What you don’t know about the versatile octopus.
May 12, 2014, Vol. 19, No. 33 • By TEMMA EHRENFELD
This volume is full of unexpected revelations, not for the squeamish, starting with the fact that the preferred plural of “octopus” is “octopuses,” not “octopi.” Octopuses, we learn, can lurch onto land and can change color and shape in seconds. After 272 pages in the company of these animals, they no longer seem weird because of their four pairs of arms lined with suction cups. They’re weird because of the ways they contradict our ideas about intelligence.
James Mason and friend in ‘20,000 Leagues Under the Sea’ (1954)
Even Aristotle got it wrong, although octopuses are, of course, plentiful in Greece (where they’re often served in balsamic vinegar). When he wrote that “the octopus is a stupid creature, for it will approach a man’s hand if it be lowered in the water,” he missed that octopuses are more curious than afraid. Like small children, they grab unfamiliar objects, such as underwater cameras, and seem to embrace and fondle them. They gaze through the glass at visitors to aquariums and, like attentive dogs, watch their researchers.
This is all the stranger since, unlike dogs (or dolphins or bees or humans), octopuses are not social. An octopus is a model of self-reliance. Its mother dies as soon as her eggs hatch, and the father soon thereafter. It lives for six months to five years, depending on the species, without bonding to a mate or learning from other octopuses. No man is an island, but every octopus is. Yet octopuses react to us, turning “black with joy” or “white with anger” in response to human actions.
Why might a loner behave in ways that seem social? One argument is that extreme self-reliance requires extreme engagement with the environment. We associate intelligence with dependence in childhood, longevity, and civilization; but in the case of the octopus, it seems that the opposite conditions promote curiosity, problem-solving, speedy learning, and sensitivity.
Roland Anderson, a retired biologist from the Seattle Aquarium, tells author Katherine Harmon Courage that octopuses are the “smartest invertebrate,” and to prove the point, he lists a set of very human traits:
In one experiment, Anderson and his colleagues gave a female giant Pacific octopus named Billy a plastic bottle of herring with a childproof cap. In 55 minutes, she figured out that she needed to push and turn the lid simultaneously and was able to open it; with practice, she could do the trick in five minutes. An octopus can also learn to distinguish vertical from horizontal bars and the letter “V” from “W.” The intelligence of the octopus lies “somewhere in the middle of the birds—maybe not as smart as an African gray parrot,” Courage writes. And birds are an impressive bunch. Many species seem sharper than we once guessed, the author notes, largely because researchers are getting better at reading behavior without imposing a human bias. Still, it’s hard to gauge when imaginative observation is influenced by affection. People who study lobsters, for example, claim that they are smarter than octopuses.
Katherine Harmon Courage reports several tales in which octopuses react to human actions. One researcher describes an octopus pushing up the lid of its tank, apparently trying to get out. The researcher banged on the lid and the animal retreated. The next day, as she sat nearby, the octopus lifted up the lid, brought its funnel to the crack, and squirted a jet of water at her. To test whether an octopus can distinguish between two people, Roland Anderson created a good-cop/bad-cop routine. The bad guy approached a giant Pacific octopus and harassed it with a bristly stick; the good one would come close and feed it. After two weeks, when the bad guy entered the room, the octopus “would shrink back into the corner, it would turn its suckers out to be ready to fight, and it would blow jets of water toward that person,” says Anderson. It also assumed an expression that scientists identify with aggressiveness. When the good cop arrived, the octopus “would come up to the surface or raise its arms up toward the surface,” ready to receive the anticipated food.
Octopuses even exhibit signs of what we call boredom. Trapped in a small, bare tank, they are likelier to throw themselves against its side, to eject ink, or to turn white. When an octopus gets time in a more interesting environment and is then put back in a bare tank, it may eat its own arm.