A group of us were at dinner in a local Chinese restaurant, celebrating (if that is the correct word) the departure of a valued colleague, off to build her career. We were scientists, educators, environmental managers, planners, and other folks with jobs in the community. The conversation ranged widely, but at one point I heard one of the scientists speculating about whether octopuses were aware. This idea got batted around a bit, we enumerated species for which there is some evidence of awareness, even self-awareness, and we wondered about creatures for which there is, so far, no such evidence.
(Establishing whether an animal is aware is difficult. Asking them does not work. Asking other people does not work either, because they might lie, telling you what you want to believe. At one level I only know that I am aware, and other people might doubt that, especially if they see me sleeping in front of the TV.)
The whole question of complex neural processing in other species is fascinating to me, because I began my research career studying fish behaviour. One tenet of that field of study was to be strictly objective, to rely solely on what you could see, or otherwise measure directly, and to avoid any tendency to think of the animal as a ‘little human’. Intention, planning ahead, and thinking about things might be going on, but we should not start with the assumption that they were.
I suspect the number of aware species will eventually turn out to be far larger than we mere humans suspect. They will not be ‘little humans’, aware like we are aware, but they will have their own forms of awareness.
That is still sound advice for the behavioural biologist, and yet, the possibility that at least some other creatures are aware is not only impossible to resist, it is almost certainly correct. And I suspect the number of aware species will eventually turn out to be far larger than we mere humans suspect. They will not be little humans, aware like we are aware, but they will have their own forms of awareness, and I for one believe the octopus will be on that list of species.
What fascinated me, as I reflected back on our conversation that evening, was the reaction of the non-biologists in the group. They were quite surprised that we biologists seemed to think awareness in an octopus was a real possibility. They were surprised when evidence of awareness in other species was mentioned; presumably they did not know any such evidence existed. They were a bit confused by the idea that other species could be aware, but aware in different ways to the way we are aware.
But overall, as they got used to what we were saying, they warmed to the idea of animal awareness, and they welcomed it. Many of them no doubt would like to believe animals like dogs and cats and horses are aware, perhaps do believe this, but have come to learn that scientifically this may not be correct. That scientists were taking the idea seriously restored their confidence in their own hunches about other species. Of course, once we come to accept that many other species are aware, and even self-aware, how we treat other species becomes more problematic. Does an aware creature have certain inalienable rights? We did not go there — the sweet and sour chicken was too good to delay our meal.
Charity to others
The next day, I chanced to flip through the pages of the local newspaper. When you live in the country, the local paper becomes an important source of gossip, and of the minor goings-on around town that are important in how the local community functions, but of absolutely no import on the wider stage. You learn quickly that reading the local paper can be a valuable ritual. On page three there was a charming story about how traffic came to a complete halt on one of our rural roads, because two cars stopped (one going in each direction). Why did they stop? Because the drivers were helping a snapping turtle across the road.
A page further on, there was the tale of another snapper, this one for some reason named Sheldon (although I doubt the turtle was aware of that name), which had been discovered in some distress with a fishing lure through his foot and further hooks down his gullet. This turtle received emergency medical care from an EMS professional on his way home from work, and was then taken to a wildlife trauma centre some distance away, where he underwent emergency surgery to remove three hooks from his digestive tract. Sheldon is reported to be recuperating with a plan to return to his lake within a week.
Snapping turtles, Chelydra serpentina, are often seen on our roads, and rarely in our waterways (they are there, but tend to keep away from us). Photo: Michael H. Schwartz. Creative Commons BY-NC-ND.
Bear in mind that around here, snapping turtles are reviled almost as much as the badly misunderstood beaver. They will bite through broomsticks. They remove your toes if you dangle your legs in the lake. They are vicious, evil, mendacious creatures that lurk menacingly waiting to grab unwatched toddlers wading in the shallows. And they eat beautiful baby ducklings (that last one is true). Yet, here were two articles about people taking time out of their busy days to care for snapping turtles. I’m beginning to think that there might be hope for the human species after all. It seems we are starting to show some respect for other species.
Given that a large snapping turtle could be 50 to 75 years old, they deserve some respect. And so do those octopuses with their molluscan awareness of their watery worlds. If we can foster a sense of respect for the other creatures on this planet we call ours, maybe, just maybe, we can develop the will to get busy correcting some of the egregious damage we have been doing. And none too soon.
Understanding the octopus
So what do we know about octopuses? Along with their cousins the squids, cuttlefishes and nautilus, they are the most complex of the molluscs, and intellectually they leave the oyster (also a mollusc) in the mud, along with a wide range of other molluscs. They are not at all like us, which makes understanding them a bit more difficult. With their eight tentacles arrayed around a central mouth, underneath a large head with two well-developed eyes, and with other bits and pieces curled about (molluscs seem to love to curl, although the snails take this to an extreme) somewhere hidden deep within the head/body, they do not even present in the usual bilateral, right side/left side, top/bottom, front/back way that most other animals do. They are the original shape-shifters, a trait which makes them difficult to keep in an aquarium because they can squeeze out through the tiniest gaps.
