Octopus, the Mensa mollusk

The author pets Octavia.Tia Strombeck

Everyone wanted to pet Octavia.

And no wonder. She was beautiful, graceful, and affectionate. The fact that she was boneless, slimy, and living in painfully cold, 47-degree water deterred none of us.

What thrilled us — me, New England Aquarium volunteer Wilson Menashi, and four visitors from the environmental radio show “Living on Earth” — was the surprising fact that Octavia, who clearly wanted to be petted, was a giant Pacific octopus.

When her keeper, Bill Murphy, opened the top of her exhibit, Octavia recognized Menashi and me immediately; we’d been working with her for several weeks. Turning red with excitement, she flowed over toward us from the far side of her tank. When we put our hands in the water, her arms rose to meet ours, embracing us with dozens of her strong, sensitive, white suckers. Occasionally Wilson handed her a fish from the plastic bucket perched on the edge of her tank.

Soon the “Living on Earth” crew joined in. People were tentative at first. In movies and stories, octopuses are portrayed as monsters, and the giant Pacific is the largest and strongest of them all. A single sucker on a large male can lift 30 pounds, and the animal has 1,600 of them. Octavia’s were strong enough to leave hickies on our arms. But she was so curious and friendly that no one could resist the chance to touch her skin, which was soft as custard. We stroked her much as we would a dog, enchanted with the spectacle of her color-changing skin, the sensation of her suckers, the acrobatics of her many arms.

Then, as Menashi reached for another capelin to feed her, we realized the bucket of fish was gone.

While no fewer than six people were watching, and three of us had our arms in her tank, Octavia had stolen the bucket right out from under us.

“Octopuses are phenomenally smart,” Menashi says. And he should know: He has worked with them for 20 years, and is expert in keeping these intelligent invertebrates occupied. Otherwise, they become bored. Aquariums design elaborate escape-proof lids for their octopus tanks, and still they are often thwarted. Octopuses not infrequently slip out of their exhibits and turn up in other tanks to eat the inhabitants.

Many aquariums give their octopuses Legos to dismantle, jars with lids to unscrew, and Mr. Potato Head to play with. Menashi, a retired inventor, designed a series of nesting Plexiglas cubes, each with a different lock, which Boston’s octopuses quickly learned to open to get at a tasty crab inside. And just this spring, New Zealand Sea Life aquarists teamed up with Sony engineers to teach a female octopus named Rambo to press the red shutter button on a waterproof camera to take photos of visitors, which the aquarium sells for $2 each to benefit its conservation programs. Rambo learned in three attempts.

Intelligence so like our own may seem surprising in a creature so unlike us. “Short of Martians showing up and offering themselves up to science,” says neuroscientist Cliff Ragsdale of the University of Chicago, octopuses and their kin “are the only example outside of vertebrates of how to build a complex, clever brain.”

The octopus brain looks very different from a human’s. Our brain sits like a nut in the shell of our skull. Octopuses lack bones of any kind and their brains wrap around the throat. Our brain is organized into four lobes. Theirs has 50 to 75 lobes, depending on how you count them. Most of our nerve cells are in our brain. Three-fifths of an octopus’s nerve cells are in the arms.

The wonder is that octopuses and humans may think, in many ways, alike. We both enjoy learning new things, solving puzzles, meeting new friends. And possibly, we both enjoy a good joke: when Octavia stole the bucket, she didn’t eat any of the fish in it. When we finally realized she had taken it, we saw she had wrapped it in the webbing between her arms, as if she was purposely hiding it from us.

As long ago as the turn of the third century, Roman naturalist Claudius Aelianus wrote of the octopus that “mischief and craft are plainly seen to be the characteristics of this creature.” Perhaps Octavia especially enjoyed her caper for having outwitted us humans.

“So if an octopus is this smart,” one of our guests asked her keeper, “what other animals are out there that could be this smart — that we don’t think of as being sentient and having personality and memories and all these things?”

An excellent question indeed.