Telescope Goldfish: The Unique Goldfish With Big Eyes

Telescope eye goldfish in a fishbowl

Telescope goldfish are like fish celebrities in the aquarium community. These fancy goldfish with big eyes are known not only for their appearance but also for their peaceful demeanor.

Nonetheless, if you plan to add these fancy goldfish to your community tank, you should know that they require specific maintenance and care.

Luckily, we just got everything covered for you! This guide will discuss everything you need to know about telescope eye goldfish, from their characteristics and behavior to their unique needs and price. Let’s start.

Telescope Goldfish Quick Facts

Common Names:Telescope goldfish, telescope eye goldfish, Demekin (Japan), dragon eye goldfish or dragonfish (China)
Unique Traits:Large, protruding eyes resembling telescopes; long, flowing tails; more rounded or egg-shaped body compared to other fancy goldfish
Origin:Originated from China in the early 1700s, further developed in Japan in the late 1700s
Lifespan:10–20 years
Adult Size:4–8 in (10–20 cm)
Tank Size:20–30 gals for a single fish; an additional 10 gals for every additional goldfish
Temperature:65–75°F (18–25°C)
pH Level:6.5–7.5
Care Level:Intermediate
Price Range:$15–$100
Recommended Tankmates:Other slow-moving fancy goldfish and peaceful species with similar care requirements

What Is a Telescope Goldfish?

Telescope eye goldfish isolated on white background

The telescope goldfish is a unique variant of goldfish, scientifically known as Carassius auratus. These fancy-looking goldfish share traits with their common variant cousins, except that they have distinctively large, protruding eyes; hence, their name.

In Japan, telescope goldfish are called Demekin until today, while they were originally referred to as dragon eye goldfish or dragonfish in China.

This breed first emerged in China in the early 1700s and is one of the many goldfish variants, including the black moor, panda moor, and celestial eye.

They are products of selective breeding practices in China and were developed to accentuate their eye protrusions, making them one of the most heavily hybridized goldfish varieties after the fantail goldfish.

Telescope eye goldfish were initially introduced to Japan, where they were further bred and developed until they made their way to the United States and the rest of the world.

Despite their striking looks, they require specialized care due to their poor vision and the risk of injury from tank decorations and equipment.

They are slow swimmers and can struggle in environments with strong currents or with tank mates that are faster and more agile. Hence, ensuring a safe and accommodating habitat is crucial for their well-being.

Physical Characteristics

Black dragon eye goldfish

Telescope goldfish are distinguished by their prominent, bulbous eyes, which protrude significantly from the sides of their heads. These unique features develop as the fish matures.

Their body is rounded or egg-shaped, similar to other goldfish variants. They also come in several fin and tail variations, with some displaying long, flowing fins. They can grow between 4 and 8 inches long.

The colors of telescope goldfish also vary widely, including solid colors like red, chocolate, blue, and white and multi-colored patterns such as tri-color, calico, and bi-color varieties.

Despite the range of physical appearances, all telescope goldfish share the characteristic egg-shaped body and protruding eyes.

Here is what a year-old telescope eye goldfish looks like:

Telescope Goldfish | 1 Year Later

Varieties of Telescope Eye Goldfish

Butterfly moor telescope fancy goldfish

Telescope eye goldfish are a captivating breed within the fancy goldfish family, celebrated for their unique, bulbous eyes that seem to gaze curiously at the world around them.

These varieties differ in color, fin shape, and size, each bringing charm to aquariums worldwide. Here’s a look at their distinctive traits:

  • Black Moor: Recognized by their velvety black bodies, black moors are among the most popular telescope eye varieties. Contrary to popular belief, their deep, rich color can fade as they age or due to environmental conditions, usually turning gray, orange, or red.
  • Panda Telescope: This variety stands out with its black-and-white pattern, resembling a panda. The contrast of colors highlights their distinctive eye shape and body form. However, their unique coloration may change over time, often transitioning toward more monochromatic hues as they mature.
  • Butterfly Telescope: A newer addition to the telescope family, butterfly telescopes boast a stunning double tail that spreads like butterfly wings. Their flowing fins and graceful swimming make them a mesmerizing sight.
  • White Telescope: With their pristine, solid white bodies and contrasting large, protruding eyes, white telescopes offer a serene beauty. They share similar care needs with darker counterparts but are less common, adding a rare elegance to any collection.

While their beauty is undeniable, providing an environment that caters to their needs is crucial, considering their vision limitations and susceptibility to environmental stresses.

Temperament and Behavior

Close up of a telescope eyed goldfish

Telescope eye goldfish are recognized for their gentle and peaceful nature. These fish thrive in social settings, often seen scavenging for food alongside their tankmates without displaying any aggression.