The coconut octopus uses nut and clam shells for protection and will carry the shells with its inner suction cups while walking on the sea floor with the tips of its tentacles. When threatened, it will quickly close the shells around its body. Photo: Nick Hobgood. Creative Commons BY-NC (cropped).
They have excellent vision, and their eyes are architecturally superior to those of vertebrates like us, simply because they have the retina the right way around. If you remember, our retina has a blind spot right in the centre of the field of view, because the nerve axons emerging from the light receptors come forward into the eye, then group together and plunge through the middle of the retina to get out the back of the eye. The octopus, by contrast has its light receptor cells facing into the eye, and the axons come out on the outside of the retina before grouping together to go off to the brain. The vertebrate eye is one of the nicest proofs of why the concept of Intelligent Design is false — it was not designed intelligently, it evolved. But I digress.
Despite their wonderful eyes, octopuses do not see like we do. Their behaviour, particularly their social signaling using colour variations rippling across their surfaces, or their accurate and rapid modification of colour to match the ground over which they are travelling suggest they can see colour, but their eyes contain only a single type of photoreceptor cell. Scientists are still struggling to understand how they can see colour without the usual three types of photoreceptors sensitive to different colours of light. There is some evidence that they can sense colour of surroundings with receptors in their skin, and quite new evidence suggesting that their slit-like pupils assist in colour vision based on chromatic aberration (the slight variation in focal length of a lens depending on the colour of the light).
In very early learning experiments it was shown that an octopus could quickly learn the difference between a vertical dark bar and a horizontal dark bar, but treated a bar slanted at 45 degrees to the left as not different to one slanted at 45 degrees to the right — they could never learn the difference. For us, tilting your head converts one of these pairs into the other, and octopuses can tilt their heads. Don’t ever expect an octopus to be a little human. They definitely are not.
But what about awareness? Well, how about tool use and forward planning? A paper in Current Biology in 2009, by Julian Finn and colleagues from the Victoria Museum in Melbourne, Australia reports just that for the Veined Octopus, Amphioctopus marginatus, observed over sandy/silty substrata in depths up to 55 meters, off Sulawesi and Bali, Indonesia. They repeatedly observed octopuses carrying two coconut half-shells, by holding them under their bodies and more or less walking across the bottom using their remaining tentacles. When they reached a place where they ‘wanted’ to stop, the octopuses would set down their half-shells and then manoeuvre to sit inside one and close the other over their heads. Moving about meant they could forage more widely for prey (octopus are sit-and-wait predators feeding on many different types of prey), while still having protection in the event something came along that wanted to eat them. There is a video here of this incredible behaviour.
Octopuses like these ones are other animals that have talents that at least rival our own. The big snapping turtle in my lake has lived there for many decades before I was here, and surely ‘owns’ the lake as much as I do (I don’t, legally, but each of my neighbour on the lake think they do). Maybe if we recognize such facts, we can begin to recapture that sense of being a part of, of belonging to, and of sharing the world with the other creatures that live here. Once we see ourselves as a part of the natural world, we are more likely to recognize our responsibility to care for that natural world. Nature is not there to be dug up, cut down, killed and skinned, and shipped out, converted finally into so many dollars.
Appreciating the oceans
One final note. We understand and appreciate the oceans far less well than we do the land, partly at least because the oceans are the other. We can live beside, but not really within the oceans, and most of us have scant knowledge of what goes on under the waves. I blogged recently about how we were damaging the oceans. On 3 July 2015, Science published an article on our impacts on the world’s oceans. Under the ponderous title, “Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios”, Jean-Paul Gattuso from the CNRS Institut in Villefranche-sur-Mer, France, and a collection of colleagues from around the world, drew attention to the consequences for the oceans under a high emissions or a low emissions future.
Their two main points were first that the oceans are damaged twice by CO2 emissions — they are warmed and they are acidified — and in that sense get worse treatment than the land, and second, that the changes we are causing to the oceans will continue well past the end of this century, even if we embark soon on aggressive reductions in emissions, that this is the case even for the most aggressive emissions reduction path under consideration, and that we are only beginning to see the impacts on marine systems around the world.
Their article has a relatively accessible front page synopsis, and a main text which is sometimes technical but reasonably accessible with a bit of effort by the reader. And it is one of the rare Science articles on open access — do read it. We need to understand better what we are doing to the oceans, because when we do, we will likely be more motivated to do what we can to bring our pollution under control. If we respect our oceans, that will help too.