Bubble Eye Goldfish; Care Guide, Lifespan, and More

Bubble Eye goldfish are unique-looking fish that can make an unusual addition to any Fancy goldfish collection. These fish are best-suited to life in an aquarium rather than a pond and are probably not the best choice for beginners.

Read this guide to learn more about these strange-looking fish and find out how to care for them.

Origins Of The Bubble Eye Goldfish

It’s thought that every goldfish variety originates from China. Goldfish, scientific name Carassius auratus, were captive-bred from wild Prussian carp during the 1700s.

Modern goldfish do not occur in the wild environment, as all goldfish are captive-bred, although you sometimes see a few unwanted pets that have outgrown their tanks and been released by their owners.

The Bubble Eye goldfish is a unique species of Fancy goldfish, having weird, water-filled bubbles underneath its upturned eyes. Like most round-bodied Fancy goldfish, the Bubble Eye is a very poor swimmer, a problem that’s exacerbated by the fish’s lack of a stabilizing dorsal fin. 

Bubble Eye goldfish are pretty widely available, but they are not recommended as beginner fish or for mixed-species community tanks.

What is a Bubble Eye Goldfish?

The Bubble Eye or Water-Bubble Eye goldfish is one of around 125 different Fancy goldfish varieties, but these creatures are by far the strangest looking of all! 

Bubble Eye goldfish are easily distinguishable from other Fancies by their bubbles. The water-filled bubbles develop when the fish is around six to nine months old, growing to a very large size by the time the animal reaches two years of age. Sometimes, the bubbles grow so big that the fish struggle to see and even swim.

Unfortunately, the unique bubble sacs are very fragile and easily broken. One common injury that affects these goldfish is that the sacs become trapped in the water uptake valves of aquarium filtration systems. So, you’ll need to fit a foam cover to the valve to prevent such accidents.

Broken bubbles heal very slowly and are extremely prone to infection. Most times, the broken bubble regrows but often in a different size and shape to the other bubble, giving the fish a somewhat lopsided appearance. However, sometimes a broken water bubble doesn’t grow back at all. 

To add to the fish’s strange appearance, the Bubble Eye goldfish does not have a dorsal fin on the top of its back. That said, there is one variety of Chinese Bubble Eye that does have a dorsal fin, although that type is not recognized as being of show quality by the Goldfish Society of America (GFSA).

Bubble Eye goldfish are round-bodied Fancy goldfish, having a double tail. The fish’s eyes are upturned rather like those of the Celestial goldfish.

Bubble Eye Goldfish Lifespan

Goldfish can enjoy a long life expectancy of up to 30 years in exceptional cases.

However, Bubble Eye goldfish typically enjoy a lifespan of between ten and 15 years. That said, if you keep your fish in a well-maintained tank and provide them with a correct, high-quality diet, your Bubble Eyes could live to be 20 years old or even more.

What Size Are Bubble Eye Goldfish?

Bubble Eye goldfish are one of the smaller species of Fancy goldfish, generally reaching around 5 inches in length.

It’s crucial to bear that in mind when buying your fish. The specimens you see for sale in your local fish store are juveniles of up to six months old. But that cute little Bubble Eye will grow, doubling in size in just a few weeks. So, make sure that the tank you buy is large enough to accommodate your new pets.

Colors And Patterns

Bubble Eye goldfish are found in a wide range of colors and patterns, including:

  • Blue
  • Red
  • Chocolate
  • Black
  • Calico
  • Red and white bi-color
  • Red and black bi-color

Generally, Bubble Eye goldfishes’ scales are metallic or nacreous.

Price And Availability

Bubble Eye goldfish are typically readily available in good pet stores and online for around $10. 

Is The Bubble Eye Goldfish Suitable For Beginners?

We don’t recommend the Bubble Eye goldfish as a suitable pet for a first-time goldfish owner.

