An Alien in Our Sea: A look at the intelligence of an octopus

Image credit: Elisabetta Lando

In 2016, one of my favourite sci-fi films Arrival was released, and – mild spoiler alert – it presented us with an alien species named the heptapods, who challenged human perception of the universe and life. Had these species originated instead from Earth, I wouldn’t blame you for assuming them to be related to the similarly unearthly-looking octopus. A mollusc-looking seven limbed creature, with a long protruding body, and no external shell; the heptapod is clearly modelled on a cephalopod.

Life in Another Phylum

Why the film’s vision for this species is so obviously octopian is open to interpretation, but centuries of art and literature have certainly demonstrated that the octopus has always inspired our collective imaginations; and it’s definitely not the first time it has been associated with alien life. 

In terms of separation down the evolutionary timeline, the octopus is about as far away from humans as an animal can get.

The octopus belongs to a class of marine species called cephalopods within the Mollusca phylum, along with the likes of cuttlefish and squid. The name cephalopod indicates a species that has tentacles attached to a distinct head, Cephalo coming from the Greek for ‘head’ and pod from ‘foot’

In terms of separation down the evolutionary timeline, the octopus is about as far away from humans as an animal can get. The last common ancestor of us and octopuses is a flatworm that trawled the sea floor 750 million years ago. This is the most recent creature that we both have a direct line of descent from – it represents the point at which we diverged down separate evolutionary pathways. To illustrate just how early this was, this was 80 million years before any animal showed bilateral symmetry – the familiar body plan with a defined top and bottom, and right and left; 350 million years before tetrapods – the first four legged creatures that gave rise to all birds, reptiles, mammals and amphibians – came into existence; and 500 million years before the emergence of dinosaurs. Since then, we have followed very different evolutionary paths. We humans exist out of the sea with lungs to breathe air, a spine down our back, and a central nervous system linked to a large brain.

The cephalopod branch of life, on the other hand, acquired an external shell rather than a backbone, which was eventually lost or internalised by the time octopuses and squids came into being. The ammonite is a cephalopod from the Jurassic and Cretaceous periods, and its impressive protective shell structure is the reason it has been so well retained in the fossil record. The octopus liberated itself from the weight (and protection) of this shell but retained the tentacular limbs, the three hearts pumping blood rich in copper, and gained its own uniquely complex nervous system.

The eyes of an octopus are surprisingly similar to our own, with the only significant difference being the location of the retina. Octopuses have strong eyes for a sea creature, and the similarity between our eyeball anatomies are unlikely a result of our distant common ancestry, but rather an example of evolution independently creating the same eye design at least twice. Our common ancestor, the flatworm, may well have been equipped with a simple nervous system and primitive light sensors we might call ‘eyes’, but they weren’t anywhere near the complexity of either ours or the octopus.

The octopus’s nervous system, on the other hand, is quite unrecognisable from our own. Although complex and large like ours, most of the nervous tissue is clustered into bundles called ‘ganglia’ located in the tentacles rather than one large central unit like the vertebrate brain. It has somewhat of a central brain as well, but the ganglia have a fair amount of autonomous control over each tentacle. This means the tentacles receive their own information and keep a local short-term memory, communicating with one another and only following orders from the brain if they really must. 

What this unfamiliar neural anatomy implies for the octopus’s state of consciousness and mind is a subject of both philosophical and scientific head-scratching; could it be that the octopus exists as a collection of consciousnesses in interplay? Or is it redundant to label the experience of an octopus relative to our own? What is consciousness anyway?

Another Type of Clever?

Much like Arrival’s heptapods, there seems to be a lot we can learn from the octopus. They exemplify advanced life in separate evolutionary lineage, and how an intelligence different from our own might look. The octopus’s intelligence is one of curiosity, playfulness, and mischief. In captivity, they are often noted to have an apparent perceptive awareness of their unfamiliar surroundings. Eyeballing the researchers and behaving troublesomely, research papers on octopus intelligence have mentioned their various quirky behavioural traits.

‘Curiosity’, ‘fiendish’, ‘mischief’, ‘awareness’, ‘play’

The first example of such was described in a paper released in 1959, in which the researchers bitterly commented on a certain octopus by the name of Albert misbehaving during experiments. Rather than pull a lever to receive sardines, Albert would busy himself trying to break the lever clean off by wrestling with it for hours, or spend his time repeatedly spraying one particular researcher he didn’t seem to like. Albert did not make many friends in that lab, nor did he do any favours for the researchers’ data.

Other reports describe octopuses attempting to escape captivity at precisely the moment they are not being watched, maintaining eye-contact with the researcher until they turn away, and only then making a break for it. As well as escape attempts, octopuses have been seen to engage in play. Not many organisms express curiosity for the sake of it with an inedible object; but octopuses do, and this is one of the things which sets them apart from most other invertebrates.

A key observation regarding octopus intelligence was made in 2009 when one was spotted with a coconut shell. The octopus was observed hiding inside two halves of a coconut shell, dismantling it, lugging it around throughout the day while it went about its business, and reconstructing it to hide in again when retreating to sleep. This behaviour demonstrates not only the use of tools which is rare in itself, but also a capability to grasp that two halves of a coconut are part of a greater whole, that can be deconstructed and rebuilt again when needed. 

The indications are clear. Octopuses are intelligent creatures with a mind which works very differently to our own. They show not only intuition when observed, but also individual personalities, usually quite fiendishly with a targeted spray of water. There’s still a lot to understand about how their neuronal activity is organised and how its decentralisation affects the existence of such an organism. The short lifespan of five years maximum, and their relatively unsocial lives also brings into question how different their intelligence is to our own, and how it came into existence. Divers greeted by the animals during their exploration of the sea bed often describe a sense of mutual awareness of each other, and I think it’s important that this awareness is extended beyond the seas; the awareness that ours isn’t the only type of intelligent life possible and that maybe, like with the heptapods, we should be listening and learning from their secrets.

Written by Marlon Jasielczuk-Lando and edited by Ailie McWhinnie.

Marlon’s thoughts… I must credit the book ‘Other Minds’, by Australian Philosopher of Science Peter Godfrey-Smith, for inciting my interest and inspiring me to write this article. It’s a great book on the subject, written with warmth for the octopus and insight on the scientific and philosophical technicalities. I would recommend the book to anyone who wishes to continue their exploration of these other minds, so unlike our own. Following on from the discussion of consciousness, I would prompt you to philosophically consider:

How is it that our consciousness relates to that of the octopus – is consciousness about the physical embodiment of the mind?

Do you think the continuous stream of colour changes in the octopus’s disguise is representative of some kind of internal dialogue, if so is that internal dialogue the way we define consciousness?

Find me on… Facebook @Marlon Jasielczuk-Lando, Instagram @marlonnjl

One thought on “An Alien in Our Sea: A look at the intelligence of an octopus

  1. Betty. White

    Good morning my name is Betty White I’m an independent science researcher I love her science and I study the Earth and the oceans I have discovered a lot of things because I have been gifted with science visions that I receive through imaginations and experiment with science there are a lot of things that other scientists never discover but I have discovered I want to share my experience with other scientists thank you so much and have a wonderful day.

Leave a Reply

Your email address will not be published. Required fields are marked *