Rare 'Glass Octopus' Spotted in Deep Waters of the Central Pacific Ocean

A glass octopus (Vitreledonella richardi) possesses a nearly transparent body that is comparable to a living glass sculpture, hence the name. But little is known about this transparent animal and its population, in which the IUCN has listed it as a Species of Least Concern.

Encounters with this ocean species have been extremely rare primarily due to the nature of its habitat, according to the website Our Breathing Planet. Marine biologists believe that its transparent nature protects it from predators than traditional camouflage, rendering them almost invisible to prey and predators alike.

Now, this rarely seen glass octopus was spotted by an underwater robot gracefully soaring through the deep waters of the Central Pacific Ocean.

Rare Sighting of a Glass Octopus

Marine biologists were on a 3-4 day expedition aboard the research vessel Falkor when their underwater robot filmed the elusive glass octopus off the remote Phoenix Islands that is over 3,20 miles (5,100 kilometers) northeast of Sydney, Australia.

Only the eyes, optic nerve, and digestive tract of a glass octopus are opaque as they are almost completely transparent like other glass animals. According to Science Alert, the expedition crew encountered the glass octopus twice, which is an impressive feat given that they are elusive creatures. Due to the limited footage of these clear cephalopods, scientists had to learn about them by studying chunks of glass octopus in the gut contents of predators.

Glass octopus was first discovered and 1918, but still scientists knew nothing much about these transparent cephalopods except that they live in tropical and subtropical waters in the deep ocean.

A 1992 report published in the Journal of the Marine Biological Association of the United Kingdom described the eyes of the nearly transparent appearance of the glass octopus as part of its camouflage strategy. Its eyes most likely evolved to minimize its silhouette as seen from below.

During the team's expedition that ended last week on July 8, marine biologists also discovered some newfound marine animals on nine previously unexplored seamounts or mountains under the sea. The expedition allowed the scientists to document the rare sighting of the elusive glass octopus and discover areas where marine animals are protected.

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Other Glass Animals

The glass octopus is not the only transparent species in the animal kingdom. There are also other glass animals that use their transparent bodies as camouflage against predators.

BBC Earth listed some of these glass animals, such as the glass frogs that have green backs but translucent bellies, which shows their organs, bones, and blood vessels. Although it is not clear why their undersides are transparent, their green backs help them blend into the verdant leaf canopies where they live.

Another transparent animal is the moon jellyfish, which appears like a luminous globe in the light underwater. Its name relates to the four horseshoe-shaped organs that are visible through its umbrella-shaped body.

There is also the sea walnut (Mnemiopsis leidyi), which has no eyes or brain and looks like a transparent blob. Its common name is inspired by its apparent lifelessness, according to BBC Earth.