Bubble Eyes are one of the more fragile species of Fancy goldfish, and their strange, water-filled bubbles make them highly vulnerable to injury and infection. Also, the fish’s lack of a dorsal fin makes them clumsy, awkward swimmers that often struggle to compete for food with more agile tank mates.

Bubble Eye Goldfish Care Guide

In this part of our guide, we tell you everything you need to know about caring for these quirky fish.

Tank Size

As previously mentioned, Bubble Eye goldfish can reach around 5 inches in length when fully grown. 

It’s not true to say that goldfish only grow to fit the size of their tank. Fancy goldfish grow rapidly during their first couple of years, so it’s advisable to buy a large tank from the get-go. That saves you from having to upsize the tank in the future. Goldfish will continue to grow regardless; however, growth will be stunted if the tank is too small, and developmental abnormalities are often seen when Fancies are kept in cramped conditions.

For Bubble Eye goldfish, we recommend a tank of at least 10 gallons, increasing by an additional ten gallons per additional fish. Since these goldfish are such appalling swimmers, you need a rectangular tank so that the creatures can easily get to the surface to feed. 

A long, shallow tank also provides more surface area for gaseous exchange, ensuring that your fish have the oxygen they need to thrive.

How Many Fish Can You Keep?

Fancy goldfish species, in general, are sociable, gregarious creatures that do best when kept with others of their kind. However, if you overcrowd the tank, your fish will get stressed, and that can cause disease, injuries, and stunted growth.

The general rule is to allow 1 inch of fish per 1 gallon of water in your aquarium. 

Even though those tiny little baby fish might appear swamped in a 10-gallon or 20-gallon tank at first, rest assured, they will quickly grow to fill it!

Water Parameters

Bubble Eye goldfish need cool water between 65o and 72o Fahrenheit. The water pH level should be in the range of 6.0 to 8.0, with the water hardness between 5 and 19 dGH.

The levels of ammonia and nitrite in the water must always be zero, and nitrates should be 20ppm, or ideally less. 


Goldfish of all varieties are dirty fish that generate a vast amount of waste. Goldfish don’t have a stomach like you do. Everything the fish eat passes straight through the digestive system, where the nutrients are extracted. Waste products are then passed out into the water. In effect, your goldfish is a swimming garbage disposal system! For that reason, a highly efficient filtration unit is essential in a goldfish tank.

The filtration system you choose must circulate the water through the mechanical and biological filter media at least four times every hour, 24/7/365, to keep the water clean and safe for your fish.

Bubble Eye goldfish are poor swimmers that can’t cope with a rapid flow through the environment, which is a problem when you’re running a powerful filtration unit. To mitigate that, choose a filter with an adjustable outflow valve or buffer the current with dense planting or decorations.

Tank Maintenance

To ensure that your filtration system functions efficiently and your aquarium remains clean and healthy for the Bubble Eyes, you’ll need to carry out a few routine maintenance tasks.

Every week, you must perform partial water changes of up to 30% to remove nitrates from the water and ease the load on your filter media. Any deposits of organic waste, plant debris, and uneaten fish food must be removed with an aquarium vacuum cleaner. Problem hotspots to focus on include underneath internal filter boxes, around plant bases, and under ornaments.

If you keep living plants in your setup, you’ll need to snip away brown leaves and broken stems. Use an algae scraper to keep the glass clear so that you can enjoy an unobstructed view of your fish, but leave a few small colonies of algae somewhere out of sight; your fish will enjoy grazing on the algae between feeding times.

Tank Decoration

You can choose whatever aquarium décor scheme you fancy for your goldfish tank. However, you should remember that Bubble Eye goldfish are delicate creatures that are prone to injury.

Stay Safe!

Bubble Eye goldfish are lousy swimmers with very poor eyesight. So, ensure that your tank doesn’t contain anything sharp that could injure the fish. By all means, have smooth decorations, such as stones, glass pebbles, driftwood, and the like, but leave the central area of the water column free from obstructions so that the fish have plenty of open water swimming space.

