The new videos also show the squids coiling their filaments, a behavior that has never been observed before.

Though little is known about them, researchers believe these cephalopods are found across the globe, from the Pacific to the Atlantic to the Indian Ocean. Their appearance off southern Australia supports this notion of the squids’ marine cosmopolitanism. With the new paper, the number of reports from the Southern Hemisphere has more than doubled.

In a 2001 Science paper, Vecchione and his colleagues marshaled evidence from eight sightings of bigfins. Vecchione is often called in to identify the hitherto unidentified swimming organisms. His first encounter with this particular one came after a Texas woman sent him grainy video of an enormous squid. The marine zoologist remembered jumping out of his chair: he’d expected to see the giant squid,  but what he found was different from anything he’d ever seen before.

“That such a substantial animal is common in the world’s largest ecosystem, yet has not previously been captured or observed, is an indication of how little is known about life in the deep ocean,” the 2001 paper noted.

This didn’t change in the ensuing decade. A 2010 paper termed the lack of exploration of Earth’s largest and most vibrant habitats, the expanse below 200 meters (660 feet) of the ocean’s surface, as “biodiversity’s big wet secret.

In recent years, the specter of deep-sea mining has loomed large over the world’s oceans. Companies and countries keen to meet rising demand are eyeing mineral deposits in these remote and still pristine corners of the world. It has made research on these ecosystems a matter of even greater urgency.

A Magnapinna squid swimming horizontally with rapid fin flapping in water affected by ROV thruster turbulence. Image Courtesy of Deborah Osterhage/Great Australian Bight Deepwater Marine Program.

In the Great Australian Bight, two massive research programs have been undertaken in the past 10 years. The surveys that captured the bigfins on video were conducted as part of the Great Australian Bight Deepwater Marine Program led by Australia’s premier science agency, CSIRO, and sponsored by Chevron Australia. The other initiative was a collaboration between CSIRO and  U.K.-headquartered oil giant BP.

These forays uncovered 277 newly described species from the region. Though Osterhage’s team did not set out to look for the squids specifically, they were on “our wish-list of organisms we did want to see,” she said.

Scientists like Vecchione hope their work will spark further research on the enigmatic animals. However, he said he worries that despite the species’ remoteness from humans, they might still be vulnerable to human activities, especially those that generate carbon emissions.

“Probably for all of the animals in this zone, the biggest threat would be climate change,” he said. “You wouldn’t think that the deep ocean would be affected by that, but there’s increasing evidence that it is.” He added that these impacts manifested not just in temperature changes but also the availability of food.


Osterhage, D., MacIntosh, H., Althaus, F., & Ross, A. (2020). Multiple observations of Bigfin Squid (Magnapinna sp.) in the Great Australian Bight reveal distribution patterns, morphological characteristics, and rarely seen behaviour. PLOS ONE, 15(11). doi:10.1371/ journal.pone.0241066

Vecchione, M., Young, R. E., Guerra, A., Lindsay, D. J., Clague, D. A., Bernhard, J. M., … Segonzac, M. (2001). Worldwide observations of remarkable deep-sea squids. Science, 294(5551). doi:10.1126/science.294.5551.2505

Malavika Vyawahare is a staff writer for Mongabay. Find her on Twitter: @MalavikaVy

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