Bubble Eye Goldfish: Care, Diet, Lifespan, Tank size and more

Bubble Eye Goldfish Full Care Guide

The Bubble Eye goldfish is one of the most distinctive freshwater fish because of its very unique physical features. This is why they have become so popular in the aquarium hobby space. 

However, what is not so popular is the information needed in order to satisfy their special requirements. 

They need special care which can only be exercised with the right information and experience. 

In this guide we talk about about everything you need to know to take care of them successfully from tank size, tank requirements, water parameters, food and diet, breeding, tank mates and much more.

Bubble Eye Goldfish is one of the most unique members of more than 120 captive-bred goldfish varieties. This particular species has a very unique associating feature, a bubble sac on both sides of their eyes.


These bubbles are one of the most beloved features of the fish leading to its addition into many aquariums.


Since they are exclusive captive-bred variety, they can only be found in aquariums in different part of the world. They can not be seen swimming in the wild anywhere in the world. 

Carassius Auratus diving towards the bottom of a tank

By Angie Torres CC BY-SA 2.0, Wikimedia Commons

What I like about the Bubble Eye Goldfish

  • How their bubbles sac jingles as they swim around the aquarium
  • Their peaceful nature even when combined with other tank mates (ideal mates obviously)
  • How they differ from most freshwater fish in terms of t body nature, particularly their lacks of dorsal fin.
  • How they swim in a slowly adorable manner


It’s always beneficial to understand the origin of any aquarium fish species as it helps a lot when caring for them. Generally, aquarium fish do better when their habitats conditions are imitated in the tank.


Even though the Bubble Eye Goldfish are exclusive captive-bred it’s still useful if we can understand where their ancestors originated from. 


Goldfish were initially developed in China. In the 1500’s they were traded to Japan and later arrived in Europe and America in 1600’s and 1800’s respectively. 


Much of the fancy goldfish we see today were bred by Asian breeders.


They had engaged in goldfish cross-breeding centuries ago. This is what resulted in the various colors and shapes of different goldfish existing now. 


Domesticated goldfish are now available across the globe.


The goldfish of today are ancestors of a species of wild carp known as the Prussian Carp, Silver Prussian Carp or Gibel Carp Carassius gibelio (syn: Carassius auratus gibelio), which was illustrated by Bloch in 1782.


The wild carp originated in Central Asia Siberia. They occupied the slow-moving and stagnant water of lakes, ponds and rivers of that area. 


The wild carp feed on plants, detritus from bark, leaves, branches and small organisms such as insects and crustaceans in their habitat.


 The Bubble Eye Goldfish with scientific name (carassius auratus auratus) is what is known as the Water-Bubble Eye Goldfish.

Bubble eye goldfish Care Snippet

  • Size of fish: 3-4 inhes normally with 5.0 inches being the maximum
  • Minimum tank size: 10 gallons (38L)
  • Aquarist Experience Level: Medium
  • Temperament: Gentle
  • Temperature: 65-72°F (18.3-22.2°C)
  • pH: 6.0-8.0
  • Hardness: 5-19 dGH
  • Common Diseases: Ich, Dropsy
  • Ideal aquarium: Celestial goldfish, Telescope goldfish

Bubble Eye Goldfish Appearance

As the name suggests the Bubble Eye Goldfish has bubble sacs beneath their eyes as the most distinguishing physical feature. 


Many people think that those bubbles are only filled with air but that is not the case. They are filled with fluids thereby making them jingle as the fish swims.


The size of the bubbles is not the same for all the fish, they differ from specimen to specimen.


Some specimen have moderate size while others have theirs so big that it causes them to have difficulty in swimming. The sacs generally affect their vision, especially when they become very big. 


Their bulbous sac coupled with the direction of their eyes makes it difficult for the Bubble Eye Goldfish to see where they are going.


As the bubbles become bigger, they push the eye direction more upward.


When dealing with the Bubble Eye Goldfish one has to be careful. Those sacs are as delicate as they look. They can easily get popped if care is not taken. 


Although in most cases their popped sac regenerate on its own, they don’t usually return to the same form and size. This can give rise to an unbalanced looking fish.


The second most distinguishing feature of the Bubble Eye Goldfish is their lack of dorsal fin. Their backs are empty, unfortunately, this lack of dorsal fin can lead to some swimming difficulty. 


A bubble Eye Goldfish exploring somewhere around middle layer of a tank

By Jordan Hartig CC BY-SA 3.0, Wikimedia Commons

The fish has a double tail fin that splits creating four points. Conveniently enough, their tail fin is long and helps provide some balance while they swim. This somehow makes up for the absence of the dorsal fin.


Their body shape is rounded similar to an egg but surprisingly, that does not impede their movement. 