Large gauge, smooth gravel makes a good substrate for the goldfish, as they spend much of the time rooting around the bottom of the tank scavenging for scraps.


Living plants make an excellent addition to any fish tank. Plants remove harmful nitrates from the water to use as fertilizer, as well as taking up carbon dioxide and giving off oxygen through photosynthesis.

Unfortunately, goldfish of all varieties are partial to nibbling on young shoots and tend to uproot fragile plant species while foraging for scraps. However, there are a few tougher plants you can include in a goldfish tank relatively safely, such as Marimo Moss Balls, Java Fern, and Anubias


Aquarium lighting is primarily used for the benefit of living plants and so that you can enjoy a good view of your fish.

That said, goldfish do better when provided with a day/night experience that you can replicate by using aquarium lights. If goldfish don’t have those clear day/night periods, they can become stressed, and that can cause health issues in the long term. 

Set the lights to come on in the morning, telling the fish that it’s time to get active and feed, and have the lights go out at night so that the fish know it’s time to rest. If possible, choose a lighting unit that has an integral automatic timer. Alternatively, most good DIY stores stock inexpensive timer plugs that work just as well.

Nutrition and Feeding

Goldfish are very easy to cater to, eating a mixture of algae, plant matter, and meaty foods. A good basic diet for your Bubble Eyes should include:

  • High-quality goldfish flakes and pellets
  • Frozen meaty foods
  • Blanched fresh veggies (zucchini, lettuce, peas, etc.)

The inclusion of a portion of meaty protein in your Bubble Eyes’ daily diet is crucial for the fishes’ digestive health. 

All round-bodied varieties of goldfish are susceptible to gastric problems, such as bloating and constipation. When goldfish are fed too much dry food, constipation often occurs. That accumulation of food compromises the fish’s swim bladder, causing the fish to struggle to remain on an even keel. Luckily, the problem is usually easily remedied by offering the affected Bubble Eye a portion of meaty food or fresh veggies.

What About Live Foods?

Although your Bubble Eye goldfish would love to have a portion of live food as a treat, we recommend that you avoid introducing live foods to your tank. Often, live food comes with parasites and bacteria that could harm or even kill your fish. So, unless you fancy keeping home a brine shrimp hatchery, stick to feeding your goldfish frozen meaty foods instead.

How Much To Feed?

Goldfish should receive two or three small meals daily. Feed your Bubble Eye goldfish only what they will eat in a few minutes to prevent overfeeding.

What Are Good Tank Mates For Bubble Eye Goldfish?

Goldfish are sociable, peaceful creatures that thrive when kept in groups. 

When it comes to choosing tank mates for Bubble Eye goldfish, it’s best to keep conspecifics or other types of egg-shaped Fancies, such as Telescope Eye goldfish and Celestial goldfish Lionheads and the like. 

Although shrimp and snails make interesting additions to a Fancy goldfish community tank, they are vulnerable to being eaten, so choose only large species that are too big to fit into the fishes’ mouths. Fish species to avoid include fast-swimming, slim-bodied goldfish varieties that could outcompete the Bubble Eyes at feeding times or bump and barge them, causing injuries. Fin nippers should also be avoided, as they might hassle and stress the Bubble Eyes.

Health and Diseases

Bubble Eye goldfish are somewhat more delicate than many other species of goldfish, and there are several common health issues that can affect them.

Eye Injuries

Bubble Eye goldfish are very prone to suffering eye injuries that are usually caused by the fish bumping into objects in the tank or colliding with other fish during a feeding frenzy. 

If you have to net your fish, do so very gently, as the water-filled bubbles are easily ruptured and torn.

White Spot Disease

White Spot Disease is also commonly called Ich or Ick.

Ich is caused by the Ichthyophthirius multifiliis parasite that lives in most freshwater and marine tanks. The parasite only attacks fish that are already weakened by stress or disease, burrowing into the fish’s skin during the early stages of its lifecycle. Infected fish flash or rub against solid objects in the aquarium to try to remove the parasites, and within a few days, a sprinkling of tiny white dots appears across the fish’s body, fins, and gill covers. 

