Daphne Breton

Daphne Breton

Modified & Updated: 02 Feb 2024

Source: Nationalgeographic.com

Barreleye fish, also known as spookfish, are fascinating creatures that inhabit the deep waters of the world’s oceans. These unique fish are named for their distinctive barrel-shaped eyes that protrude from the top of their transparent heads. With their unusual anatomy and behavior, barreleye fish have captured the attention of scientists and marine enthusiasts alike.

In this article, we’ll delve into the world of barreleye fish and explore 11 intriguing facts about these mysterious creatures. From their remarkable vision to their peculiar feeding habits, there’s so much to learn about these elusive deep-sea dwellers. So, get ready to dive into the depths as we uncover the secrets of the mesmerizing barreleye fish!

Table of Contents

The Barreleye Fish Has a Unique Transparent Head

One of the most fascinating facts about the Barreleye fish is its transparent head. This allows it to see above and below simultaneously, making it exceptional at hunting prey in the deep ocean.

They Have Tubular Eyes

Their eyes are positioned inside their transparent head and are tubular in shape. This adaptation helps them to focus on small sources of light, such as bioluminescent organisms, aiding them in their search for food.

Barreleyes Are Found in Deep Ocean Waters

These remarkable fish primarily inhabit the deep ocean, often found at depths of around 2,000 to 2,600 feet. They can be found in various regions, including the Pacific, Atlantic, and Indian Oceans.

They Have a Unique Feeding Behavior

The Barreleye fish uses its upward-facing eyes to scan for potential prey, while its tubular, sensitive eyes help detect any illumination produced by organisms or objects moving above them. This enables them to ambush their prey with precision.

They Are Small in Size

Barreleyes are relatively small compared to other deep-sea fish, growing to an average length of 6 inches. This size allows them to navigate through small spaces and explore their deep-sea environment with ease.

They Possess Bioluminescent Organs

Barreleye fish have specialized organs that emit bioluminescent light. These light-producing organs help attract smaller organisms, which the Barreleyes feed on.

They Have a Unique Jaw Structure

Their jaw structure allows Barreleye fish to have a wide gape, making it easier for them to capture their prey. Their mouth can extend forward, allowing them to consume larger organisms.

Barreleyes Can Rotate Their Eyes

This incredible species of fish has the ability to rotate its eyes within its transparent head. This adaptability gives them a wider range of vision and enhances their ability to detect potential threats or food sources.

They Have a Slow Swimming Speed

Barreleye fish are not known for their agility. They have a slow swimming speed, which allows them to conserve energy efficiently in the deep and often dark waters they inhabit.

Barreleyes Have Long Fins

Their long fins aid in their maneuverability and stability as they navigate through deep waters. These fins also help the Barreleye fish maintain balance and control while swimming and feeding.

They Are Considered Mysterious Creatures

Due to their unique characteristics and the depths at which they reside, Barreleye fish are considered mysterious creatures. Their transparent head, tubular eyes, and adaptations for deep-sea life make them a subject of fascination for scientists and marine enthusiasts alike.


In conclusion, barreleyes are truly remarkable creatures that continue to fascinate scientists and nature enthusiasts alike. With their unique adaptations and striking physical features, they have captured the attention of many. From their transparent heads to their incredible vision and feeding methods, barreleyes are a testament to the wonders of evolution.These deep-sea dwellers have adapted to survive in the harsh conditions of the ocean depths, making them well-suited for their environment. While there is still much to learn about these elusive creatures, their mysterious nature adds to their allure.Barreleyes serve as a reminder of the incredible diversity of life on our planet and the endless possibilities that exist within the animal kingdom. Studying and understanding these fascinating creatures will undoubtedly continue to shed light on the complex ecosystems that exist beneath the surface of our oceans.In summary, the barreleye is a true marvel of nature, showcasing the ingenuity and adaptability of animal species. The more we learn about these intriguing creatures, the more we realize how much there still is to discover and appreciate in the world around us.


Q: What is a barreleye?

A: A barreleye is a type of fish that belongs to the family Opisthoproctidae. They are deep-sea dwellers known for their transparent heads and upward-facing eyes.

Q: Where are barreleyes found?

A: Barreleyes are primarily found in the deep waters of the Pacific Ocean, particularly off the coast of California and in the waters around Japan.

Q: How do barreleyes feed?

A: Barreleyes have a unique feeding method. They use their transparent heads and upward-facing eyes to spot prey above them and then rotate their eyes forward to capture the food with their sharp teeth.

Q: Are barreleyes bioluminescent?

A: No, barreleyes do not possess bioluminescent capabilities. However, they are believed to have light-detecting pigments in their eyes, which help them navigate in the darkness of the deep sea.

Q: How deep do barreleyes live?

A: Barreleyes are found at depths ranging from 600 to 2,500 feet below the ocean’s surface. They inhabit the mesopelagic zone, also known as the twilight zone, where minimal sunlight penetrates.

Q: What is unique about barreleye eyes?

A: Barreleyes have highly specialized eyes that can rotate to face forward or look upwards through their transparent heads. This allows them to scan for prey and predators in the dark depths of the ocean.

Q: What is the purpose of the transparent head in barreleyes?

A: The transparent head of a barreleye serves to protect its delicate eyes while still allowing them to see. It is believed to provide camouflage and help them avoid detection from potential predators.

Q: Are barreleyes common?

A: Barreleyes are not very common due to their deep-sea habitat. They are also difficult to study and observe in their natural environment, which adds to their rarity.

Q: What is the size of a barreleye?

A: Barreleyes are relatively small fish, typically ranging in size from 6 to 10 inches in length, with some species reaching up to 15 inches.

Q: Can barreleyes be kept as pets?

A: No, barreleyes are not suitable for home aquariums. They have specific habitat requirements and are best left to their natural environment.

Q: Are barreleyes endangered?

A: There is currently not enough data to determine the conservation status of barreleye species. However, their deep-sea habitat and limited population make them potentially vulnerable to environmental changes and human impacts.