The never seen before Spirula squid, in its natural habitat

For the first time, a live curly-shelled squid (Spirula spirula) has been captured cruising in its natural habitat.

This peculiar-looking cephalopod is no more than 7 cm long, has eight arms, two tentacles, a pair of bulging eyes, and generally looks like a Muppet.

At the tail end, hidden beneath the coat, is a tightly coiled inner cavity shell that contains air pockets - which are manipulated to sink and float.

A live video was taken from the Great Barrier Reef at a depth of 850 to 860 meters. At first, the researchers operating the ROV, a diving robot at the Schmidt Institute of Oceanography, didn't realize what it was. One scientist exclaimed, "What the hell is that?"

The rare sighting has since been shared online and has been confirmed as the first footage of a live Spirula found in the deep sea, the largest and least explored habitat on our planet.

While there are many more deep-sea species that we don't know about, this beautiful encounter has scientists excited. 

Aside from the cuttlefish, it is the only mollusk that contains an inner cavity shell. But unlike the cuttlefish, this squid's skeleton is tightly coiled; mollusks of the genus Nautilus have similarly shaped shells, but are instead on the outside of the animal.

Although Vecchione often catches the species from the deep sea, sometimes housing them in aquariums, he had never before seen a picture of a live Spirula in its natural habitat. Neither had Neige Pascal, who studies the Spirula at the University of Burgundy in France. He told ScienceAlert that the video is "Very exciting."

In addition to the rare footage, there is one particularly surprising aspect to it: the animal's position in the water - its head and tentacles float upright, while its fins point down.

"Can someone tell me if the diving robot's camera is mounted backwards? If that's not the case, it's a disruptive discovery in the cephalopod discipline." Pascal said.

His doctoral student Morgane Oudot, one of the few researchers in the field, agrees and says the video had made her question what she had learned.

"A lot of people freaked out because the head was up - they freaked out because the airbag was at the end of the squid. So the heavier head looks like it should be facing down."

In fact, the curly-shelled squid that we keep in our aquariums has a large head facing downward. It was therefore taken for granted that the species would adopt the same posture in the deep sea.