Their unique physical feature, the protruding eyes, does not hinder their sociability but does require that they be kept with other non-aggressive fish to avoid injury.

Telescope goldfish are active swimmers who like to explore all tank areas. However, they will seek out hiding spots among plants and decorations when feeling threatened or needing rest.

Despite their active demeanor, they also have rest periods, where they might hover near the bottom of the tank, especially during the day.

Recommended Tankmates for Telescope Goldfish

As established, telescope goldfish are peaceful. To ensure a harmonious community tank, they require equally sociable and calm tankmates.

Generally, they do well with other non-aggressive fish that won’t compete aggressively for food or space.

Avoid species known for fin-nipping or those significantly larger or more aggressive, which could stress or harm the telescope goldfish.

Some suitable tankmates for telescope goldfish include:

  • Other fancy goldfish variants
  • White cloud mountain minnows
  • Bristlenose plecos
  • Corydoras
  • Otocinclus fish
  • Glass catfish
  • Loaches
  • Hoplo catfish
  • Danios
  • Japanese rice fish
  • Rosy barb

These species are compatible with telescope goldfish due to their peaceful nature, similar size, or ability to occupy different tank regions without interfering with each other.

It’s essential to ensure that the tank is adequately sized to accommodate all inhabitants comfortably and that the environment (such as water temperature, pH, and hiding spots) meets the needs of all species present.

If you are thinking of adding invertebrates, such as shrimps and snails, to your aquariums, just make sure they aren’t small species that could fall prey to your telescope goldfish.

Cherry shrimp and mystery snails are perfect scavenging partners for these big-eye fish.

Telescope Eye Goldfish Care Guide

Telescope goldfish in fishbowl

Telescope eye goldfish share similar care requirements with other goldfish variants. Generally, they are manageable and easy to care for. They only need ample space, stable water conditions, and a healthy diet.

However, their unique trait — large, protruding eyes — affects their vision, consequently affecting their swimming and ability to compete for food. They need to be monitored regularly to ensure they are thriving.

Lifespan and Common Diseases

Telescope goldfish, with proper care, can live a long life, ranging from 10 to 20 years, and some even live longer in well-maintained tanks or ponds​​​​​​.

However, like all fish, telescope goldfish are susceptible to common diseases that can impact their lifespan. Awareness of these diseases is critical for prevention and early detection.

Here are some of the common illnesses telescope eye goldfish can develop:

  • Ich (White Spot Disease): This disease is easily identifiable by small, white, grain-like spots covering the fish’s body, fins, and gills, resembling sugar granules. The parasite Ichthyophthirius multifiliis causes ich. Infected fish may show signs of irritation, lethargy, and difficulty breathing if gills are affected.
  • Fin Rot: Fin rot presents as a fraying or rotting away of the fish’s fins, often starting at the edges and moving inward. It can be caused by a bacterial infection that takes hold due to poor water quality or an injury. The fins and tail may become milky or bloody in appearance. 
  • Dropsy: Dropsy is not a disease but a symptom of a systemic infection, leading to fluid accumulation and swelling of the fish’s body. This causes the scales to stand out, giving a pinecone-like appearance. The underlying causes can be varied, including bacterial infections, parasites, or liver dysfunction.
  • Swim Bladder Disease: This disorder affects the fish’s ability to regulate its buoyancy, leading to floating at the top or sinking to the bottom of the tank. Causes can include genetic defects, overeating, rapid eating leading to ingested air, or constipation blocking the swim bladder.

For telescope goldfish, maintaining optimal tank conditions, including regular water changes, proper filtration, and a balanced diet, is crucial in preventing these diseases.

Observing your fish daily for signs of distress or unusual behavior can help catch issues early, significantly increasing the chances of successful treatment.

Tank Size and Water Parameters

The aquarium setup plays a crucial role in maintaining the health of telescope goldfish. These goldfish are known not only for their unique appearance but also for their specific aquarium needs.

A telescope goldfish requires a minimum of 20 gallons of water. To ensure each fish has enough room to swim and thrive without stress, it is advisable to add an extra 10 gallons for every additional goldfish.

Water quality and parameters are equally important for maintaining a healthy environment for telescope goldfish.

The ideal water temperature should be between 65°F and 75°F, which aligns with their natural habitat preferences. The pH level is best maintained within a neutral range between 6.5 and 7.5.

Regular checks on ammonia, nitrite, and nitrate levels are essential to keep ammonia and nitrite at zero and nitrate low. This can be achieved through consistent water changes and a reliable filtration system.

