All rights reserved. Other octopus species live in deep, dark waters, rising from below at dawn and dusk to search for food. Crabs , shrimps , and lobsters rank among their favorite foods, though some can attack larger prey, like sharks. Octopuses typically drop down on their prey from above and, using powerful suctions that line their arms, pull the animal into their mouth. The octopus performs its famous backward swim by blasting water through a muscular tube on the body called a siphon.
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My love affair with octopuses began when I was 9. It was clambering over rocks in the shallows, changing color as it went.
Cousteau and his team were the first to spend a lot of time—many hours at a stretch—in the water observing and filming wild octopuses and getting to know different individuals by visiting them regularly. Before long, some of the animals would come out to greet the divers, even climbing onto them and going for a ride. Others were shy, and would stay in their holes. Some appeared to develop preferences for particular humans.
Sure enough, an octopus came and helped itself to the lot. Another octopus opened a jar containing food, while a third seemed disturbed by its reflection when shown a mirror. Yet, taken together, they capture three aspects of octopuses—some species of them, at least—that strike anyone who spends time in the water with them. First, different individuals have different temperaments. Some are shy, some are bold; some are inquisitive, some aggressive.
Because of this individuality, people who hang out with them, whether in the sea, at a public aquarium, or in the laboratory, tend to give them names—an honor normally reserved for mammals such as dolphins and chimpanzees.
Cousteau spoke of an octopus called Octopissimus; one scientific paper I read referred to Albert, Bertram, and Charles. Second, some octopuses will engage with you. They might reach out an arm and touch your hand. They will investigate an object you present to them, giving every impression of thinking about it as they do so. All the while, they will appear to watch you with their large, mobile eyes. Again, these are behaviors we associate with dolphins and dogs—but not with, say, fish, let alone animals such as sea urchins or clams.
Third, octopuses often behave in surprising ways. Although Albert and Bertram were prepared to pull levers to receive pieces of fish, Charles destroyed the experimental equipment—he pulled it apart with his arms—and repeatedly squirted the experimenter with water. On a recent diving trip, my partner and I came across a little octopus sitting in the sand, two of its arms holding a large half clamshell over its head like a roof.
For a while, we looked at it, and it looked at us. Then it shifted. It must have been reaching down with its other arms, because suddenly, like a small animated bulldozer, it tossed up a heap of sand. It did this several times, watching us closely and giving us the sense that, though it was interested in checking us out, it was also ready, if necessary, to pull the shell down like a lid and disappear into the seafloor.
The animals also frequently change their skin color and texture—which, to creatures such as ourselves, fine-tuned to watch faces for frowns and smiles, blushes and blanches, gives the appearance of emotional expressiveness.
But that mind—if mind it is—has evolved along a route entirely different from the one that led to our own. The most-recent common ancestors of humans and octopuses lived about million years ago, early in the evolution of animal life. Although much about our joint ancestors is obscure, they were probably small wormlike creatures that lived in the sea. This makes octopuses very different from other animals we suspect of sentience, such as dolphins and dogs, parrots and crows, which are much more closely related to us.
This is probably the closest we will come to meeting an intelligent alien. Godfrey-Smith is a scuba-diving philosopher; his specialties are philosophy of biology and philosophy of mind. While out diving some years ago, he began encountering octopuses and cuttlefish, became intrigued, and started studying them.
The result is Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness, a terrific mix of Cousteau-esque encounters with the animals in the wild including a giant cuttlefish he calls Kandinsky , wide-ranging scientific discussion, and philosophical analysis. Beautifully written, thought-provoking, and bold, this book is the latest, and most closely argued, salvo in the debate over whether octopuses and other cephalopods are intelligent, sentient beings.
M ind, intelligence, sentience , consciousness —these are difficult, slippery terms, especially when applied to nonhuman animals. Several octopus researchers have told me that intelligence is a word they shy away from, either because of the SAT-like connotations, or because they feel that evidence for it is lacking, or because they think focusing on intelligence is narcissistic and fails to capture other important aspects of the wonder of these animals.
Consciousness is even more contentious. Light-sensing mechanisms run the gamut from molecules to eyespots to a huge variety of more complicated eyes. Nervous systems, too, show different levels of complexity; some are small and simple, while others are larger and more intricate. Indeed, as Godfrey-Smith reminds us, William James, the great 19th-century philosopher and one of the founders of psychology, argued that we should avoid assuming that human consciousness irrupted, fully formed, into the universe, and should seek simpler precursors.
Taking this to its logical conclusion, Godfrey-Smith starts his quest for the origin of minds around the dawn of animal life, when nervous systems were first evolving into being. In many ways, they are indeed profoundly alien. The animals are mollusks, and thus more closely related to other mollusks, such as clams and snails, than they are to any mammal. Most famously, they have eight arms, each lined with scores of suckers capable of grasping and tasting.
Octopuses lack bones or an external shell though they have a piece of cartilage that protects the brain. As a result, their bodies are soft, flexible, and stretchy—properties that allow them to vanish through tiny gaps. A small octopus can easily get inside an empty beer bottle. And in some species at least, the animals have an astonishing capacity for camouflage, instantly changing color, texture, and posture so as to blend in with lumps of coral on a reef or the blankness of the sand. This helps them hide from the many animals that fancy having octopus for lunch.
