Mysterious and elusive sighting of a giant fin squid filmed by deep-sea explorers

At CNET Science, we tend to focus a lot on worlds and life beyond Earth. We love space. The hellish lava planets is the icy moons of our solar system they are intriguing and unexplored places that hold many secrets. This makes it easy to forget that we are hiding a vast and mysterious world beneath the surface of our oceans, arms beneath the waves. We are reminded every now and then the wonders (and nightmares) of the deep.

New sightings of the great fin squid, a cephalopod with tentacles that can grow up to 26 feet in length, roaming the ocean where sunlight can’t reach, provide one such reminder.

In a study published Wednesday in the open access journal PLOS One, researchers detail five sightings of the mysterious ghostly squid in the Great Australian Bight, off the coast of South Australia. The sightings, the team says, are all of individuals, effectively doubling the number of sightings from the Southern Hemisphere so far. They add to a total of only a dozen sightings over the past 30 years and are the first time the squid has been seen in Australian waters.

To capture the squid with the camera, the team used both towed cameras and remotely operated vehicles at depths between 3,000 and 10,000 feet below the surface. Although the researchers note that it is difficult to fully describe the dweller from the images, they draw some conclusions from their videos.

In particular, the large fins appear to vary from brown to orange and pale pink, and their filaments of arms and tentacles are generally lighter in color. Their measurements differed for each sighting, with a squid about 6 feet long. Two others were some of the smallest large fins ever recorded, with a body length of between 2.5 and 4.5 inches, suggesting they were juveniles. Importantly, no juveniles with long tentacles have been discovered in the past and these sightings have shown that juveniles do indeed have long strands.

Additionally, the team describes a new behavior, never seen before in squid, known as filament winding. One of the videos captured the creature wrapping its arms at the end closest to her body, causing them to be portrayed. It’s not known why the bigfin could do this, but the team suggests it may be the most efficient way to bring its arm strands closer.

A bigfin captured on camera in 2007 in the Gulf of Mexico via cameras distributed by the Shell Oil Company has captured the imagination of the internet for years. Some have called it a Lovecraftian horror, others have compared it to aliens on Independence Day. We’re pretty sure the cephalopods are harmless, but the researchers behind Wednesday’s study didn’t answer our calls and appear to have disappeared.

OK, no, they didn’t.

They plan to conduct further investigations into the Great Australian Bight in the future and note in their study the value of images as a tool for deep sea squid research to find and detail these mysterious wonders lurking in the darkness of our planet.