Their body shape and size is similar to that of the celestial goldfish. 


They also have some pectoral and anal fins.

As for their color, the Bubble Eye Goldfish comes in different colors that include solid blue, red, gold, brown or white. 


You can also find some with multiple colors. A combination of red and white spots, red and black spots and even some with bevy of colors that create a calico pattern can be seen.


Identifying the sex of these fish is a bit tricky due to the lack of many features that differentiate the genders. 


In fact, it is impossible to sex a young Bubble Eye Goldfish. It’s only when they become full adults that you can see some differences.


Generally, females take on a plumper shape while the males develop tiny tubercles on their heads and are a bit slender than the females. 


The bubble eye goldfish can grow up to a maximum size of 5.0 inches (12.70cm) long in home aquariums. 


While they sometimes grow even bigger in very large tanks they rarely do so in home aquariums.

Bubble Eye Goldfish Care

It is not recommended for beginners to keep a Bubble Eye Goldfish. It is also not recommended for community aquariums.


The reason is that they are among the most delicate species of goldfish. They have a low tolerance for pollution and need a lot of breathing space.


Not to mention, their delicate sacs can get popped by many fish.


Another thing is, they are slow eaters, thus, will not thrive if combined with very active and competitive tank mates.

These fish are easily affected by rushing waves of water. So, it’s essential to be careful with the filter uptake valves. Strong water flow can push them and their bubble sacs can get sucked into the valve and burst. 


Putting some soft sponge filter media over the valve helps a lot.


Because of their care demands it not ideal to keep them in a small bowl without provision for heater and filtration mechanism like some people do. 


Instead make sure you provide them with a decent aquarium with proper filtration setup, especially a biological filtration.

Tank size and requirements

A minimum of 10-gallon tank is recommended for a Bubble Eye Goldfish.

This is because they require a lot of space to make sure their tank is not easily contaminated.

It is more suitable to start with a 20-gallon tank for your first goldfish. After that, if you plan on adding more, you can then allocate that 10 gallons of space per every fish you add. 

The benefit of allocating that amount of space is that a large amount of water per fish generally help dilute the amount of waste in the tank and lowers the number of water changes needed. 

Additionally, they take in a lot of oxygen so if you cramp them without enough space allocation, they will most likely struggle with their breathing.


Besides, Bubble Eye Goldfish experience stunted growth and become more prone to diseases when their tank is not adequately spacious.

Tank shape is also an important element to look at, as surface area determines the shape of the tank. A tank that provides more surface area is more ideal.


For instance, a tank that is way longer than its height provides more surface area and more oxygen than a tall tank. Therefore, elongated tanks are more desirable than a tall or oval tank. 


It’s recommended to use medium-sized gravel at the bottom of their tank as the substrate, but make sure the gravel is smooth.


In the course of their food scavenging, they often swim down the bottom of the tank in search for food. So it helps if the gravels and plants down there are very smooth.


There have been some cases in which their bubble sacs get popped up by sharp elements in those kind of areas.


You can easily decorate the tank with smooth gravels, and smooth natural or artificial plants. 


For the natural plants you can go for plants such as Java Moss, Java fern or Anacharis. Not only do these plants help oxygenate tank more they are easy to care for as well.


The only downside to using natural plants is that Bubble Eye Goldfish are known for eating and uprooting plants.


In case of the artificial plants, it is recommended you go for silk faux plants instead of plastic ones. The thing is they are less smother and can sometimes come with rough surfaces.


Another aspect of the tank requirement is filtration. 


The most recommended filtration system for the Bubble Eye Goldfish is an under-gravel system. 


Regardless, if for some reason you are not using this, make sure you outfit your filtration system filter valves with a soft valve to prevent injury to the fish.


Lastly, lighting is another aspect we need to talk about. It’s not a subject that is concerned with greatly. Yet, lighting can to some point aid the fish when navigating due to their poor eyesight 

Water parameters

Bubble Eye Goldfish need a well maintained and healthy tank with the ideal water chemistry. It is essential to maintain the water properly by making water changes frequently.


Consequently, routine weekly changes of 1/4 to 1/3 is recommended. 


Algae is one of the major tank contaminants. You can lower that by introducing snails into the aquarium. 


Conversely, you can introduce algae eating fish species that are compatible with the Goldfish.


Bubble Eye Goldfish do best if kept at a temperature of between 65°-72°F (18°-22C°). Be careful, they don’t tolerate abrupt temperature changes. And unlike other goldfish, they also cannot tolerate temperatures much lower than 60°F(16°C). 


The question; Does a Bubble Eye Goldfish need as a heater? Will depend totally on the location of your tank. 


If you have the tank in a room where the temperature goes below 60°F (16°C) then you will most likely need a heater for their aquarium.


