Bubble Eye Goldfish: Essential Care and Breeding Guide

Bubble Eye Goldfish are a captivating and unique variety of fancy goldfish known for their distinctive appearance. These small fish are characterized by their upward-pointing eyes, accompanied by two large fluid-filled sacs underneath. Lacking a dorsal fin, these goldfish exhibit a quirky swimming style, adding to their charm and making them a popular choice among fish enthusiasts.

In order to maintain their delicate eye sacs and overall health, Bubble Eye Goldfish require specific care and attention. Their protruding eye sacs can be easily injured or punctured, so it’s essential to provide a safe environment with minimal risk of injury. Additionally, as slow and awkward swimmers, they should be housed with other gentle species, such as telescope goldfish, to ensure they aren’t outcompeted for food and can enjoy a peaceful coexistence.

As omnivores, Bubble Eye Goldfish thrive on a varied diet that includes high-quality sinking pellets, which reduce the risk of air intake during feeding. Supplementing their diet with occasional servings of daphnia, bloodworms, tubifex worms, or brine shrimp can also provide optimal nutrition and promote overall well-being. Understanding and accommodating the unique needs of these fascinating fish will enable aquarium enthusiasts to fully appreciate the enchanting appeal of the Bubble Eye Goldfish.

Bubble Eye Goldfish Origins and History

Selective Breeding in Ancient China

Bubble Eye Goldfish, scientifically known as Carassius auratus, are a unique and fascinating breed of goldfish. The origins of Bubble Eye Goldfish can be traced back to ancient China, where they were selectively bred from wild Prussian carp during the 1700s. These fish are the result of centuries of cross-breeding and genetic mutations that have led to their distinctive appearance.

The selective breeding process that created Bubble Eye Goldfish focused on the development of their most notable traits – the fluid-filled sacs beneath their upward-pointing eyes. These breeders focused specifically on creating goldfish that had larger, fuller sacs, a clean dorsal-less back, and symmetrical eye bubbles.

Popularity in Japan and Beyond

Bubble Eye Goldfish started gaining popularity outside of China in the early 20th century. Their unique appearance captured the attention of people in Japan, where they became highly sought after. Japanese breeders began to adopt and contribute to the breeding techniques, further refining the characteristics of these goldfish.

As Bubble Eye Goldfish gained more attention, their popularity spread beyond Asia to Europe and North America. Today, these goldfish are a beloved variety among aquarium enthusiasts and collectors around the world, with many breeders striving to create the ideal specimen.

Despite their widespread appeal, it’s crucial to remember that Bubble Eye Goldfish require special care and attention due to the delicate nature of their fluid-filled sacs. They should be kept separate from more boisterous fish species to minimize the risk of injury to their eye bubbles and should only be kept with other Bubble Eyes or Telescope Goldfish varieties.

Physical Characteristics

Distinctive Eye Bubbles

The Bubble Eye Goldfish is easily recognizable by its unique and distinctive eye feature. The fluid-filled sacs beneath each eye resemble large bubbles, giving this goldfish variety its name. These sacs are quite delicate and can be easily damaged, so care should be taken when maintaining the fish’s environment. It is best to keep Bubble Eye Goldfish separately from more active or aggressive fish types and away from sharp tank decorations.

Size and Coloration

The average size of a fully-grown Bubble Eye Goldfish is about 5 inches long. They come in a variety of colors, including red, orange, yellow, white, and even black. The color of the bubbles under their eyes should match the rest of their body coloration for a well-balanced appearance.

Fins and Body Shape

Bubble Eye Goldfish have a round and plump body with short, double tails. One unique feature of this fish is that they lack a dorsal fin, resulting in a smooth, dorsal-less back. Unfortunately, the absence of a dorsal fin can lead to some swimming difficulties, making these fish slower and less agile compared to other goldfish varieties.

Housing and Environment

Tank Size and Setup

Bubble Eye Goldfish require a spacious tank due to their delicate eye sacs and slow swimming nature. A minimum of 20 gallons for one fish and an additional 10 gallons for each additional fish is recommended. Make sure that the aquarium has a smooth substrate and decorations with no sharp edges to prevent injuries to the delicate eye sacs. Live or artificial plants can be used, but ensure that they have soft leaves and provide hiding spots for the fish.

Filtering System

A suitable filtration system is essential for Bubble Eye Goldfish. An external canister filter or a sponge filter is preferred since they create minimal water flow, preventing stress on the fish’s bubble sacs. Regular filter maintenance is necessary to keep ammonia and nitrite levels at zero and maintain nitrates at 20ppm or less.

Temperature and Water Conditions

The ideal water conditions for Bubble Eye Goldfish include:

  • Temperature: 65-72°F (18-22°C)
  • pH range: 6.5-7.5
  • General Hardness (dGH): 5-19
  • Carbonate Hardness (dKH): 4-10

Regular water testing and water changes must be done to maintain stable water parameters, ensuring the health and well-being of your Bubble Eye Goldfish. Aim to replace 25-50% of the water weekly to maintain a clean and healthy environment.

Nutrition and Feeding

Bubble Eye Goldfish are omnivores, enjoying a varied diet of plant matter, insects, zooplankton, and small crustaceans. Proper nutrition and feeding habits are essential for maintaining the health of these unique fish.

