Octopuses have been captured on camera using coconut shells as disguises and for protection, astonishing the Australian scientists who made the discovery.
Footage shot off Indonesia shows an octopus crawling along the ocean floor with two coconut shell halves suctioned to its underside, behaviour which biologists describe as "bizarre".
The octopus then reassembles the coconut and hides inside it, confirming the species as a tool-carrying animal, according to National Geographic.
Researchers from Melbourne's Museum Victoria filmed 20 veined octopuses carrying the coconut shells that were nearly twice as big as their 8cm bodies.
"We were blown away," biologist Mark Norman said.
"It was hard not to laugh underwater and flood your [scuba] mask."
The discovery comes from a 10-year study filming octopuses off the coast of Sulawesi and Bali.
Tool use by animals is seen as a sign of mental sophistication, with dolphins and chimpanzees also using tools.
Octopuses are considered to be among the smartest animals on Earth.
aap 15 Dec 2009