The Greeks had myths about them. Koreans eat them alive. James Bond tangled with one. They have three hearts and skin that can change color 177 times an hour. They can open childproof jars and help find shipwrecks. They check us out with eyes that are like ours—but better designed. They're playful, curious—and cannibalistic.
But scientists and robotics engineers are only just beginning to come to grips with these enigmatic creatures of the deep. Katherine Harmon Courage tells us about a journey of octopus discovery that took her to Greece, Italy, and New York City.
How did a nice girl like you get involved with an eight-legged cephalopod?
Good question—I'm still trying to figure that out myself! Especially as I grew up in Oklahoma, where I had very little exposure to octopuses.
It's octopuses because we get the word from a Greek root, octopodi. If it were from a Latin root, the plural would be octopi. Scientists also call them octopods.
Next time I play Scrabble I'll remember that. How did you come to write the book?
I was working as an editor at Scientific American, and one day a scientific study arrived on my desk saying octopuses have been observed using tools. And I thought: What could that possibly mean?
So I read the study, which showed that octopuses that live in a very sandy environment without a lot of hiding places, which is what they usually like, were collecting coconut shell halves and carrying them around on the seabed. And whenever they got scared or threatened, they would enclose themselves inside these shells, like temporary shelters. So the researchers said: Well, this shows the collection of material and some kind of planning, which qualifies as tool use. I thought: This is really remarkable—I have to learn a lot more about these guys.
You are obviously hugely enamored of these creatures. What do you love about them?
I just love that they're so different from us but seem to be so complex and sophisticated. They have so much to teach us about evolution, about how their brains work, and I think it's an important exercise for our brains to figure out.
Aristotle famously wrote that "the octopus is a stupid creature." You discovered the opposite. Can you give us some more examples of what you call "octopus smarts"?
They have been shown to be able to solve mazes. They appear to be very curious when they encounter new objects. They explore them very thoroughly. That's why we can get them to do cool things like open bottles. All without instruction.
You encountered many octopuses, mostly in research labs. Tell us about Billey.
Researchers had given octopuses jars to open in the past. As it does with food or prey items, the octopus would pick the jar up and investigate it. Then the researchers thought: Okay, so the octopus can open a regular jar. Let's push the envelope a bit. What if we give it a childproof jar that it has to push down first—and then turn? Billey figured it out in under an hour. But after that, he could open it in a few minutes. Obviously, there is some powerful memory at work there.
One researcher compares their intelligence to that of dogs.
The interesting thing about our interaction with octopuses, if you meet an octopus at an aquarium or a lab, it really engages with you. It will make eye contact, so it appears to be looking at you, checking you out. And that's an interaction a lot of animals don't give us. You don't usually get examined by a snail [laughs], which is an octopus relative, or even a cat. And it's especially curious because we haven't been training octopuses for thousands of years to be our companions or engage with us in that way. Why they have this ability to engage with us is a mystery.
They are one of nature's great loners, aren't they? Like jaguars, they only come together to mate.
Exactly. They're cannibalistic, too, which might explain it! The female will carry the eggs while they're maturing, and as soon as the baby octopuses are hatched, she rolls them out into the water, then goes on her way and dies. So even the babies don't have much contact with their parents.
They have some pretty bizarre mating rituals, don't they?
They do! Almost as wild and varied as octopuses themselves. The male octopus is equipped with a specialized arm, which it uses as its mating ... appendage. Some of them practice what we might call traditional mating tactics. But others, perhaps not wanting to risk getting eaten, will actually detach their arm and hand it over to the female.
The ultimate chivalrous gift.
They can also change their RNA, can't they? Most of us know what DNA is. How does this work?
This was a remarkable discovery a few years ago. We know a lot of animals can do very small amounts of RNA editing, which is a bit like mini-evolution on the go. Our DNA is really in charge of our long-term structure, what color our eyes are, things like that. RNA can change some short-term physiological functions. But the amount octopuses can change their RNA is really unique in the animal kingdom. They even seem to be able to change the speed of their nerve signaling so that they can continue to survive in extreme environments, like very cold waters.
They're being used in robotic research, aren't they?
Yes. The octopus has an almost infinite range of motion in all eight of its arms, so to be able to try to build a robot that can even start to replicate those abilities is the ultimate engineering challenge. One of the places I went was a research lab in Livorno, Italy, near Pisa. In 2010, they started to build the first octopus robotic arm that could move around and grab objects. It's very interesting technology and one that will have many applications one day. But it was also a bit creepy—as I got to feel the robotic octopus arm wrapped around my finger!
The squeamish should probably look away now. But as well as studying them, you ate octopus all over the world. Tell us about Live Korean-Style Octopus.
That was in Queens, in New York City, in a wonderful Korean neighborhood. The restaurant had a huge tank of octopuses by the kitchen, and they would yank the octopus out of the water and quickly chop off its arms and cut them into little pieces, put them on a plate and serve them with various dipping sauces and garnishes. [Groans] I hate to say this, but it was really quite tasty. And it was a fascinating experience from the neurological perspective because the octopus arm continues to move and even respond to stimuli after it has been severed from the brain. If you touched them with a chopstick, they would try and grab on.
In your epilogue, you mention that 50,000 tons of octopus is harvested from the sea each year. Is that sustainable?
That's a really important question right now. Especially in the U.S., where octopus has become a much more popular menu item. And we really don't know how many octopuses there are. They're very hard to study. Unlike cod or other kinds of fish, you can't tag them or put a tracker on because they'll just take it off with their arms or slink out of a collar. The good news is that they seem to be a fairly robust species. They've been around for millions of years—they've survived extinctions that killed the dinosaurs off—so they appear to be primed to adapt quickly to new environments and new pressures.
How has your work on octopuses changed your perspective on your own life?
It has really opened my eyes to the possibilities of evolution. The way they interact with us, and look at us, really captures our imaginations. Their eyes are remarkably similar to our own, physiologically ... a bit better than ours, as their optic nerve is on the outside, so they don't have a blind spot as we do. Our common ancestor was a sightless marine worm, so it's fascinating to think that from this ancestor so many different types of vision and eye have evolved—and how our eye and the octopus's eye are so similar.
This interview has been edited and condensed.