin Goldfish
Scientific NameCarassius auratus (variant)
FamilyCyprinidae (Minnow or Carp Family)
OriginJapan (early 20th century)
Size6 to 8 inches (15 to 20 centimeters) in length
Lifespan10 to 15 years (can live longer with proper care)
Body ShapeSlender and streamlined body with a single tail
ColorCalico pattern with patches of red, orange, blue, black, and white
TemperamentGenerally peaceful and sociable, suitable for community tanks
Tank/pond requirementsNeeds ample space to swim, at least 20 gallons per fish in an aquarium, and a large pond for outdoor setups
Water conditionsPrefers a pH range of 7.0 to 8.4 and a temperature of 65°F to 75°F (18°C to 24°C)
DietOmnivorous, will eat commercial flakes, pellets, and live/frozen foods
BehaviorActive and energetic, spends time exploring and foraging for food
HardyResilient and can tolerate a range of water conditions, making them suitable for beginners
BreedingCan breed in captivity, spawning occurs in warmer water with the presence of plants or spawning mops
Tank/pond compatibilityCan coexist with other peaceful freshwater fish, but avoid keeping them with aggressive or fin-nipping species



Shubunkin has elongated, flattened from sides body like the one of its wild ancestor – common carp. What makes the fish different from other goldfish is its body – it is short, wide and rounded. The fins are long and always open, the tail fin is claw-ended.

The shape of the body and fins resembles the ordinary goldfish. What makes shubunkin different, is its transparent scales due to which the fish is called ‘scaleless goldfish’ and its bright fancy coloring. Therefore such a coloring of the fish got the name ‘calico’.

The most rarely encountered are the species with bluish body and dark red, brown, yellow and black spots scattered around it. This fish breeds true.


If the fish dwells in a tank, its length is about 15-20 cm (6-8 in), though some sources report that they reach a length of 9 to 18 inches (23 to 46 cm). The latter is quite possible, though only for the fish in ponds and provided with very high feeding. It’s essential to provide Shubunkins with a spacious and well-maintained environment, as this can positively impact their growth and overall health. Inadequate living conditions, such as small tanks or overcrowded ponds, can stunt their growth and lead to health problems. To allow your shubunkin goldfish to reach its full potential size, provide it with a suitable and adequately sized aquarium or pond with proper filtration and regular water changes.


The lifespan of a shubunkin goldfish typically ranges from 10 to 15 years, but with proper care and a healthy environment, they can live even longer. Some well-cared-for shubunkins have been known to live up to 20 years or more. The key to extending their lifespan lies in providing them with a suitable and well-maintained environment, a balanced and nutritious diet, and regular monitoring of their health.

Difficulties in keeping

This gorgeous fish is one of the most enduring goldfish breed variations. They are simple in care, not demanding in terms of either feeding or tank conditions. This is an active fish and it is good for community tanks.

Care and keeping in a tank

As we’ve already mentioned shubunkin is one of the most undemanding fish in terms of keeping. In Japan which is its birthplace, the fish is kept in ponds, though the temperature may be quite low there in winter.

Tank size

The tank size or aquarium size for shubunkin goldfish should be a minimum of 20 gallons per fish. However, it’s important to note that shubunkins are active and energetic fish that can grow quite large, reaching lengths of 6 to 8 inches (15 to 20 centimeters) or even more. As they grow, they will require more space to swim and thrive.

For this reason, it is highly recommended to provide a larger tank if possible. A 30-gallon tank or larger is preferable for a single shubunkin, and if you plan to keep more than one, you should increase the tank size accordingly. If you are considering multiple shubunkins, it’s best to have at least 40 to 50 gallons of water volume to accommodate their size and activity levels comfortably.

In general, the bigger the tank, the better it is for your fish, as it allows for better water quality, more swimming space, and reduces the need for frequent water changes. A larger tank also provides opportunities for creating a more diverse and interesting aquatic environment with hiding spots and decorations.

If you have limited space or resources and cannot provide a large tank, you might want to consider keeping Sshubunkins in an outdoor pond, as they are well-suited for such setups. Outdoor ponds can offer a natural environment with ample space, which can be beneficial for the health and well-being of your shubunkin goldfish.

Tank decor

Creating a well-decorated tank for your shubunkin goldfish not only enhances their living environment but also provides them with mental stimulation and places to explore. Here are some tank decor ideas suitable for shubunkins:

  1. Substrate: Use smooth gravel or sand as the tank’s substrate. Avoid using sharp or rough gravel that could injure your fish. It’s better to use sand or large gravels as a tank bottom substrate. Goldfish digs the bottom all the time and quite often they swallow large substrate grains and die because of this.
  2. Plants: Live aquatic plants not only add visual appeal but also provide hiding spots and oxygenate the water. Hardy and fast-growing plants like Anubias, Java Fern, and Hornwort are good choices. Be aware that shubunkins might nibble on live plants, so choose plants that are less likely to be eaten. At that shubunkin likes digging the tank bottom substrate, scattering dirt and digging out tank plants. Therefore, you should put there only plants with strong roots that will survive at such conditions.
  3. Driftwood and Rocks: Adding driftwood and rocks can create hiding places for your shubunkins and add a natural look to the tank. Ensure that any rocks used are smooth and do not have sharp edges.
  4. Bubbler or Air Stones: Air stones or bubble walls not only improve oxygenation but also create visual interest with bubbles rising from the bottom of the tank.

Remember to arrange the decorations in a way that does not obstruct the flow of water or create barriers that might lead to territorial disputes among the fish. Additionally, regular maintenance of the tank, including cleaning the decorations and checking for any sharp edges or rough surfaces, is essential to keep your shubunkins safe and healthy.

