The deep sea just got a little spookier with the discovery of a ghostly octopod off the Hawaiian archipelago.

A remotely operated vehicle with the Okeanos Explorer, a National Oceanic and Atmospheric Administration ship, captured the pale cephalopod swimming slowly about 2.6 miles (4.3 kilometers) deep. (See "Weird New Ghostshark Found; Male Has Sex Organ on Head.")

Michael Vecchione, a NOAA zoologist working for the Smithsonian Institution, was excited when he saw the video pop up on the Explorer's live feed, which is also available online for the public.

"I knew it didn’t look like anything that’s been documented in the scientific literature," Vecchione says.

As well as probably being a member of a newfound species, the animal is unusual for another reason. It is the deepest-dwelling octopod—a group of invertebrates that includes octopuses—without fins ever found.Most deep-dwelling octopods, such as the "dumbo" octopod, have fins, he says.

Ghostlike Octopus Found Lurking Deep Below the Sea WATCH: Scientists are surprised to encounter what may be a never before seen octopus more than 4,000 meters (13,123 feet) deep in the sea near Hawaii. Video courtesy NOAA Office of Ocean Exploration and Research

Made for the Deep

Though the team only got a short video, the curious creature revealed certain adaptations for living in the deep.

For one, the octopus has very few muscles, and is almost gelatinous in consistency. This is likely because there's little food in the deep sea, and it takes a lot of energy to build muscles. (See "Huge Swarm of Gelatinous Sea Creatures Imaged in 3-D.")

What's more, its wraith-like appearance is due to a total lack of pigment cells, or chromatophores, which are useless in the dark depths. But the newfound creature's tiny eyes are probably functional, Vecchione says.

"When the sub got up close to it, it started climbing away, either reacting to lights of the sub or vibrations of the water," he says.

Its eyes may also help it see bioluminescent animals, which are common in the deep, he adds.

The ghost octopod shows we "don’t know much about what lives in the deep sea. Because we have some opportunities to explore, we’re finding these unexpected animals." (Download the app to watch Okeanos Explorer's live video from your mobile device.)

And among these, Vecchione says, "cephalopods are the coolest."