You can treat Ich with an over-the-counter medication that you can buy from good pet stores.

Bacterial Infections

Fish that are stressed, injured, or diseased are vulnerable to secondary bacterial infections. The symptoms of infection can include: 

  • Red patches on the skin
  • Bleeding ulcers
  • Inactivity
  • Ragged, torn fins
  • Missing scales
  • Poor appetite
  • Labored breathing

Many minor bacterial infections are treatable with a proprietary medicine that you can buy in pet stores.


Fluke is the generic term that’s used to refer to external parasites that can attack goldfish, including:

  • Anchor worms
  • Fish lice
  • Skin flukes

Flukes are often accidentally carried into your tank on new fish, live food, or living plants. 

The easiest way to keep flukes out of your aquarium is to quarantine any new fish in a separate tank for at least two weeks before adding them to your main setup. Inspect plants carefully and remove anything suspicious from underneath the plant leaves. To be ultra-careful, rinse plants in a solution of tank water and an antiparasitic medication.

Breeding Bubble Eye Goldfish

Bubble Eye goldfish are relatively easy to breed if provided with a high-quality, varied diet and given the correct aquarium conditions.

You’ll need a mix of male and female Bubble Eyes to start your breeding project. Unfortunately, the sexes are pretty much impossible to differentiate in juvenile goldfish. However, once the fish reach maturity, females are typically plumper and slightly larger than males. When in breeding condition, male goldfish develop small white prickles or tubercles on their head and gill covers.

Usually, if you start with a group of five or six individual fish, you should get a mixture of both sexes.

Spawning Conditions

All goldfish varieties, including Bubble Eyes, are egg layers. Like their wild carp relatives, goldfish begin spawning when the water warms up at the end of spring.

For spawning to take place, the fish must be in prime condition and free from disease and injury. Set up a heavily planted 20-gallon tank, and add a few large, flat rocks or spawning mops where the fish can deposit their eggs.

Keep the male and female Bubble Eyes separate for a few weeks before introducing them to your spawning tank, as that can help to increase the fishes’ interest in breeding. Increase the water temperature by 3o every day until the tank temperature is between 68o and 74o Fahrenheit.

Change 20% of the tank water every day until the fish begin spawning, and offer the Bubble Eyes generous portions of protein-rich, high-quality foods, such as bloodworms and brine shrimp every day.


The male Bubble Eye goldfish chases the female all around the tank, pushing against her body to stimulate egg-laying. As the female deposits her eggs, the male fertilizes them. That process can last for several hours, and around 10,000 eggs can be laid in just one spawn!  

Goldfish are terrible parents, gobbling up the eggs before they have a chance to hatch. So, you’ll need to move the adult fish to your main tank once the eggs are laid. 

After around seven days, the eggs should hatch. Goldfish fry is free-swimming as soon as they hatch, and you can feed them commercially prepared fry food until the fish are able to cope with finely crushed goldfish flakes and live baby brine shrimp.

The baby fish grow quickly, and once they’re an inch or so in length, you can safely add them to the main tank with their parents. Note that all juvenile goldfish are brown or bronze for the first few months to protect them from predators. Within a couple of months, the Bubble Eyes will start to show their true adult colors.

Final Thoughts

Did you enjoy our guide to the weird and wonderful Bubble Eye goldfish? If you did, please take a moment to share it!

Bubble Eye goldfish are sensitive, fragile creatures that are not the best choice for beginners to the goldfish keeping hobby. However, if you have experience keeping Fancy goldfish, you might want to take on the challenge of breeding these beautiful, exotic creatures. You’ll need a large tank of at least 10 gallons with a powerful filtration system to keep these fish happy and healthy, and you must have the time to devote to maintaining the environment for the fish.

Do you keep Bubble Eye goldfish? Tell us your story in the comments box below.

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