On the other hand, if your room temperature fluctuates between 18°-22C° then having a heater might not be necessary for you

Bubble Eye Goldfish Tank Mates

The Bubble Eye Goldfish are very social and nice scavengers as long they are together with their ideal mates. It’s essential when choosing their mates to consider their deformities.


They are visually handicapped. Secondly, they are not fast swimmers due to the absence of stabilizing dorsal fin making it difficult for them to compete for food. 


Lastly, their bubble sac could easily get popped by other species that are either aggressive or playful.


When picking for their companions, you have to consider species they share similar physical traits with. That is species that are also handicapped and passive.


Below are some of the ideal tank mates of the Bubble Eye Goldfish.

GroupCarassius Auratus swimming in a tank

By deror-avi CC BY-SA 3.0, Wikimedia Commons

Celestial goldfish– The Celestial Goldfish also called the Celestial Eye Goldfish is an egg-shaped variety of goldfish. This fish normally reaches 5’’ (13cm) in length, in some cases can reach up to 6’’ (15cm).

Their body is short and stubby with double tail fin and a double anal fin. It lacks dorsal fin and its eyes are positioned upward, so in many ways, it is similar to the Bubble Eye Goldfish.

Telescope goldfish– The Telescope Goldfish is another variety of goldfish. They also have a rounded or egg-shaped body. Their body is short and stubby with a very wide head and another split tail fin that is convenient in length and a bit forked.


They have protruding eyes. Today they are available with long flowing fins and a couple of other tail fin styles such as the butterfly tail and broad tail.

Lionhead Goldfish– Lionhead Goldfish is the most popular and well known of the dorsal-less goldfish. It has a very rounded or egg-shaped body unlike the shubunkins and the common goldfish which all have a very long slender body.


Its shape is quite similar to that of the Bubble Eye Goldfish. In some cases, this fish broad head (apart from its nostrils and mouth) becomes completely covered with fleshy growth which can sometimes impede their vision. 

Black moors– the Black Moors are another fancy goldfish that have a rounded or egg-shaped body. It’s shape is enhanced by its large bubbles like eyes, protruding from the side of its head and its long flowing finnage. 


Its distinctive dark color and bulging eyes have given rise to its many names such as “Black Peony Goldfish” and “Dragon Eye Goldfish. 


Young Black Moors have flat eyes, it’s as they mature that the eyes start to bulge.

Common diseases

To lessen the chances of your Bubble Eye Goldfish getting sick, you have to provide and maintain their ideal aquarium conditions. Next you need to  feed them good food and make sure their environment is not filled with waste.


Whenever your fish becomes ill you must treat them in a timely manner. In many cases they make full recovery if that is adhered to. 


Untreated diseases in most times can lead to death and may also get transmitted to other unaffected fish.

When treating an individual fish its better to quarantine the affected fish to a separate tank. Preferably a tank with no plants, gravel base and also, its important to perform regular partial water changes. 


In a case where the diseases appear to have affected the entire tank it may be best to treat the entire tank. You can do that by following the doctors or medications instructions. 


Bear in mind that some medications can negatively affect the chemical balance of the water, like by destroying the beneficial bacteria in the tank.


Mainly, Bubble Eye Goldfish diseases are mostly the ones that afflict other freshwater fish therefore their causes, symptoms and treatments are also similar.


The common diseases include fungal infection, bacterial infection protozoa and parasites. 


Then there are diseases caused by injuries such as the infection that develops when the fish bubble sac is popped.

Ich- An ich caused by a protozoan is one of the common diseases that affect these fish. This disease is very easy to identify as the fish body appear as if it’s sprinkled with salt. 


Luckily it can easily be treated if measures are taken in time, otherwise it can become fatal. 

Costia– Costia is caused by a parasite, a microscopic protozoan flagellate that normally attacks goldfish with a lowered immune system. The parasite attaches itself to the skin and gill membrane digging into their top epidermal cells and consuming their content.

Costia can kill very fast if not treated quickly because it can do major damage if it attaches itself to the fish gills.

 One of the major symptoms of Costia is a cloudiness of skin.

Flukes- These are flatworms about 1mm long with hooks around their mouse. The parasite flukes can affect both the body and gills of a goldfish.

If not treated quickly they can kill a fish by destroying its gills and then move on to the next fish in the tank. When in gills of the fish they lay eggs in the darkness of the gills.

Symptoms of flukes include redness of the skin, sunken bellies and mucus on the body or gills.

Swim bladder- Swim bladder disease is a condition experienced by goldfish when their swim bladder fails to function normally. It can happen as result of diseases, other physical abnormalities, environmental factors, poor nutrition, or other reasons that can not be diagnosed.


