Telescope Fish: Wiki, Interesting Facts & Other Questions

Featured Image Credits: Emőke Dénes (commons.wikimedia) (CC BY-SA 4.0)

Little aulopiform fish are found in the deep water; the family Giganturidae includes the Telescopefish. The genus Gigantura has two recognized species. They inhabit cold, deep, tropical, and subtropical seas all across the planet but are rarely caught.

These fish’s eyes’ peculiar, tubular shape inspires their famous name. The genus Gigantura gets its name from the giants of Greek mythology, the Gigantes, and the suffix oura, which means “tail,” to indicate that the long, ribbon-like base of the tail fin may account for more than half of the animal’s entire length.

The giant eye lenses of the Giganturidae are the dominant feature of their vast, forward-facing heads. They have short, pointed snouts instead of ears.

The mouth is vast, extending well past the eyes, lined with sharp, somewhat recurved, and depressible teeth.

The lack of scales is made up for by a covering of silvery guanine that, in life, gives the animal a greenish-to-purple iridescence. Both the gas bladder and the distensibility of the stomach are lacking.

In this post, we’ll introduce you to the Gigantura sp., or Telescopefish, also known as the Gigantura chuni, and provide you with ten interesting facts about this fascinating animal. Therefore, without further ado, let’s dive into this subject.

Telescopefish: Wiki

Scientific Name Gigantura Sp. 
Common Name Gigantura chuni or TelescopeFish
Size The Telescopefish can grow up to 9 inches (23 cm) in length.
Habitat Atlantic, Pacific, and Indian Oceans are the primary habitat of this fish.
Diet The Telescopefish is a predatory fish, feeding on small fish and crustaceans.
Predators Larger fish, such as tuna and marlin, prey upon the Telescopefish.
Colors The Telescopefish is a dark brown or blackish color.
Weight The Telescopefish typically weigh around 1 pound (0.5 kg).
Life Span The Telescopefish has a relatively short lifespan, living for only around five years.
Price The price of a Telescopefish can vary depending on the location and availability, but they are generally not commonly sold fish in the aquarium trade.
About It The Telescopefish is named for its large, tubular eyes that are directed upwards, giving it a “telescopic” view of its prey above.

It has a unique body shape, with a compressed and elongated body, and can change its coloration to blend in with its surroundings. Due to its deep water habitat, little is known about the Telescopefish’s behavior and ecology.

Giant (about 30-42 rays), horizontally inserted, and located above the gill opening, the pectoral fins are a distinguishing feature of this species.

The transparent fins lack spines, and the most distinctive feature is the caudal fin, which is deeply forked and hypocercal, with a lower lobe that extends to a length more significant than the body.

Both the anal fin (consisting of around 8-14 rays) and the solitary dorsal fin (consisting of about 16-19 beams) are located below the fish’s brain. There is no evidence of pelvic or adipose fins.

The gill rakers, branchiostegal rays, and premaxilla are also missing, along with the orbitosphenoid, parietal, symplectic, posttemporal, and supratemporal bones.

Retaining larval features, or neoteny, is thought to be to blame for the disappearance of these structures. The Gigantura indica is around 20 cm in standard length, making it the length of the two species (a measurement excluding the caudal fin).

Gigantura chuni, on the other hand, is significantly more robust in construction and size (15.6 cm standard length). Telescopefish are solitary, aggressive predators that live between 500 and 3,000 meters deep.

Telescopefish can detect their prey’s faint bioluminescence from a distance and resolve the silhouettes of prey against the darkness above thanks to their tubular, large-lensed eyes adapted for optimal binocular light collection.

Like deep-sea fish, Telescopefish have specialized eyes that detect prey at great distances (barrel-eye, tube-eye). Bristlemouths, lanternfish, and barbeled dragonfish are common targets.

Their reproductive habits also need to be understood. They are thought to be pelagic spawners who don’t bother protecting their eggs and instead scatter them randomly.

10 Interesting Facts About Telescopefish

Large eyes give them a “telescopic” look, making them appear alien and strange. Some have masks on their faces and beaks like birds or fish, while others have feathery antennae.


View this post on Instagram


A post shared by Joe Rogan (@joerogan)

1. They Have Some Intelligence:

Telescope fish are stereotyped as stupid because of their out-of-the-ordinary appearance and location on Earth. Nonetheless, their brain size is disproportionate to their body size.

Their brain size is disproportionate to their body size. The size of their brain is comparable to that of a domestic cat.

Another sign of their superior intelligence is the elaborate social system they’ve constructed. Many researchers have focused on this social organization because of its similarities to that of ant or bee colonies.

2. They’re Able To Play Host To A Variety Of Animals:

Telescope fish frequently take advantage of their hosts as parasites or act as hosts themselves. This may look like a parasitic relationship, but it is healthy and mutually beneficial.

Barnacles, which feed on fish waste, are a common resident. The fish can clean their skin by scraping off the barnacles, and the barnacles can survive by eating the slime that accumulates on the fish.

This is a long-term partnership that can potentially improve the lives of its participants.

3. They can see clearly in the dark because of their special eyes:

The big, intense blue eyes of a telescope fish are distinctive. Their eyes contain so much melanin pigment that they can see in the dark.

