Wannabe Crabs, Ctd

by Chris Bodenner

After watching this video we posted of coconut-carrying octopuses, a reader points to an interesting article that Slate published last year:

YouTube is loaded with evidence of what some might call octopus intelligence. One does an uncanny impression of a flounder. Another mimics coral before darting away from a pushy camera. A third slips its arms around a jar, unscrews it, and dines on the crab inside. Scientific journals publish research papers on octopus learning, octopus personality, octopus memory. Now the octopus has even made it into the pages of the journal Consciousness and Cognition (along with its fellow cephalopods the squid and the cuttlefish). The title: "Cephalopod consciousness: behavioral evidence."

The earliest cephalopods, which lived about a half-billion years ago, had shells. Over the next 250 million years, they evolved into giant predators. They shot bursts of water out of siphons to swim—a prehistoric form of jet propulsion.* But their glory was cut short by fish with jaws—our ancestors. Fish could swim faster by bending their bodies than cephalopods could move by jetting. Today, only a single shelled cephalopod survives—the nautilus, which spends most of its life lurking deep underwater.

The other living cephalopods lost their shells. While they gave up a defense against predators, they were free to evolve new skills. Squids became fast swimmers. Octopuses instead moved to the sea floor, where they could use their shell-free bodies to explore cracks and crevices for prey. But in order to survive in this new niche, they had to become fast learners.