Marine researcher Lauren De Vos studies biodiversity around South Africa's False Bay, where she uses food-laden cameras to record sea life in action. Known as baited remote underwater video, or BRUV, this non-extractive method "offers a low environmental impact way of understanding changes in fish numbers and diversity over time," she explains in a blog post for the Save our Seas Foundation.

But while fish may be content to nibble at these baited cameras, some marine animals are a little more ambitious. The video below shows an octopus wrapping its tentacles around one of De Vos' BRUV canisters, untying three cable knots (without even looking) and stealing the whole thing. As if that isn't impressive enough, the inventive invertebrate does it all while using one arm to restrain a hungry catshark. Check out the video evidence, which De Vos aptly set to bluegrass music:

Octopuses are widely considered the world's smartest spineless animals, performing feats of intelligence — from building makeshift coconut shelters to remembering other octopuses — that are beyond most invertebrates. In fact, while many other mollusk brains contain fewer than 20,000 neurons, the common octopus has about 130 million. And as naturalist Sy Montgomery recently reported in Orion magazine, that's not even the half of it: Three-fifths of an octopus's neurons are in its arms, not its brain.

"It is as if each arm has a mind of its own," a professor of biological philosophy tells Montgomery. "Meeting an octopus is like meeting an intelligent alien."

For more information about De Vos' research, check out her BRUV blog.

Related octopus stories on MNN:

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

Clever octopus tames shark, unties knots
An underwater camera captures an octopus untying knots to steal a canister of food — all while restraining a small shark with one of its tentacles.