Swim bladder leads to the inability of the affected fish to maintain buoyancy thus having difficulty in controlling their ability to float.

Dropsy- This is as a result of bacterial infection caused by a bacteria called Aeromonas. 

The symptoms of dropsy involve swelling of the belly or in some cases the whole of the body. Apart from the swelling, fish’s scales may begin to protrude from its body almost to the point where it looks like they might pop off.

Other ailments include constipation indicated by loss of appetite and swelling of the body.  These are mostly caused by inappropriate diet. 

Another thing to watch out for is wound, those can get easily infected thereby creating ulcers.

Wounds can also get infected by bacteria and fungus. Like any other ailment they should be quickly treated when they develop. 

Bubble Eye Goldfish Food and diet

There is no much headache when it comes to feeding the Bubble Eye Goldfish. They are omnivorous and eats almost anything. Like other goldfish, flakes is one of their most common food.


It is recommended you feed them sinking flakes instead of floating ones because they are known to take in a lot of air when they eat. 


Other food you can provide them with include brine shrimp, tubifex worms and bloodworms. You can also drop some vegetables and fruits in the tank, they naturally like to hunt for food at the bottom of the tank.


The Bubble Eye Goldfish are slow eaters. That’s why it helps to not combine them with aggressive eaters as they can’t instantly gobble food up like many other fish.

Temperament and general behaviour

Bubble Eye Goldfish are among the most peaceful fish species out there. They get along great with their ideal mates. 


They swim slowly thanks to their egg-shaped body and absence of dorsal fin to explore their habitat through plants and other appealing features.

A Bubble Eye Goldfish swimming across a tank

By Lerdsuwa CC BY-SA 4.0, Wikimedia Commons

Bubble Eye Goldfish Breeding

The female Bubble Eye Goldfish becomes fatter during breeding due to being ripe with eggs. That’s more noticeable when they are viewed from above. 

As for males, they develop white pricles also called breeding tubercles during this season. 

These goldfish are egg layers and spawn easily when their tank conditions are ideal. It’s important to note that goldfish naturally spawn only during sprint time in their natural environment.

Ideally, mimic the conditions of their habitat in your aquarium and keep them in large groups. That will encourage them to spawn more. Keep in mind they can be bred in groups as small as five specimens. 

To achieve that, provide a minimum 20-gallon aquarium and try to create a lush environment with lots of vegetations. Plants are important as they provide areas which help support the eggs.

Few factors help induce their spawning, one being the temperature. 

To induce the spawning, the temperature of the tank should be gradually dropped to around 60°F(11°C). It should be slowly dropped at the rate of 3°F(2°C) per day until they start spawning. 

Their spawning normally starts when the temperature is between 68° F and 74°F (20°-23°C). 

The next important factor regarding the spawning is feeding. It’s recommended you feed them high protein food like worms, brine shrimp at this time.

Feed them reasonable amounts 3 times a day and make sure they are not overfed. Otherwise leftovers will sink to the bottom of the tank and contaminate the water. 

It is also recommended you maintain their breeding tank with partial water changes of about 20% per day. 

Before spawning starts just as the water temperature increases, the male will start chasing the female in a non-aggressive manner. The chasing can go on for several days and also, the fish color intensifies during this time. 

During the spawning, the female usually twirl from side to side and the male will push her against plants. This action will stimulate the female to drop her tiny eggs which the male then fertilizes.

The eggs then stick to plants or a breeding mop. This spawning process can last for 2 or three hours and can result in up to 10,000 eggs.


Removing the parents from the tank after the spawning is complete to a separate tank is recommended. 


Bubble Eye Goldfish have a habit of eating as many eggs as they can find. 


The fertilized eggs take between 4 to 7 days to hatch depending on the temperature. 


You can feed the fry foods such as infusoria until they become matured enough to eat things like brine shrimp, flakes or the same type of food the parents eat. As long as the food is crushed into smaller easy consumable particles they will no problem taking it. 


You will notice that the babies are dark brown or black. These colors help conceal them from the parents so they don’t get eaten by them. 


The babies also will also not have the bubble sac. Those will start to develop at around 6 months of age. 


I hope that after going through this guide you have fully realized what it would take to keep a Bubble Eye Goldfish successfully in your aquarium. 


I also hope that you give them a short as long as you are committed to adhering to all the requirements.


With all its special needs, the Bubble Eye Goldfish is truly one of the most delightfully looking fish you can have in your aquarium. 


When you keep them you get to reap the benefit of watching them move in a very adorable manner. I know I rather watch that than turn on the TV most of the times, Haha.

Please feel free to rich out if you have any question we haven’t covered or if you have any info you think will help improve this guide. We’ll be more than happy if you do.

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