WATCH: Rare Clip of Elusive Deep Sea Giant -- Seven-Armed Octopus Devouring Helpless Jellyfish

Because of hundreds of bars of pressure and small amounts of oxygen, little is known about the creatures that thrive below the photic zone of the ocean.

As such, the clip of the elusive deep sea creature known as Haliphron atlanticus, a seven-armed octopus, feeding on its prey is being hailed by science as a magnificent finding.

In 2013, Biologists Henk-Jan Hoving (GEOMAR Helmholtz Center for Ocean Research Kiel) and Steve Haddock (Monterey Bay Aquarium Research Institute) remotely operated submersibles to explore the deep sea. Upon checking on what the equipment has "fished," the enigmatic seven-armed octpus appeared at 1,240 feet below the surface of the ocean in Monterey Submarine Canyon.

As shown by the clip, the seven-armed octopus was clinging on to the jellyfish with the latter's arms hanging out as it wades deeper into the ocean.

The researchers have analyzed the stomachs of five previously caught H. atlanticus, where they found gelatinous zooplankton and jellyfish, New Scientist reported.

Science Mag cited that in the clip, the jellyfish's organs were already missing, suggesting that the seven-armed octopus had already snacked on it. The H. atlanticus used its beak to bite through the "bell" of the jelly, and gulped all the nutrients inside the jellyfish's digestive cavity.

So why is it still carrying the nutrition-less jellyfish?

The researchers hypothesized that given that a dead jellyfish's tentacles are still capable of stinging, the seven-armed octopus was actually using the jellyfish's arms to collect more prey and possibly to defend itself from its own predators.

The clip is not only being held for its uniqueness but also for shedding new light on the diets of the elusive cephalopods.

National Geographic reported that H. atlanticus is commonly referred to as a "seven-armed" octopus because it keeps its eighth leg tucked into a space under its eye. In the last 27 years, since this new clip, there have only been three sightings of this mysterious deep sea giant.

The findings were published in the journal Nature.