Octopuses are one of the most fascinating creatures in the sea.
They’re known to be highly intelligent and playful creatures, but where do these smarts stem from?
An octopus has nine brains: one central brain, and eight smaller brains located in each of its arms. The central brain is shaped like a donut and wraps around the esophagus, and it sends commands to the other brains. The smaller brains give each arm the ability to individually move, touch, and taste its environment.
Continue reading to learn about octopuses’ nine brains and evidence of their incredible intelligence.
Octopuses And Their Nine Brains
Octopuses and their relatives, squid and cuttlefish, stand out from the majority of invertebrates because of the way they’ve evolved.
Their nervous systems are quite a bit larger than most invertebrates, and they have increased cognitive complexity.
These invertebrates have multiple features in common with the brains of vertebrates, although their brain anatomy is different.
Octopuses have varying versions of sleep, types of short-term and long-term memory, and the ability to recognize individuals and explore through play.
Take a look at the video below for a fun overview of octopuses’ brains and intelligence.
One Central Brain
Octopuses have nine brains in total, and the larger central brain has control over the octopus’s nervous system.
This brain is located in its head and shaped like a donut. It wraps around the esophagus.
Eight Smaller Brains
Meanwhile, each of the octopus’s eight arms contains a small brain or cluster of nerve cells that controls its movement. These smaller brains enable each arm to move, touch, and taste without direction from the central brain.
Because of these nine brains, an octopus’s arms can work together, but also independently of each other.
Thanks to their multiple brains, octopuses are capable of using their arms to complete tasks very quickly and effectively.
Octopuses’ central brains have wrinkles and folds, which develop through a process called gyrification.
This process usually takes place in the highly-evolved and complex brains of vertebrates, but has been observed in 20 octopus species as well.
How Octopuses’ Brains Work Together
The central brain sends commands to the other eight brains, such as “look for food.”
In response, each of the octopus’s arms moves around, contracting and relaxing their muscles, feeling their surroundings, and tasting food.
Meanwhile, the central brain focuses on watching out for predators.
Once one of the octopus’s arms has located food, that information is sent back to the central brain, which can then decide what type of action to take.
How Intelligent Are Octopuses?
To estimate an animal’s level of intelligence, scientists often look at the size of an animal’s brain in relation to its body.
Although this isn’t a perfect measure of intelligence, smarter animals typically have a higher ratio of brain to body.
Of all invertebrates, octopuses have the largest brain-to-body ratio. In fact, octopuses’ brains are larger than many vertebrates’ brains (aside from mammals).
Octopuses have about the same number of neurons as dogs.
Octopus vulgaris, also known as the common octopus, has approximately 500 million neurons, with about 66% of them located in its arms and the rest in its central brain.
Aside from the size of their brains and the number of neurons they have, octopuses show their intelligence through their various abilities.
Navigate Complex Tasks
Octopuses can complete complex tasks and solve mazes to obtain food.
They’re highly adept at wiggling their way in and out of differently-shaped containers.
Employ Advanced Hunting Tactics
Certain types of octopuses have fascinating hunting tactics.
For example, the Pacific striped octopus creeps up to its prey, taps it on the shoulder, and catches the prey with its other seven arms when it leaps away.
In addition, octopuses employ different types of hunting tactics for each of the types of prey they eat, including fish, clams, and crabs.
Octopuses are also known to use tools, which is a rare characteristic in the animal kingdom and an indicator of an animal’s ability to learn.
In their natural habitats, octopuses have been seen to use stones as shields to protect the entrance of their dens.
They also use tools to obtain food in lab environments.
The common blanket octopus sometimes carries Portuguese man o’ war tentacles to use as a weapon.
Although the common blanket octopus is immune to the potent venom of these tentacles, it can use them on both its predators and its prey.
An octopus’s brain has large optic lobes, which are the parts of the brain that have to do with vision. This indicates that an octopus’s vision is extremely important to its lifestyle.
Octopuses can recognize individuals, including those of different species. They can even recognize human faces.
One article discussed an octopus that seemed to dislike one of the staff members at the university where it lived in captivity.
Every time this particular staff member walked by the octopus’s tank, it squirted water at her.
The mimic octopus has the ability to complete transformations into different types of animal species to trick its predators. It can change its appearance to look like a flounder, tunicate, lionfish, sea snake, and other creatures.
This octopus chooses the appearance it will take on based on the predator at hand.
Scientists observed a mimic octopus that transformed to look like a banded sea snake when a damselfish started to attack it. A banded sea snake is one of damselfishes’ known predators.
Octopuses have nine brains in total. One brain is the central or main brain, and it’s shaped like a donut and located in the octopus’s head. The central brain sends commands to the other eight brains, each of which is located in one of the octopus’s eight arms.
The octopus’s smaller brains provide each arm with the capabilities of moving, touching, and tasting the surrounding environment on their own.
These animals are highly intelligent, with the ability to navigate complex tasks, employ advanced hunting tactics, utilize tools, recognize individuals of other species, and more.