Due to water’s high absorption of visible light, visibility is diminished below the water’s surface compared to the open ocean.

4. They develop the ability to switch genders after being born males:

The sex differences between male and female telescope fish are striking. The males have longer, fluffier antennae than the females, who have shorter ones.

Males have the remarkable ability to transform into females as adults, which is quite unusual among animals. This unique event occurs because it is difficult for male telescope fish to find a mate in their dim habitat.

The male fish can undergo a metamorphosis into a female, giving it shorter antennae and making it more attractive to potential partners.

5. Bioluminescent whiskers are a feature of these creatures:

The telescope fish’s “whiskers” are luciferins, biological chemicals. These chemical elements are the same as those used to make fireworks and glowsticks.

The telescope fish’s delicate whiskers aid it in its prey pursuit and dodging predators like sharks.

6. They are Professional Cleaners:

Telescope fish are fascinating for more reasons than one, but one of the most intriguing is that they are cleaning experts.

Because of this, species like sharks are fair game for them because they enjoy eating their parasites and shedding skin. The shark gets a complimentary bath, and the telescopic fish gets a tasty dinner from the arrangement.

7. They Use a Special Defensive System

When threatened, telescope fish use a unique defense mechanism. The fish will release a cloud of glowing bubbles if it is attacked.

The predator is diverted from the fish by the bubbles’ luminescence. This fascinating defense strategy is exclusive to telescope fish. The telescope fish will shoot off its fin to distract a predator.

Not many fish can shoot off their fins as a defense mechanism, making this a unique and fascinating trait of telescope fish.

8. They are Quick swimmers:

Telescope fish speed has not been quantified in any research. Nonetheless, they have been observed to swim in tightly knit groups that move at high speeds.

9. They live in more considerable depths:

The telescope fish lives at depths of 0.7 to 1.3 kilometers. These fish inhabit intense, black seas, far from any natural light sources.

Nature has provided the telescope fish with tubular eyes that protrude from the skull like a pair of binoculars to compensate for this disadvantage.

10. Can be kept in Aquarium:

While they are considered little fish, telescope fish can reach a maximum length of 3 inches. Despite needing a particular diet, this makes them simple to maintain in an aquarium.

Being omnivores, telescope fish consume both plant matter and insect larvae. The telescope fish’s distinct appearance and varied behavior make it a popular addition to home aquariums. It’s worth noting that telescope fish need special diets and aquarium conditions to thrive.

Other Facts:

  • The mouth and jaw of a telescope fish may stretch, making it an effective instrument for capturing prey in a hurry.
  • Telescope fish’s distribution, lifespan, appearance, nutrition, etc., little is known because they are so far from human grasp.
  • They typically swim in a synchronized fashion.
  • Gestures, vibrations, movements, and body language are all communication components.
  • There are no sex-specific names for fish, unlike many other marine organisms.

In conclusion, the fascinating world of the Telescope Fish offers a captivating glimpse into the wonders of aquatic life. With their unique physical features and intriguing behaviors, these fish have captured the imagination of both scientists and aquarium enthusiasts alike.

The distinctive protruding eyes of the Telescope Fish not only give them their name but also serve as a remarkable adaptation that enhances their ability to navigate their watery environment.

These large, bulbous eyes provide an expanded field of vision, allowing them to detect predators and locate food more effectively. Furthermore, the vibrant colors and graceful movements of these fish make them a visually striking addition to any aquarium.

Beyond their appearance, the Telescope Fish exhibit interesting social behaviors, forming schools and engaging in courtship displays. Their peaceful nature and compatibility with other fish species make them popular choices for community tanks.

However, it is crucial to consider the care requirements of Telescope Fish before keeping them as pets. Due to their unique anatomy, they may be more susceptible to certain health issues, such as swim bladder disorders.

Providing appropriate tank conditions, including spacious environments and balanced nutrition, is essential for their well-being.

Studying and appreciating the Telescope Fish not only enriches our understanding of aquatic biology but also reminds us of the astounding diversity found in the world’s oceans and freshwater habitats.

As we continue to explore and conserve these ecosystems, the Telescope Fish serves as a captivating ambassador, captivating us with its mesmerizing appearance and contributing to our fascination with the marvels of the natural world.

Frequently Asked Questions

Q1. How deep do telescope fish live?

The Telescopefish can be found worldwide in shallow to deep tropical and subtropical waters (500-2000 meters).

Q2. Can telescope fish see?

Nature has provided the telescope fish with tubular eyes that protrude from the skull like a pair of binoculars to compensate for this disadvantage. This adaptation allows the fish to hunt in the darkest parts of the mesopelagic. The fish’s specialized vision helps it locate prey.

Q3. What do telescope fish eat?

Bristlemouths, lanternfish, and barbeled dragonfish are common targets.

Q4. Can we eat Telescope fish?

Telescope fish are safe for human consumption but are often difficult to find.

Q5. What is the telescope fish price?

The price of a Telescopefish varies from Rs. 100 to Rs.1,000. Several factors affect how well Telescopefish perform.


  • Telescope Fish facts by AZ Animals
  • Telescope Fish: Everything You Need to Know by
  • Wikipedia

Also Read: