Telescope Goldfish: Ultimate Guide (Care, Diet, Breeding & More)

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Written By Matt Stevens

Hi, I'm Matt! I've been obsessed with fishkeeping for over 15 years now and created this site to share my knowledge with others.

Telescope Goldfish are an exceptional Goldfish variety with two protruding eyes and an iconic egg-shaped body. If you love the spectacular beauty of the Fancy Goldfish varieties, these fish might be the perfect addition to your aquarium.

The real question is, how much are you familiar with Telescope Goldfish’s care requirements in captivity?

This guide has all the vital information you’ve been looking for to keep healthy Telescope Goldfish at home. It will cover the fish’s care guidelines and other interesting facts such as general appearance, tank size, behavior, diet, tank mates, breeding, and more.

Species Overview

For a long time, it’s been clear that the Goldfish varieties are descendants of a specific wild carp community called the Prussian Carp. Telescope Goldfish is no exception. Like their ancestors, Telescope Goldfish might have originated from the slow-moving Asian ponds, rivers, and lakes.

Specifically, Telescope Goldfish, also known as Dragon Eye Goldfish, Globe Eye Goldfish, or Demekins, were first developed in China in the 1700s. But today, they’ve become a mainstay in the aquarium community, quickly rising in popularity to become one of the most sought-after Goldfish varieties.

Scientifically, Telescope Goldfish are called the Carassius auratus and can be kept in home aquariums as a single fish or in small groups.

Even though they are not ranked among the most endangered species, Goggle Eyed Goldfish have no wild populations these days. Most of the species are captive-bred around the world, thanks to their simplified breeding process.

Lifespan10-15 Years
Care LevelModerate
Behavior & TemperamentPeaceful
CompatibilityPeaceful fish community
Food and DietOmnivores
SizeUp to 5 Inches
Tank SetupFreshwater with artificial plants
Tank Size (Minimum)10 Gallons


Telescope Goldfish have an average lifespan of 10-15 years. However, they are known to surpass this to reach up to 20 years in a properly maintained habitat.


Telescope Goldfish are goldfish with big eyes. They are famous for their iconic telescopic eyes, which have elicited mixed reactions within the fishkeeping community.

While some aquarists see their protruding eyes as the epitome of true beauty, others can’t keep up with their quirky look and may prefer other Goldfish varieties such as Black Moors to Demekins.

Regardless of where you belong, Goggle Eye Goldfish will be a unique addition to your tank, with a beautiful, egg-shaped body only seen in the Fantail Goldfish. These fish have short bodies with large heads and well split caudal fins.

Telescope Goldfish’s large eyes are the most distinctive feature of all, and you will see them perfectly positioned inside the telescopic stalks as if to protrude from the head.

Aside from that, Big Eyed Goldfish have long, free-flowing fins, with some species showing unique tail variations in the form of the veil, butterfly, and broadtail shapes.

In terms of color variations, Telescope Goldfish can have nacreous or metallic scales. The general body coloration will be white, chocolate, blue, or red. In addition, you can find the Telescope varieties of tri-colored and calico forms as well as the bi-colored fish with red and white or black and white coloration.

Conversely, Panda Telescope Goldfish is a popular Telescope variety with an exclusive black and white coloration. If a Telescope Goldfish were to assume a completely black coloration, it would be called Black Moor Goldfish, which is a popular Goldfish variety.


Generally speaking, Big Eye Goldfish will only reach a maximum of 5 inches in captivity. But they can grow up to 8 inches with the best environmental conditions.

Telescope Goldfish Care

First thing first, Telescope Goldfish are not as beginner-friendly as many Goldfish varieties may be. Usually, this is attributed to its delicate telescopic eyes that may require more attention compared to many other species.

As the head growth extends, they may cover the fish’s face, reducing its vision dramatically while exposing it to all manner of physical injuries and infections.

The rest of the aquarium conditions can be flexible, starting with the water quality. Unlike many species, Telescope Goldfish will thrive in the right community tank or a backyard pond as long as it’s a safe and well-maintained environment.

Be careful with the fish’s dietary needs because the Pop Eyed Goldfish can’t match the competitiveness of agile species when it comes to feeding.

Also, investing in a water heater may not be necessary if you keep Telescope Goldfish at home, but having the right filtration equipment is crucial to maintaining the best possible water conditions.

Find out more about the fish’s general care in the next paragraphs;

Tank Size

Your Telescope Goldfish will thrive in a minimum tank size of 10 gallons in captivity. But, this is only a reasonable size if you keep a single fish in captivity.

We recommend anything between 20-30 gallons for a start. Then, you should factor in an extra 10 gallons to accommodate every new species you will introduce to the same habitat.

Water Parameters

As far as the tank water parameters go, Big Eye Goldfish can withstand slight changes for a short period.

But if its rapid temperature drop, your fish may never survive the sudden changes in water conditions. So, here’s the summary of what an ideal environment for Big Eyed Goldfish should entail;

  • Water Temperature: 65°F-72°F
  • Water Hardness: 5-19 dGH
  • pH Levels: 6.0-8.0

What to Put in Their Tank?

To begin with, Telescope Goldfish need enough oxygen to remain healthy and active in captivity. And, this means you must invest in the right air filter or pump to maintain stable conditions.

Also, good filtration will be key to lowering the ammonia and nitrate levels inside the tank to give your fish an almost perfect environment for survival.

