Goldfish are a perennially popular pet with both adults and kids alike, and Shubunkins with their variegated colors are easily the favorite variety of these super-cute, beginner-friendly fish. But there’s more to the mysterious Shubunkin than just pretty colors!
In this article, we take a closer look at the Shubunkin goldfish, including explaining how to care for these beautiful fish.
Shubunkin goldfish usually have a variegated or speckled coloration, but what makes these fish stand out from the crowd is their rare blue color.
Shubunkins were developed in Japan in the early 1900s. You may also find Shubunkins advertised for sale as Calico goldfish. Calicos are multicolored fishes, having yellow, red, orange, black, purple, white, brown, and gray, on top of a blue base color. Other common names for the Shubunkin include Harlequin goldfish, Speckled goldfish, and Coronation Fish.
There are two forms of Shubunkin goldfish, namely the Bristol Shubunkin and the London Shubunkin, but it is usually the more common London Shubunkin that you find in pet stores.
All types of Shubunkins are extremely hardy and easy to keep, making them perfect for beginners. Also, Shubies, as their fans fondly call them, will eat whatever you offer them, and they’re peaceful community fish.
Modern goldfish (Carassius auratus auratus) are genetically descended from several species of wild carp that are found in Central Asia, where they live in slow-moving waters, such as lakes, ponds, rivers, and ditches, feeding on plant matter, insects, and small crustaceans.
The goldfish that you see for sale in pet stores today were developed in China way back in the 1400s. In the 1500s, the Chinese were trading goldfish with Japan. The goldfish arrived in Europe in the 1600s and in the U.S. by the 1800s. Much of the breeding of goldfish was carried out in Japan, and it’s thought that the Shubunkin goldfish was created here. All the goldfish that you see in pet stores are captive-bred. There are no wild populations of this artificially created species.
It’s incredible to think that the glorious colors, shapes, and sizes of the pet goldfish that we enjoy today took centuries of painstaking breeding to develop.
Shubunkins have elongated, flat bodies with a wide, short head. The fish’s body tapers from its belly and back to the base of the forked tail fin. The edge of the dorsal fin is concave and typically carried erect.
Shubunkins have an average lifespan of up to 15 years, although goldfish have been recorded as living for up to 20 years in a well-maintained tank or pond.
The London Shubunkin has the short, deep body of traditional, common goldfish types with similar fin shapes. This variety of Shubunkin was developed in the U.K. around 80 years ago. These fish come in a wide variety of color mixes and do well in a large tank or pond.
The Bristol Shubunkin has a slender body that is similar to the Comet goldfish, and it has a huge tail fin that is wide and forked with well-rounded lobes. Sometimes, the weight of the fish’s spectacular tail can hamper its ability to swim.
When it comes to the fish’s size at maturity, that depends to some extent on the environment in which the fish is kept. In a smaller tank of up to 15 gallons, a goldfish will grow to measure around five inches. However, in a larger tank, the fish will grow larger, typically up to about six inches. That being said, if you keep your goldfish in a very large aquarium or in an outdoor pond, your Shubunkin could reach 18 inches in length.
Shubunkin goldfish have a blue background adorned with a random mixture of colors, including orange, red, white, silver, purple, black, and gray. The blue color is pretty unusual and sought after, and is created because the fish’s body is black underneath its skin.
Ease of care
Shubunkin goldfish are extremely hardy and easy to care for, which makes them the perfect choice for a beginner hobbyist. You can keep goldfish in an aquarium or a pond. However, if you’re thinking of keeping a fish pond, do be sure to install protective netting so that your fish don’t fall victim to predatory birds or your neighbor’s cat!
Tank-kept fishes don’t need a heater, as long as the room doesn’t experience extremes of temperature. Like all goldfish, the Shubunkin is a dirty fish, producing vast amounts of waste every week. For that reason, you’ll need to install a very efficient filtration system, as well as carrying out weekly partial water changes and vacuuming the substrate to get rid of solid waste and general detritus.
