Recently, researchers in the U.S. Pacific Remote Islands Marine National Monument acquired live footage of the glass octopus, getting a closer look at these highly elusive and fascinating creatures. According to Live Science, the scientist spotted two glass octopuses using a remotely operated vehicle (ROV). To date, this is the most important sighting of this creature, adding a great deal to scientists’ understanding of their lives and the overall understanding of our ocean.

Previous to this incredible sighting, the knowledge scientist had about glass octopuses was limited to what they could derive from the remains of the creatures in predators’ digestive tracts. Now, the scientific insights are far greater.

Using technologies such as the ROV, or others like resolution seafloor mapping, to find transparent species like the glass octopus is a remarkable example of the frontiers of science.

Marine biologists believe that the glass octopus evolved to be nearly transparent in order to hide from predators to the best of its abilities. No light from the sun reaches the depths at which the glass octopus resides. This, in tandem with their unique glass-like bodies, helps the octopuses evade predators. 


Appearance 

The glass octopus is a transparent bathypelagic octopus that has a mantel of around 4.3 inches or 11 cm in length. The total length of an adult specimen is around 18 inches or 45 centimeters. The octopus has eight tentacles. The upper three pairs are mostly equal in length. The fourth pair of arms, or the ventral pair, is shorter. The longer legs are usually around two to three times the length of the mantle in adults. There are small, widely spaced suckers on their arms in a single line.

The most interesting feature of the octopus is its nearly transparent body. If one is lucky enough to see this creature, they’ll notice immediately that it’s possible to see straight through to it in most places. The only parts of the octopus’s body that are not completely transparent are its eyes, optic nerve, and digestive tract. This makes these opaque elements of their bodies stand out.

Their eyes are elongated and rectangular in shape, at least when viewed from the side. Their eyes can, since they are not transparent, help predators track down the glass octopus as prey. Scientists believe that they have evolved into their elongated shape in order to make the octopus camouflage, and even less visible when seen from above.

Video of the glass octopus as captured by the underwater robot SuBastian

 

Diet 

Glass octopuses are thought to eat crustaceans, like most of their relatives. These include marine snails, small clams, and mollusks. It’s likely that these octopuses eat whatever is available to them in the depths of the mesopelagic and bathypelagic zone. It is believed that in the paralarvae stage of development, they gradually move into the deep ocean and feed on softer-bodied prey. Whereas, before this stage, the young glass octopus has a beak to assist in tearing the skin of its prey.

Examples of fish living in the deep sea
Examples of fish living in the deep sea


Habitat 

These octopuses live in tropical and subtropical waters around the world. Generally, they reside in deep areas of the ocean that are hard to reach, around 656-3,280 feet. This is known as the mesopelagic zone, or the twilight zone. They are also thought to live in the bathypelagic zone, or midnight zone, which reaches down to 9,800 feet (or 3,000 meters) below the surface, according to the ICUN. 

Diagram of ocean zones
Diagram of ocean zones


Reproduction 

Like all octopuses, the male glass octopus has a hectocotylus. That is a modified arm that transfers sperm into the female’s mantle cavity. They are believed to have a non-detachable arm. This means that they cannot detach the arm and present it to their mate, unlike other species. As noted above, little is known about these creatures’ habits. But, they are thought to live to be around two to five years old. 

The female glass octopus lays hundreds of eggs at a time. When born, the eggs are around 4 mm in length, according to Octolab.

Illustration of a glass octopus
Illustration of a glass octopus


Threats

The transparent glass octopus is so rarely spotted, and so little is known about the creature that it’s unclear exactly how many examples of the species exist. Generally, creatures that live thousands of feet under the surface of the ocean are safer from human causes and changes to the global environment, raiding the least concern in terms of their threat of extinction. These deep-sea communities tend to avoid the majority of risks. For example, warming ocean temperatures, pollution, habitat encroachment, overfishing, trolling, or the depletion of food sources.

Facts about the Glass Octopus

  • Sightings of the glass octopus are incredibly rare. 
  • The glass octopus is nearly entirely transparent. 
  • Only its eyes, optic nerve, and digestive tract are opaque. 
  • The octopus lives in the mesopelagic and bathypelagic zones. 
  • It eats crustaceans, like mollusks and snails.
  • Their eyes have evolved into an elongated shape to make them less visible from above. 


FAQs 

What do glass octopuses look like?

Glass octopuses are small, nearly transparent octopods. Only their digestive tracts, eyes, and optic nerves are opaque. They float gracefully through the water, seeking out small prey like mollusks. They have eight legs, two of which (the ventral legs) are smaller. The six larger legs are approximately twice the length of the octopus’s mantle. 

Is the glass octopus real?

Yes, the glass octopus is a real octopod that lives in the depths of the world’s tropical and subtropical oceans. These octopuses are rarely seen, but when they are, the footage displays a nearly transparent, small creature that is incredibly interesting.

Is the glass octopus endangered?

It’s not considered to be endangered. Although it’s rarely seen, it’s believed to live widely in the depths of tropical and subtropical waters. As scientists learn more about these creatures, it will become clearer the state of their population numbers throughout the world. But, all of Earth’s animals are at some threat from habitat changes.

How big can octopuses grow?

The largest octopus, the giant pacific octopus, can grow to around 30 feet from the tip of one arm to another. Other octopuses are far smaller, like the Octopus wolfi, which can only grow to around an inch or 2.5 centimeters. 

How much does a glass octopus weigh?

They weigh around one ounce, or even less, depending on their size and age. When they first hatch, they are tiny. They need their various adaptions, like their transparent skin, in order to evade predators. 

Featured image credit: Live Science