An Octopus Totes a Coconut Fortress for Trouble It Hasn't Met

A small octopus tucks two coconut-shell halves under its body, wraps its arms around the edges and walks across the seafloor on stiffened limbs. It looks like a very slow, very committed stilt-walker hauling garbage. That's because it is. The shells offer zero protection during the trip. The octopus carries them anyway.

The veined octopus (Amphioctopus marginatus) lives in sandy, exposed habitats with little natural cover, and its soft body makes it dangerously vulnerable if spotted. So it improvised. It collects hollow coconut husks discarded by coastal settlements, tucks them under its body and walks on tip-tentacles, covering hikes of up to 20 meters (66 feet) across open seafloor. Sometimes it manages both halves at once, one nested inside the other. When danger arrives, it quickly assembles the halves into a hardened sphere and holds them shut with its suckers. When it's ready to move again, it dismantles the whole thing and walks away with it.

Researchers Julian Finn, Tom Tregenza and Mark Norman spent more than 500 diver-hours over 10 years documenting the behavior in Indonesian waters off Sulawesi and Bali. They argue it qualifies as bona fide tool use. Many invertebrates shelter in shells, and hermit crabs do it permanently, but the veined octopus accepts a more exposed and awkward situation now because the shells become useful later. That anticipatory logic is what separates this from simply borrowing cover.

The cognitive machinery producing this behavior runs on hardware that is not vertebrate, not centralized and arrived at this solution independently of every other tool-using animal on the list.

Evolution apparently doesn't care whether an ingenious solution looks dignified while you're carrying it home.

Read the full story at National Geographic, December 14, 2009

Hot Take: Monty Python gave us a man banging coconut halves together to fake a horse. The octopus looked at the same raw materials and built a mobile fortress. Advantage: octopus.