How to care for Shubunkin goldfish
As we’ve already mentioned, Shubunkins are very easy to look after. Here’s what you need to know if you’re thinking of taking on one of these beauties.
Tank size and shape
The key to keeping your fish happy and healthy is providing them with a well-maintained aquarium that’s large enough to comfortably accommodate the fish.
The size of the tank that you choose depends on how many fish you want to keep. Goldfish produce a lot of waste, and they need plenty of oxygen too. That means you’ll need to use a very good filtration system that can cope with the bioload produced by the fish, and the flow rate should be pretty decent too so that the water is well-oxygenated. Of course, you will need to carry out 30% water changes every week, as well as vacuuming the substrate to remove detritus, solid waste, and uneaten food.
The absolute minimum tank size for a single Shubunkin goldfish is 15 gallons. That said, goldfish should not be kept alone, as they are very social animals that do best when kept in a group. So, start off with a 20 to 30-gallon tank, increasing the size by 10 gallons per extra fish.
Remember that your tiny inch-long juvenile fish will quickly grow to reach up to six inches, so buy a large tank, to begin with, or be prepared to upscale your pet’s accommodation when necessary. Overstocking the tank causes growth stunting, so don’t be tempted to buy too many fish.
Always choose a tank that is long rather than deep. That provides plenty of surface area and, therefore, lots of oxygen. If you do go for a round aquarium, don’t fill it with water right to the top, as that reduces the surface area.
Shubunkins need plenty of swimming space, so be careful that you don’t overcrowd the tank with decorations and ornaments. A gravel substrate is a good choice, as the fish like to rummage through it looking for scraps of food, and it’s also relatively easy to vacuum. Any decorations that you choose should have no sharp edges that could injure your fish.
Goldfish love plants! Unfortunately, that means that they love to rip them to pieces and uproot them too. So, rather than including live planting, you should try using silk plants instead. Plastic plants should be avoided, as they can be sharp and potentially dangerous for your fish.
As mentioned above, you’ll need a very efficient filtration system to keep the water clean and safe for your fish. However, the flow shouldn’t be too strong, so buffer the current with decoration or planting if necessary so that the fish don’t get buffeted around too much.
Goldfish are coldwater fish so, you won’t need a heater for your aquarium. Ideally, you want to keep the room temperature and water temperature between 65° and 72° Fahrenheit. Although Shubunkins are just about the hardiest variety of goldfish you can get, they don’t tolerate quick temperature drops, so you will need to monitor the temperature in the room where you keep their tank, especially in wintertime.
When it comes to pH, again, the Shubunkin can tolerate a wide range between 6.0 and 8.0 pH with a water hardness of between 5 and 19 dGH.
Diet and nutrition
Shubunkin goldfish are not fussy when it comes to food!
These fish are omnivores, meaning that they eat a mixture of plant matter and meaty foods. The ideal diet for your fish should be a staple of goldfish flake or pellets, freeze-dried food, and frozen foods such as brine shrimp, bloodworms, daphnia, and tubifex worms. To add variety to your pet’s diet and to guard against conditions such as constipation that can affect goldfish, offer your fish some blanched zucchini or peas once a week or so.
Although goldfish will happily gobble up live food, we recommend that you don’t use that, as it can be a source of parasites that could make your fish sick.
Ideally, you should feed your fish two to three times per day. Offer your pet just enough food to last him a few minutes but no more. Overfeeding is a common source of sickness in goldfish, so make sure that you don’t give your fish too much of a good thing!
Goldfish are peaceful, sociable creatures that are happiest when kept in a group of the same species. You can introduce other coldwater species, too, such as White Cloud Minnows, Rosy barbs, and Gold barbs. However, when the goldfish grow to their adult size, they do have a habit of eating anything that will fit into their mouths, so small fish may be viewed as lunch! Also, invertebrates such as shrimp should not be kept with goldfish, as they will most likely be eaten.
You can breed goldfish in a home aquarium and definitely in an outdoor pond. The breeding season for goldfish begins in spring when the water warms up. Males develop white prickles (tubercles) across their head and gill covers, and female fish appear fatter because they are carrying eggs. Outside of the breeding season, it’s difficult to sex goldfish, although males are generally smaller and slimmer than females.