For my goldfish tank, I stick with changing 25% of the tank water every two weeks. This is to ensure that the quality of the water is healthy enough for the fish while keeping the natural cycle maintained and balanced.

Besides adding to the aesthetic, I also add aquatic plants like Java Fern and Anubias for natural filtration.

However, I recommend adding only a few plants as telescope goldfish can get trapped in dense vegetation. Remember, these fish have poor vision and need ample swimming space.

Diet and Feeding

As omnivores, their diet should include plant-based and meaty foods to provide balanced nutrition.

High-quality goldfish pellets or flakes should form the staple of their diet, supplemented with live or frozen foods like brine shrimp, daphnia, and bloodworms for protein.

I also include vegetables such as zucchini, peas, and spinach, which aid digestion and prevent constipation, a common issue among fancy goldfish.

Before feeding my goldfish veggies, I boil or blanch them until they are soft enough to nibble to avoid blockage and indigestion.

Feeding should occur 2 to 3 times daily, with portions small enough for the fish to consume within a few minutes to avoid overfeeding and subsequent tank pollution.

You should also consider the poor eyesight of telescope goldfish. You can opt for sinking pellets to ensure they can find their food easily.

How Much Does a Telescope Goldfish Cost?

Young telescope goldfish

The cost of a telescope goldfish varies depending on several factors, including size, color variation, and quality.

Generally, prices can range from as low as $15 for smaller, more common varieties to over $100 for larger, show-quality specimens with rare color patterns.

It’s important to remember that while the initial cost of the fish might be moderate, setting up a proper tank environment and ongoing care can add additional expenses.

Telescope goldfish are available at various places, including local pet stores, specialized fish or aquarium stores, and online retailers like LiveAquaria and King Koi and Goldfish.

When purchasing online, choosing reputable sellers who offer healthy fish and safe shipping practices is crucial to ensure your new pet arrives in good condition.

Before buying a telescope goldfish, consider the ongoing costs of maintaining a suitable aquarium, including a large enough tank, filtration system, proper diet, and potential veterinary care.

Breeding Telescope Goldfish

Telescope eye goldfish swimming in aquarium

Breeding telescope goldfish is a rewarding but intricate process. These goldfish are egg-layers, requiring a specific setup and conditions to encourage spawning.

To start breeding, you should identify mature fish; males show breeding signs through tubercles on their gills and fins, while females have a fuller body shape.

A specialized breeding tank is essential, equipped with a sponge filter to replicate calm waters and furnished with plants or spawning mops for egg deposition.

The temperature should be carefully managed. To induce spawning, slowly drop the regular temperature to 60°F and gradually increase it daily to simulate the temperature change, similar to spring.

The stable temperature should fall between 65°F and 75°F to trigger their breeding behavior.

Once eggs are laid, they must be relocated to a fry tank to protect them from being eaten by adult goldfish. You should expect the eggs to hatch within a week.

Early on, the fry does not require feeding, but as they start swimming actively, they should be fed a high-protein diet to ensure proper growth. This diet can include finely ground fish food or specially prepared egg yolk.

Frequently Asked Questions

Goldfish with protruding big eyes in a blue aquarium

Are Telescope Goldfish Aggressive?

Telescope goldfish are known for their peaceful and sociable nature, making them excellent community tank inhabitants. They do not exhibit aggression towards other fish, especially those of similar size and temperament.

Are Telescope Goldfish Hardy?

Telescope goldfish are moderately hardy and adaptable to various tank environments. They thrive in well-maintained water conditions and require regular care, including proper filtration and a balanced diet.

However, their distinctive large eyes make them more prone to injury and disease than other goldfish varieties. Careful attention to tank setup and water quality can help mitigate these risks.

Do Telescope Goldfish Get Along With Other Fish?

Telescope goldfish are peaceful and get along well with other non-aggressive fish that share similar water condition needs. Their calm nature makes them suitable tank mates for many community fish. 

How Many Telescope Goldfish Should Be Kept Together?

Ideally, keeping at least two telescope goldfish together allows for social interaction, contributing to their overall health and well-being. Nonetheless, the number of fish you can keep together depends on the tank size.

It’s important to remember that goldfish produce significant poop and waste, requiring ample tank space to maintain a clean and healthy environment.

A general rule is to provide at least 20 gallons of water for the first fish, with an additional 10 gallons for each subsequent fish. This guideline prevents overcrowding and ensures each goldfish has enough space to thrive. 

With their unique looks, calm behavior, and ease of maintenance, telescope goldfish can be excellent additions to community tanks. Do you have more questions about these big-eyed fish? Leave a comment below!

Leave a Comment

You may also like