Friday, March 25, 2005

Walking Calamari 

The marine bio story for today: It's been discovered that two species of octopuses walk on two legs.

Octopuses occasionally stroll around on two arms, UC Berkeley biologists report

Two species of tropical octopus have learned a neat trick to avoid predators - they lift up six of their arms and walk backward on the other two.

This first report of bipedal behavior in octopuses, written by University of California, Berkeley, researchers, will be published in the March 25 issue of Science.

When walking, these octopuses use the outer halves of their two back arms like tank treads, alternately laying down a sucker edge and rolling it along the ground. In Indonesia, for example, the coconut octopus looks like a coconut tiptoeing along the ocean bottom, six of its arms wrapped tightly around its body.



Besides the "Gee, that's pretty neat" factor, this behavior could revolutionize the field of robotics:


"A lot of behavior is built into the ganglia (nerves) of each octopus arm, so that seemingly complex behavior is really simple," (UC Berkeley Professor Robert) Full added. Similar controls could make a soft robotic arm a lot easier to control than it would seem, and make it feasible to build an octopus robot that walks.


A soft robot would conceivably have a greater range of motion than today's stiff robots. But how would they fare on Battlebots?

Another neat part of this story is the discovery was made by a grad student.


(UC Berkeley graduate student Crissy) Huffard first noticed the coconut octopus, Octopus marginatus, dancing along the sand in 2000, while helping a film crew obtain octopus footage off the island of Sulawesi in Indonesia. The octopus, with a head about two inches long, lives on the sandy bottom in water some 20 to 30 meters (60 to 100 feet) deep, among lots of sunken coconuts, and even hides out in the shells of coconuts, drawing two halves around it to hide.

Its weird walking behavior, no doubt noticed by numerous other divers, has apparently never been reported in the scientific literature, she said.


Not all neato scientific discoveries are made by some big-named tenured professor. You could be doing research, notice something, and the next thing you know you're in the news. Cool.

When I was taking Aquatic Bio at UCSB, I heard quite a few anecdotes about just how smart octopuses were. My all time favorite was the story of the missing fish. In a lab, there were several tanks which included fish tanks and octopus tanks. The lab personnel began to notice their fish were mysteriously disappearing. They set up a camera, and discovered why, the octopus would lift up the lid of the octopus tank, crawl across the table to the fish tank, get into the fish tank, eat the fish, and then return to the octopus tank. A pretty neat trick for an invertebrate.

Another of my favorite tricks is when an octopus ends up on my plate in the form of calamari. Yum!

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