Shubunkins, like all goldfish, are egg layers, often spawning best when kept in groups, especially outside in ponds.
To encourage spawning in the aquarium, you must try to replicate the same conditions that the fish will enjoy in the wild environment. So, you will need to raise the temperature in the tank to around 68° Fahrenheit. If you’re setting up a separate spawning tank, it should be at least 20 gallons, and your breeding fish must be free from disease and in good condition.
Separate the male and female fish for a few weeks before you try to breed them to increase their interest in spawning, and then introduce both sexes together. Provide plenty of lush planting and spawning mops on which the fish can scatter their eggs.
Induce spawning by reducing the temperature slowly to around 60° Fahrenheit, and then gradually increase the temperature to between 68° and 74° Fahrenheit at a rate of around 3° Fahrenheit every day until spawning starts. You should also feed your Shubunkins lots of live worms and brine shrimp to bring them into breeding condition. Keep making 25% water changes every day to keep the water in the tank pristine.
Egg laying and fry
The male fish will chase the female around the tank until she lays her eggs, which stick to plant leaves or to the spawning mop where they will be fertilized by the male. As soon as the eggs are laid, you must remove both the parents, or they will eat the eggs. The spawning process can take up to three hours, and as many as 10,000 eggs may be produced.
The eggs will typically hatch in four to seven days. Once the fry emerges, you can feed them special fry foods until they are big enough to eat baby brine shrimp or powdered flake. Shubunkin juveniles are a rather drab black or dark brown color. That provides the fish with a degree of camouflage so that they don’t get eaten by larger predatory fish. The fishes’ true colors appear after a few months when they can be introduced to your main tank or pond.
Shubunkin goldfish are pretty hardy creatures and tend not to succumb to many diseases, as long as their tank is kept clean, and they are fed a nutritious diet. Goldfish diseases are common to most freshwater fish species. The treatment for all these diseases is pretty straightforward and, in most cases, is successful, as long as you identify the fish’s condition promptly.
The most common problem for Shubunkin goldfish is a condition called Ich. Ich is caused by a protozoan parasite that lives in the tank water. Ich usually attacks fish that are weakened by poor water conditions or that are already sick or stressed.
Fish with Ich have a rash of tiny white spots sprinkled across their skin, gills, and fins. Infected fish flick against the substrate and decorations in an attempt to get rid of the parasites.
Flukes and lice
External parasites such as flukes attack goldfish, infesting the animal’s gills and body.
Lice are flattened crustaceans that attach themselves to the body of the goldfish. There are also anchor worms that appear like fine threads emerging from the fish’s body.
Other common diseases
Bacterial and fungal infections can also affect goldfish, and many are fatal if you don’t treat them promptly. Most of these conditions are treatable by dosing the tank water with an over-the-counter antibacterial product, and the fish usually survives if you catch the problem soon enough.
Swim bladder disease
Swim bladder disease is also often associated with constipation and is a common problem with goldfish, especially those with rotund bodies. Affected fish are unable to remain upright in the water and may struggle to swim normally. Often, fish with swim bladder disease remain on the substrate, seemingly unable to swim to the surface.
You can often solve the problem by starving the fish for 24 hours and then feeding live or frozen foods. Also, feeding a cooked, shelled pea can help to relieve the blockage, and the fish will recover quickly.
Shubunkins are usually available in most fish stores, although they can be more expensive than their plainer single-colored cousins. If you can’t find what you want in-store, you may have more luck searching online.
Shubunkin goldfish are hardy, easy to care for, and beautiful to look at. These coldwater fish are perfect for a beginner, and they can be kept in an aquarium or a pond. Every Shubunkin is unique in its colors and markings, so you know that yours is truly one of a kind!
These fish can grow to measure up to six inches in length, and they are very dirty fish. For that reason, you’ll need a large tank fitted with a highly efficient filtration system to accommodate a group of these sociable, community fishes.