Diet Recommendations

To satisfy a Bubble Eye Goldfish’s dietary needs, you should provide them with a mix of the following food sources:

  • High-quality sinking pellets: These are preferable over floating flakes, as they help the fish avoid taking in excess air while eating.
  • Frozen or live food: Enrich their diet with daphnia, bloodworms, tubifex worms, or brine shrimp to ensure they get adequate protein and nutrients.
  • Vegetables: Supplement their diet with small pieces of blanched vegetables such as peas or spinach.

Some options for feeding your Bubble Eye Goldfish include:

Food TypeExamples
Sinking PelletsHigh-quality pellets
Live/Frozen FoodsDaphnia, bloodworms, tubifex worms, brine shrimp
VegetablesPeas, spinach (blanched)

Feeding Frequency

Bubble Eye Goldfish should be fed at least 2-3 times per day, offering them small portions to prevent overeating. They have small stomachs and need time to digest their food properly. Overeating can lead to health issues, such as swim bladder disorders or obesity.

It’s important to closely monitor their consumption. Remove any uneaten food after about 5-10 minutes to maintain optimal water quality. Additionally, adjust their feeding routine if you notice changes in their body weight or overall health. This may involve reducing or increasing the frequency of feeding, depending on their specific needs.

Health and Common Issues

Bubble Eye Goldfish are known to be more delicate than many other species of goldfish, and they often face certain common health issues. The following sections outline some of the main concerns one should be aware of in order to ensure their wellbeing.

Bubble Eye Injury

One of the most frequent issues with Bubble Eye Goldfish is eye injuries. These fish possess delicate, fluid-filled sacs that are prone to damage from various sources, such as bumping into objects in the tank, colliding with other fish during feeding times, or even from aggressive or playful tank mates. To help prevent injuries, keep Bubble Eye Goldfish with compatible species and ensure their tank environment has smooth, rounded objects and plenty of open swimming space.

Respiratory Problems

Bubble Eye Goldfish can also experience respiratory issues due to their uniquely shaped eyes and unique body structure. These problems can arise due to poor water quality, bacterial infections, or even stress. To help prevent and mitigate respiratory issues, aim to maintain proper water quality by monitoring ammonia, nitrite, and nitrate levels, performing regular tank maintenance, and providing a stress-free environment for your fish.

Swim Bladder Problems

Swim bladder problems are another health concern for Bubble Eye Goldfish. This condition can make it difficult for them to maintain their buoyancy and might even cause them to swim irregularly or upside down. Possible causes include overfeeding, improper diet, constipation, or bacterial infections. To help prevent and address swim bladder issues, ensure that you:

  • Feed your fish a varied diet, including high-quality pellets or flakes, and vegetables like peas and spinach
  • Avoid overfeeding and provide small, frequent meals
  • Regularly monitor the tank’s water parameters in order to maintain optimal water quality

Remember to always closely observe your Bubble Eye Goldfish and address any signs of health issues promptly. By providing proper care, a suitable environment, and promptly addressing any potential health problems, you can help ensure the health and happiness of your Bubble Eye Goldfish.

Behavior and Compatibility


Bubble Eye Goldfish are known for their gentle and peaceful temperament. They are slow swimmers due to the fluid-filled sacs around their eyes, making them less competitive for food and somewhat vulnerable in a community tank. Their unique appearance and delicate eye sacs require special consideration when setting up their surroundings.

Tank Mates

When selecting tank mates for Bubble Eye Goldfish, bear in mind that they thrive in the company of other Bubble Eye Goldfish. Fast-swimming and aggressive fish species may not be suitable tank mates, as they can potentially damage the delicate eye sacs of the Bubble Eye Goldfish and outcompete them for food. Some suitable tank mates for Bubble Eye Goldfish include:

  • Other Bubble Eye Goldfish
  • Telescope Goldfish
  • Celestial Eye Goldfish

It’s essential to avoid boisterous tank mates and sharp tank decorations to ensure the safety and well-being of your Bubble Eye Goldfish. Regularly monitor the compatibility and interactions between the fish to maintain a peaceful and harmonious aquarium environment.

Breeding Bubble Eye Goldfish

Spawning Process

Bubble Eye Goldfish are eager to breed when the conditions are right. They can be bred in large groups, which reduces the need to distinguish between sexes. On average, a female Bubble Eye Goldfish can lay around 1,000 eggs in each spawning, but only a small percentage gets fertilized and survives to grow.

To initiate the spawning process, you should create a separate tank to raise the fry. This is important because these fish are known to eat their eggs, and having a separate tank prevents this behavior.

Caring for Eggs

Once the eggs have been laid, it is essential to maintain proper water parameters. Bubble Eye Goldfish thrive in water with:

  • Temperature: 65-72°F (18-22°C)
  • General hardness (dGH): 5-19
  • Carbonate hardness (dKH): 4-10
  • pH range: 6.5-7.5

Ensure the appropriate water parameters and monitor ammonia, nitrite, and nitrate levels for healthy fish throughout their development. Perform regular water tests and make necessary changes to maintain these parameters.

Caring for Fry

After the eggs have hatched, caring for Bubble Eye Goldfish fry involves:

  • Providing adequate food: Start by feeding them newly hatched brine shrimp, followed by finely crushed flakes or pellets as they grow.
  • Maintaining clean water: Regularly remove uneaten food and waste to maintain a clean environment.
  • Monitoring water parameters: As with the eggs, proper water parameters must be maintained.

With careful attention to their breeding environment and appropriate care, Bubble Eye Goldfish can thrive and will develop into beautiful, ornamental fish.