American Oceans

Glass Octopus

The glass octopus is one of many unique sea creatures. The elusive glass octopus has mystified scientists for decades.

a glass octopus swimming deep in the ocean

These creatures live deep in tropical and subtropical waters on the sea floor. 

The rarely seen glass octopus are tough to find so that scientists can study them.

Recently, the Schmidt Ocean Institute led an expedition to study these completely transparent sea creatures.

Marine biologists used an underwater robot to find glass octopuses. We will discuss the information that scientists learned with the underwater robot Subastian.

What Is the Glass Octopus?

A glass octopus, also known as Vitreledonella richardi, lives in the deep ocean. These elusive sea creatures are transparent, so they are challenging to find and study.

A few sightings and remains found in their predators were the only means of information about these cephalopods until the expedition led by the Smidt Ocean Institute.

Scientists discovered the glass octopus in 1918. The scarcity of these sea creatures made it challenging to learn about them until an underwater robot filmed two glass octopuses in the remote Pacific Ocean.

These sightings helped marine biologists at Woods Hole Oceanographic Institution understand how glass octopuses live and interact with their environment.

The underwater filming of these sea creatures gave scientists a wealth of information. The footage shows a glass octopus bared all for the world to see.

They were able to study their physical appearance, their surroundings, and their behavior. We will cover some of the things that scientists were able to learn.

Appearance and Size

The underwater robot allowed scientists to get a close-up look at two glass octopuses which was incredibly valuable in determining their appearance and everyday interaction with their deep-sea environment.


The glass octopus is one of the most unique sea creatures ever seen. Glass octopuses are almost entirely transparent, and you can see right through this creature in places.

There are three opaque parts on a glass octopus’s body: the eyes, optic nerve, and digestive tract.

The glass octopus’s eyes are cylindrical to help camouflage them from their enemies. The glass octopus does not change colors like many other species of the octopus because camouflage is not necessary.

These creatures are virtually invisible, making it harder for their predators to find them but much easier for them to hunt for prey.

The glass octopus’s body has a mantel and eight tentacles. They have six longer arms, while two are much shorter.

They have one extraordinary arm used for mating, and the glass octopus uses this arm to inject sperm into the mantle of the female glass octopus.

They have small evenly-spaced suckers that run in a single line on each arm. 


An adult glass octopus can measure up to 18 inches or 45 centimeters. Its mantle measures approximately 4.3 inches or 11 centimeters. 

The glass octopus has three pairs of arms which are longer than the fourth pair.

Compared to other types, like the giant Pacific octopus, which can measure close to 20 feet in length and weigh up to 50 pounds, the glass octopus is tiny.


The small and gelatinous glass octopus weighs about one ounce. These cephalopods can weigh even less depending on their size and age. 


The glass octopus feeds on crustaceans, fish, bivalves, and jellyfish. They are carnivores and cannot be too picky because their habitat limits their prey choice.

They typically hunt closer to the surface of the water at night when predators cannot see them. As the sun rises, these rare sea creatures will descend to the sea floor.

The sea floor offers snails, clams, and mollusks. The glass octopus will eat anything available to them.


You might know where glass octopuses live, but chances are still slim that you will catch a glimpse.

mariana trench deepest part of ocean

You can find a glass octopus anywhere in the world, as long as it is warm enough and the water is deep enough. These transparent sea creatures prefer tropical and subtropical waters. 

Glass octopuses hide in the depths of the deep sea. They live in the mesopelagic zone, an area from 656 to 3,280 feet under the surface.

They are sometimes down even further in the bathypelagic zone, which is 9,800 feet under the surface.

The glass octopus prefers an environment where there is no sunlight. 

Life Cycle

Scientists are working hard to collect information on the life cycle of the glass octopus. 

Life Span

Scientists estimate, with the limited information they have, that the glass octopus lives between two to five years.

The female glass octopus dies shortly after laying her eggs, a very short life cycle.

Breeding Habits and Offspring

The male glass octopus has a hectocotylus which is a detachable arm. Unlike other species of octopus, the glass octopus does not have a detachable hectocotylus.

Most species detach the arm and present it to the female. 

The glass octopus’s hectocotylus is a unique arm that can inject sperm into the female’s mantle.

The female has up to six months to use the sperm to fertilize the eggs. The eggs stay inside the female until they are ready to be born. 

The female will lay hundreds of eggs about 4mm in length. When the new glass octopus hatches, it measures 2,2mm in size.

Newborns are generally found closer to the surface and move down as they age. Hatchlings are left to care for themselves because the female glass octopus dies shortly after birth.

Newborn glass octopuses have a small beak that allows them to tear the skin from their prey.

They typically stay closer to the surface to hunt for food. As they grow, they lose this helpful beak, descend deeper, and begin feeding on softer organisms.

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