‘I’d like to beOctopuses Garden; Abbey Road, Ringo Starr and The Beatles, 1969
Under the sea
In an octopus’s garden
In the shade…’
Conundrum. What has six arms, two legs, three hearts, a foot next to its head, a beak, breathes water and has two thirds of its brain in its arms? Possible answers are a Kraken, a Gorgon or an Akkorokamui, all mythological, but the accurate answer is – an octopus. These amazing creatures have become objects of focus recently with the release of the incredible documentary My Octopus Teacher, which has now deservedly been nominated for an Oscar. We humans are surrounded by millions of forms of alternate life, but sadly we tend to see them mostly as food, pets or pests. When the intelligence of our fellow earthly travellers is revealed, it often comes as a surprise to us bipedal beings, languishing as we do at the top of the food chain. Which makes documentaries of this sort absolutely invaluable; humans need to understand that whilst we are unique, we are not the sole reason for life on earth, nor are we the only intelligent creatures.
Octopuses (yes, that is the official plural – you can use octopodes if you are showing off, but never, ever, octopi; that is just wrong on so many levels) are as alien in form as it possible to get from our humanoid structure. As mentioned in the opening sentences, an octopus is built around a completely different basic plan. The ‘foot’ that is next to its head is a mollusc foot; not a five-toed walking platform like you have under your leg, it was originally the appendage that molluscs use to glomp onto rocks. In octopuses it has evolved into ‘arms’ that surround its mouth; these are made up of three sets of matching arms used for foraging, and a set of two rear appendages that are used for locomotion on the seabed. We’d call them ‘legs’, but once again there is the danger of anthropomorphising these vastly different creatures; they don’t comply to our rules at all.
The circulatory system of an octopus is also a complex arrangement by human standards. Octopuses have three hearts; a systemic heart that circulates blood around the body, and two branchial hearts that pump blood through each of the two gills. The systemic heart is inactive when the animal is swimming and thus it tires quickly and prefers to crawl. (That’s about the only part that we humans can identify with; I can think of many times during sport when I’d have been happy to crawl rather than cycle up a hill, bowl another over or tackle another flyhalf.) The octopus brain is equally alien when compared to our cranium-based thinking machines, and octopuses have the highest brain-to-body mass ratio of all the invertebrates: its highly complex nervous system is divided into a cartilaginous capsule in the head, which contains about a third of the neurons, and the rest, which is found in the nerve cords of the arms. Switch off an octopus’s main brain, and its eight appendages carry on regardless, in a variety of complex reflex actions. (I must admit I have met some humans who can operate like this, mostly in bureaucratical positions: in the navy this is known as ‘under way, but not under command’.) Those intelligent arms can also detect light – good for reaching around corners to catch hidden prey.
Octopuses are living underwater drones. They have two special organs called statocysts attached to the main brain, and these allow the octopus to sense the orientation of the body; detect angular acceleration and positioning relative to gravity. An autonomic response keeps the octopus’s eyes orientated so that the pupils are always horizontal – somewhat like a gyroscope. Those eyes, by the way, have colour vision, and can see the polarisation of light – something we need expensive sunglasses to achieve. The colour vision is put to its best test during mating displays, as octopuses also have the ability to change the colour of their skin pigment – ideal for camouflage, but really great for dressing up to impress the local female population. But, sadly, there is a downside to capturing the heart of a local octopussy: once they have gone through the mating ritual and done the reproductive deed, both male and female octopuses…die. The female stops eating during the carrying of the fertilised eggs, and between forty and a hundred days later, she dies. The male doesn’t even make it this long: after mating he becomes senescent and dies a few weeks later. Who would want to lose their virginity under these demanding conditions?
There is so much more. The intelligence and communication of the octopus is examined in the documentary; if you haven’t seen it, it is wholeheartedly recommended. At Waterfront Charters we cannot confess to being able to show you octopuses on our cruises; that would be a remarkable sighting. But what we can do is continually extoll the wonder of the marine life that lives in our oceans, and carry on with our mission of protecting and conserving that environment. The other creatures that present themselves to us are equally worthy of understanding and appreciating; join us on any cruise to participate in the wonder and delight of the Atlantic Ocean.