The exotic inhabitant of the tropical seas lives at great depths and is almost completely transparent.
Scientists from the Schmidt Institute of Oceanology (USA) have published a video made by the SuBastian underwater robot near the Phoenix Islands (Kiribati). With its help, for the first time, it was possible to obtain a high-quality video of an unusual octopus living at depths of up to a kilometer and never rising into near-surface waters, where scuba divers could observe it.
This species is called the "glass octopus": it is indeed mostly transparent, with the exception of rectangular eyes, part of the nervous and digestive systems. Because of this, the animal has a surreal appearance that has no analogues in the animal kingdom.
Glass octopuses (Vitreledonella richardi) live at a depth of 1.0 to 0.2 kilometers, so it is extremely difficult to study them: it is extremely difficult for scuba divers to work deeper than 100 meters. Usually, such deep-sea creatures are studied by their remains in the stomachs of predators caught by trawls, and direct observation of them in nature is a rare success. This time, the researchers used a deep-sea robot capable of observing even where it is almost impossible for humans.
This octopus species has almost rectangular eyes, a mantle about 11 centimeters in size, and a total body length of just under half a meter for adults. The males use the third left tentacle for fertilization. Unfortunately, little is known about the species' lifestyle.
Females of other species of deep-sea octopuses (and they are found at depths of up to seven kilometers) spend a lot of time next to their eggs, constantly ventilating the place where they develop. Sometimes this time reaches several years, since the depths of the seas are very cold, and the development of eggs there is slow. It is not entirely clear how long this process takes for glass octopuses.
In addition to glass octopuses, the deep-sea robot was able to capture a number of other unusual creatures, including whale sharks reaching 12 meters in length. You can see a video with a cut of what he shot below.
The most likely reason for transparency in many marine species is considered to be camouflage: the fewer clearly visible body parts, the more difficult it is for predators to detect them. In the case of the glass octopus, camouflage helps it protect itself not only from predators, but also from detailed study by scientists.