Octopuses are known to be some of the most intelligent animals on earth, alongside chimps, dolphins, orcas, and sea otters.
They are part of the cephalopod family alongside cuttlefish and squid and have an incredibly large brain-to-body ratio.
Today, we’re going to take a closer look at octopuses’ brains and answer a question that often has people intrigued when it comes to these fascinating animals.
How many brains does an octopus have?
Octopuses have nine brains, one in their head and one mini-brain in each of their eight arms. This allows octopuses to complete tasks with their arms more quickly and effectively.
How Many Brains Does An Octopus Really Have?
Octopuses have nine brains in total, with one centralized brain controlling the nervous system and then there is a small brain for each of their arms.
This allows each arm to operate somewhat independently. The central brain tells the in what direction and how fast to move, but the instructions on how to reach are embedded in each arm.
Octopus arms can search autonomously when they’re searching, which makes them perfect for searching around for food on the seafloor.
Why Do Octopuses Have Nine Brains?
Octopuses have a decentralized nervous system with the majority of their neurons residing in their arms.
These neurons help the arms to independently taste, touch and control basic motions without consulting the larger, central brain in its head.
This is incredibly beneficial for searching the ocean for food, allowing the arms to operate independently but also contributing to the same goal.
Neurons are like messengers that send signals from the brain to various parts of the octopus’s body.
In total across the octopus’s whole body, they have around 500 million neurons, which may sound like a lot but we humans have upwards of 100 billion.
However, octopuses have roughly the same number of neurons as dogs, which makes scientists believe that they are about as intelligent.
Approximately 180 million of the 500 million neurons are located in the octopuses’ central brain, and roughly 40 million are located in the octopus’s ganglia of each of its arms.
This means that around two-thirds of an octopus’s neurons are found in its arms, which is just one of the fascinating facts about its nervous systems.
The neurons at the base of each arm connect to the suckers that spread across it, with each arm having roughly 250 suckers.
Each of these suckers may have around 10,000 neurons which the animal uses to detect physical sensations through touch.
The Benefits Of Having Multiple Brains
Having multiple brains is incredibly beneficial to octopuses in a number of ways. Distinct ganglia controlling each individual tentacle make up for the creature’s fluid body and lack of a skeletal system.
Having multiple mini-brains also takes some of the performance power away from the larger centralized brain, allowing this brain to focus on more important tasks.
Below I’ve listed some of the top benefits of the octopuses’ nine brains:
- Octopuses can react faster to threats and predators as they do not need to consult the centralized brain first.
- They are able to regenerate their arms if one is severed, which also means they can generate a new ganglion.
- Octopuses are able to fine-tune the movement of each of their arms, allowing them to pass work off to the ganglia such as searching for food.
- More processing power for the central brain to use, increasing their overall intelligence and giving them more bandwidth.
- Allowing each individual tentacle to smell, touch and taste without them needing to consume anything or waste time eating.
The Octopus Nervous System
The nervous system of Octopuses is highly complex, but it’s important to understand when looking at why these animals are so intelligent and what this has to do with having multiple brains.
Whilst the octopuses’ anatomy is vastly different from that of a vertebrate, they do have some cognitive abilities in common.
For example, they are believed to poses both long and short-term memory, which helps them plan ahead as they draw upon experiences from the past, future, and present.
Not only that, but they also engage in sleep, just as we humans do, are known to explore objects through play, and can even recognize individual human faces.
The relative size of octopuses’ brains is within the range of that of vertebrates, but not quite as high as the relative size of mammals’ brains to their bodies.
Due to the design of the octopuses’ nervous system and the relative size of their brain, they’re famous for displaying intelligence in many ways.
Some examples of octopus intelligence and what they are known for are below:
- Using empty coconut shells as a form of protection from predators.
- Instead of hunting prey, sneaking into crab pots, and stealing the catch from fishermen.
- Unscrew jar lids to get at the food that is inside.
- Solve mazes and complete tricky tasks for food rewards.
- Arm themselves with jellyfish stingers as a form of protection.
So, how many brains does an octopus have? Nine, one central brain and eight small mini-brains in each of their eight arms.
These mini-brains allow the tentacles to act independently without needing to communicate with the brain.
This has numerous benefits, one of which is to help in searching the ocean for food. Each arm is also able to smell, taste and touch thanks to having many neurons attached to it.
It also allows the octopus to react quickly to threats and allows them to fine-tune the movement of each of its arms.
These animals are highly complex, as is their unique nervous system. Upon closer inspection of the octopus’s brains, it’s easy to see why these are some of the most intelligent animals on earth.
Hopefully, you’ve enjoyed this post today and have learned a thing or two about the octopus and why they have nine brains instead of one.
Thanks for taking the time to read this post and feel free to stick around to learn more about octopuses and other marine life.
Hi, I’m George – the founder of MarinePatch. I created this blog as marine wildlife has been my passion for many years. I’ve spent over a decade in the marine wildlife industry and spent years out in the field conducting research. In today’s modern world, an online blog is the best place for me to share my findings and reach as many people as possible to help educate and inspire others. Enjoy your time here and you’re welcome back anytime!