This makes them, like many marine animals, hard to study in the wild. Just to find out what octopuses do all day takes tag teams of observers spending hours snorkeling or diving.
Only a handful of groups have ever attempted such work. And octopuses have a reputation for being difficult to keep in the laboratory—they are sensitive to water quality, tricky to look after, and well-known escape artists.
Their eyes are remarkably like human eyes, an example of evolution converging on roughly the same solution from two wildly different starting points. Like us, octopuses are dexterous, and can reach out and manipulate objects in the world.
They display all those inquisitive, friendly behaviors reminiscent of dolphins and dogs. Most telling of all, octopuses, along with cuttlefish and squid, have far larger, more complex nervous systems than any of their molluscan relations—or indeed, than any other invertebrates—do.
The California sea slug also a mollusk has about 18, neurons, and honeybees, the invertebrate runners-up for neuron count, have roughly 1 million. The common octopus, Octopus vulgaris , has about million neurons.
This is more than five times the number in a hamster, and approaches the number in the common marmoset, a kind of monkey. Humans have about 86 billion. Going just on the basis of neuron count, you might think octopuses were a kind of mammal. Which raises several questions. What forces led octopuses to evolve such large nervous systems?
Does having a large nervous system necessarily mean octopuses are intelligent, even conscious? And if they are, is their experience of consciousness something akin to our own, or is it—reflecting, perhaps, their distributed nervous system—entirely different? Drawing on the work of other researchers, from primatologists to fellow octopologists and philosophers, Godfrey-Smith suggests two reasons for the large nervous system of the octopus. One has to do with its body. For an animal like a cat or a human, details of the skeleton dictate many of the motions the animal can make.
An octopus, having no skeleton, has no such constraint. It can, and frequently does, roll up some of its arms; or it can choose to make one or several of them stiff, creating an elbow. Surely the animal needs a huge number of neurons merely to be well coordinated when roaming about the reef.
At the same time, octopuses are versatile predators, eating a wide variety of food, from lobsters and shrimps to clams and fish.
Octopuses that live in tide pools will occasionally leap out of the water to catch passing crabs; some even prey on incautious birds, grabbing them by the legs, pulling them underwater, and drowning them. Animals that evolve to tackle diverse kinds of food may tend to evolve larger brains than animals that always handle food in the same way think of a frog catching insects. But are they clever?
While pigeons will spend hours pecking keys to get food rewards, octopuses are notoriously feisty. Charles is by no means alone in electing to squirt the experimenter instead of following the protocol.
As for assessing animal consciousness, that at first seems impossible. But one angle of attack is to work from the situation in humans. Over the past 30 years, a growing body of results has shown that conscious awareness represents just a fraction of what the human brain is registering.
At the same time, scientists are identifying the type of tasks that do require consciousness. In particular: Consciousness seems essential for learning new skills—such as finding an alternative way home or opening a coconut.
Like humans, octopuses learn new skills. In some species, individuals inhabit a den for only a week or so before moving on, so they are constantly learning routes through new environments. Similarly, the first time an octopus tackles a clam, say, it has to figure out how to open it—can it pull it apart, or would it be more effective to drill a hole?
If consciousness is necessary for such tasks, then perhaps the octopus does have an awareness that in some ways resembles our own. If evolution can produce similar eyes through different routes, why not similar minds?
Or perhaps, in wishing to find these animals like ourselves, what we are really revealing is our deep desire not to be alone. We want to hear what you think about this article.
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Olivia Judson is an evolutionary biologist and a writer.
On Thursday morning, workers filing into the Santa Monica Pier Aquarium in California were surprised to find gallons liters of seawater soaking into their spanking new, ecologically sensitive flooring. It turns out that a curious two-spotted octopus had disassembled a water recycling valve and directed a tube to spew out of the tank for about 10 hours, according to the Los Angeles Times. But calling the eight-armed cousin of your garden snail "smart" seems a bit of a stretch. In fact, the animals are part of an elite group of slimy mollusks known as cephalopods that range from giant squid to the shelled nautilus and all have remarkably large " brains "—at least for creatures sans backbones.
Are octopuses smart?
Octopuses are ocean creatures that are most famous for having eight arms and bulbous heads. Some other fun facts: They have three hearts and blue blood; they squirt ink to deter predators; and being boneless, they can squeeze into or out of tight spaces. They are quite intelligent and have been observed using tools. The order Octopoda includes species, according to the World Animal Foundation. The Most Mysterious Creature in the Sea. Some people call their appendages tentacles, but that is incorrect; they are arms.
What the Octopus Knows
My love affair with octopuses began when I was 9. It was clambering over rocks in the shallows, changing color as it went. Cousteau and his team were the first to spend a lot of time—many hours at a stretch—in the water observing and filming wild octopuses and getting to know different individuals by visiting them regularly. Before long, some of the animals would come out to greet the divers, even climbing onto them and going for a ride. Others were shy, and would stay in their holes.