Deep sea exploration just turned a little spookier – or cooler – with the discovery of a "ghost octopus," a new species that may be the deepest-dwelling of its kind.

Deep Discoverer, a remotely operated vehicle of the Okeanos Explorer or a ship of the National Oceanic and Atmospheric Administration (NOAA), caught on video a pale cephalopod swimming leisurely at 4,290 meters (14,074 feet) deep. The dive occurred northeast of Necker Island in Hawaiian archipelago.

NOAA zoologist Michael Vecchione from the Smithsonian National Museum in Washington, D.C. spotted the mysterious creature while the underwater vehicle was collecting sediment samples. He knew right away that the sighting was out of the ordinary.

"The appearance of this animal was unlike any published records and was the deepest observation ever for this type of cephalopod," he says. Cephalopods are deemed the largest, most mobile and intelligent of all mollusks, which comprise octopuses, squids and cuttlefish.

Apart from likely being part of a newfound species, the ghost-like octopus is considered the deepest-dwelling octopod without fins. In contrast, the "dumbo" octopod and most other deep-dwelling animals of this kind maintain fins on the sides of their bodies.

Given its similarity with the shallow-water octopus and its lack of fins, this particular octopus then might as well be an incirrate octopod, wrote Vecchione. Incirrates have never been previously detected at such depths, only at less than 4,000 meters (13,123 feet).

Two unusual qualities make the octopus stand out: its ghostly appearance, contrary to most other cephalopods exhibiting pigment cells known as chromatophores, as well as a lack of musculature. A social media user who has seen the NOAA video even christened the octopus as Casper, the popular friendly ghost.

The pigment cells, however, are practically useless in the dark depths; although the creature's small eyes probably remain functional.

Vecchione, who along with his colleagues are planning to combine their new observations with those of a German cruise in the eastern Pacific, said it is most likely an undescribed species and many belong to an entirely new genus.

With much of the deep sea remaining unexplored, it is hardly surprising for scientists to discover previously unknown life. In 2014, for instance, a ghostly fish with wing-resembling fins was found more than 8,000 meters (26,246 feet) deep, setting the record for the deepest living fish.

"The more time we spend at deeper depths, or in the deep water column, the more likely we are to come across something unexpected," Vecchione says.

ⓒ 2021 All rights reserved. Do not reproduce without permission.