Filtration alone improves the water quality, and the faster you remove leftover foods and waste materials, the easier it will be to keep a healthy Pop Eyed Goldfish community.

Next, you should use a gravel substrate to create the best environment for a thriving Telescope population.

You will have flexible options with the tank décor, but never forget the elephant in the room, Telescope Goldfish’s delicate eyes.

With that in mind, you will want to use everything sparingly while avoiding any sharp objects and rough surfaces that could inflict bodily harm on your little Telescope Goldfish.

For the same reason, you should use driftwood and smooth rocks cautiously or avoid them altogether when introducing the tank elements.

Live plants are the most suitable options for most Goldfish varieties, but we can’t say the same for Bugeye Goldfish. These species are fond of digging live plants and may suffer from self-induced injuries from natural vegetation.

Instead, you can introduce the right artificial plants that are safe for your pet buddies. Even at this point, silk plants will be the most suitable option in place of the pointed, plastic types.

Lighting should never worry you because the natural aquarium light is just enough to keep your Big Eye Goldfish active.

Common Diseases

If you keep them in a well-maintained habitat with suitable tank water conditions, most of Telescope Goldfish diseases are easily avoidable.

Still, these fish are susceptible to many diseases commonly seen in the freshwater fish community. By this, we are talking about Ich, swim bladder, dropsy, bacterial infections, and external parasites.

Ich should be easy to identify because it will turn the fish’s body into a rough surface, with multiple visible spots spread all over. It can be lethal without early intervention, but you can manage it with the right medications.

On the other hand, dropsy is a bacterial infection with a fatal outcome if you don’t act swiftly. So, you may need to seek an expert’s advice or get the right antibiotics right away.

Finally, the earliest indicators of swim bladder disease will be an unusual swimming pattern and trouble balancing the fish’s bodies in the water. This condition is associated with several factors, including constipation, parasitic infection, physical deformity, and poor nutrition.

Aside from over-the-counter medicines, a few natural remedies such as feeding your fish on frozen peas can help relieve the symptoms of swim bladder disease. 

Sometimes, poor water quality is to blame for endless diseases within a Goldfish community. And when managing any disease within the aquarium community, it’s necessary to isolate the infected fish and readjust the tank water conditions as fast as possible.

Also, be keen to avoid the adverse effects of popular medications. It’s helpful to read and understand the instructions before using any medication on your diseased Goldfish community.

What Do Telescope Goldfish Eat?

As the true omnivores, Telescope Goldfish will eat any food that suits their daily routine. Be it flake, frozen, or live foods, these fish won’t be picky when it comes to feeding.

But to maintain a balanced diet at all times, ensure your fish get top-quality flake food in addition to protein-rich sources such as bloodworms, brine shrimps, tubifex worms, or daphnia.

Demekin Goldfish may take longer than usual to complete a regular meal. So, be sure to give them enough time to feed while limiting the possibility of overfeeding.

Behavior & Temperament

Telescope Goldfish are social fish and best companions to many freshwater fish species. They are peaceful in a community aquarium and lovely as the only fish or together with the right tank mates.

Because of their scavenging abilities, it would be unwise to introduce fellow scavengers or other bottom-dwelling species in the same space.

With their peaceful temperament, Telescope Goldfish will never scramble for food with the more active and fast-moving species. So, that should be a key point when introducing new buddies to the same habitat.

Telescope Goldfish Tank Mates

Generally, Telescope Goldfish can thrive in a community aquarium with the right tank mates. And in many cases, the most suitable companions are equally handicapped fish that are either slow-moving in captivity or with poor vision.

This group includes similar Goldfish varieties as listed below;

Aside from the mentioned tank mates, Telescope Goldfish also do well with fellow species, where they will live peacefully without competing for food and other resources.


Telescope Goldfish are easy to breed under the right conditions. The female species are egg layers, and their social nature simplifies the spawning process in captivity. These fish will easily pair up if kept in small groups.

The breeding season usually happens in spring, so you will want to recreate similar conditions in captivity. At this point, the regular tank won’t be enough to encourage the breeding process. The adult fish will need a separate breeding tank to hide from the intruders and lay their eggs.

Like the original tank, the breeding tank should have a minimum of 20-gallon capacity but with solid surfaces and the right elements to encourage breeding. Spawning mops and plants are some of the best options to include.

The right temperature for inducing the breeding process is between 68°F-74°F, but you should lower it to around 60°F at the start before increasing it again to the stated levels.

During breeding, it’s important to give your fish plenty of protein, such as worms and live brine shrimps that encourage effective spawning. After breeding, the adult fish will want to eat the eggs, so you should remove them from the tank as soon as you can.

Hatching will happen within 4-7 days, after which you can feed the little fish on powdered food until they are mature enough to eat brine shrimps or flakes. Also, baby Demekin Goldfish will have black or dark brown coloration, with the solid adult color only appearing after several months.

Final Thoughts

Telescope Goldfish might be a delicate species with protruding eyes, but their allure in a well-maintained aquarium is matchless. They are a unique fish species with specific requirements to help you understand if you are ready to introduce them to a community aquarium.

The fact they can live for up to 20 years in captivity makes Bugeye Goldfish a long-term investment that demands proper commitment from the start.

We hope this guide has covered everything you may have wanted to know about Telescope Goldfish care and that you are now ready to introduce a cute little Goldfish friend to your tank.