Water parameters

As for the tank water parameters, they may vary greatly, but these are the optimal ones:

  1. Temperature: 65°F to 75°F (18°C to 24°C)
    Shubunkins are cold-water fish and thrive in temperatures that are slightly cooler than tropical fish. Avoid extreme temperature fluctuations, as they can stress the fish.
  2. pH Level: 7.0 to 8.4
    Shubunkins can tolerate a wide pH range, but keeping the water slightly alkaline (pH above 7.0) is generally preferred.
  3. Ammonia and Nitrite: 0 ppm
    Ammonia and nitrite are toxic to fish. Regularly test the water and ensure these levels are consistently at 0 ppm.
  4. Nitrate: Below 40 ppm (ideally 20 ppm or lower)
    Nitrate is a byproduct of the nitrogen cycle in an aquarium. While Shubunkins can tolerate moderate levels of nitrate, it’s best to keep it as low as possible to ensure optimal health.
  5. Hardness: 5 to 20 dGH (degrees of general hardness)
    Shubunkins can adapt to a range of water hardness levels, but keeping it within this range is generally suitable.

Remember, these water parameters are guidelines, and slight variations can be tolerated by healthy and well-acclimated fish. However, sudden and significant changes in water conditions can stress or harm the fish. It’s crucial to use a reliable water test kit to monitor the water quality regularly and perform water changes as needed to maintain stable and suitable conditions.

For outdoor pond setups, shubunkins are hardy fish and can tolerate a broader range of water conditions. However, maintaining stable and good water quality is still essential for their health and longevity. Regular water changes, proper filtration, and attention to the overall pond ecosystem will contribute to the well-being of the shubunkins in a pond environment.


Shubunkin is an omnivorous fish, it will eat all types of frozen, live and artificial food. The diet should contain 50-70% of vegetable component and 30-50% of protein one. To keep the tank water clean feed the fish with high quality food (flakes or pellets).

The main thing is not to overfeed the fish, since it is prone to intestinal obstruction. It is dangerous to overfeed the fish with a bloodworm since it causes flatulence, the fish looses its balance and dies as a result.

Tank mates

Do shubunkins eat other fish? Shubunkin goldfish are generally peaceful and not aggressive towards other fish. They are social creatures and prefer to coexist peacefully with other fish of similar temperament and size. In most cases, shubunkins will not eat or attack other fish in the same tank or pond. In general, shubunkins are well-suited for community aquariums and peaceful outdoor ponds with other similarly sized and peaceful fish.

Shubunkin goldfish are generally peaceful and can coexist with various tank mates that share similar temperaments and environmental requirements. When choosing tank mates for shubunkins, it’s essential to consider their size, behavior, and water preferences to ensure a harmonious and stress-free community.

Here are some suitable tank mates for shubunkin goldfish:

  1. Common Goldfish (Carassius auratus): Common goldfish are close relatives of shubunkins and can be good tank mates as they have similar size and temperament.
  2. Comet Goldfish: Comets are another type of single-tailed goldfish that can get along well with shubunkins. They have a similar body shape and are generally peaceful.
  3. Ryukin Goldfish: Ryukins have a distinctive hump behind their head and can coexist peacefully with shubunkins, especially in a spacious tank or pond.
  4. Rosy Barbs (Puntius conchonius): Rosy Barbs are hardy and peaceful fish that can thrive alongside Shubunkins in a community setting.
  5. Weather Loaches (Misgurnus anguillicaudatus): Weather Loaches are bottom-dwelling fish known for their playful behavior and ability to tolerate cooler temperatures.
  6. Kuhli Loaches (Pangio kuhlii): These small, peaceful, and nocturnal loaches can be interesting additions to the tank.

Remember, when keeping tank mates with shubunkins, it’s essential to provide enough space to accommodate all the fish comfortably. Shubunkins can grow quite large, so a larger tank or pond is ideal to prevent overcrowding. Regularly monitor the behavior and health of all fish and be prepared to separate any individuals that show signs of aggression or stress.

Gender differences: male vs female

Determining the sex of shubunkin goldfish can be a bit challenging, especially when they are young. However, as they mature, there are some subtle differences in physical characteristics that can help identify males and females. It’s essential to observe multiple individuals over time to increase your accuracy in sexing them. Here are some general differences between male and female shubunkin goldfish:

  1. Size: In some cases, females can be slightly larger and rounder than males, especially when they are full of eggs.
  2. Body Shape: Females tend to have a rounder and plumper body shape, especially when they are carrying eggs. Males, on the other hand, may have a slimmer and more streamlined appearance.
  3. Vent Shape: The vent, located just in front of the anal fin, is a small opening that is used for breeding and waste elimination. In mature females, the vent may appear rounder and slightly more prominent, while in males, it may be more slender and elongated.
  4. Fins: In some cases, males may have slightly longer and more pointed pectoral fins compared to females. However, this characteristic can be subtle and may not be reliable for sexing.
  5. Breeding Behavior: During the breeding season, males may show increased chasing and courtship behavior, trying to entice the females to lay eggs.

It’s important to note that these differences can be subtle, and there is no guaranteed method to sex shubunkin goldfish accurately until they reach sexual maturity. Additionally, some individual fish may not exhibit all the typical characteristics of their sex, making it more challenging to determine their gender.

If you are specifically interested in breeding shubunkin goldfish, it’s best to keep a group of young fish and observe their development over time. As they reach maturity and breeding behavior becomes more apparent, you will have a better chance of identifying the males and females in the group.