We humans pride ourselves on being the most intelligent creation on Earth. We consider other vertebrates intelligent, like the chimpanzee and dolphin.
However, it seems as if we are still struggling to understand an intelligence of a different dimension that belongs to the octopus, which is by the way, an invertebrate. So alien are its looks that H G Wells, in his famous sci-fi, War of the Worlds, described his alien protagonists as having features like those of the octopus — the round head and its protruding tentacles.
A friend of mine, Partha, had a pet octopus and he still marvels at how he was intrigued by its eyes as their gazes met. Much like our eyes, their eyes have a cornea, an iris, an accommodating lens, and a retina. As romanticised as it sounds, my friend thought the eyes spoke of some kind of intelligence in that boneless, nearly-gelatinous being moving weightlessly in the water.
Do you know that it is extremely difficult to keep an octopus in a tank? As Sy Montgomery states in Inside the mind of the Octopus, “here is someone, who, even if she grows to one hundred pounds, stretches more than eight feet long, could still squeeze her boneless body through an opening the size of an orange!” They escape frequently and have been found on carpets, along bookshelves, in a teapot (!) and inside aquarium tanks of other fishes, eating them up!
According to a famous century-old story from the Brighton Aquarium in England, an octopus got out of its tank at night when no one was around, went into the next tank, ate a lumpfish and went back into its own tank, sitting quietly the next morning as visitors looked on. A lot of lumpfish went into Mr Octo’s stomach before people figured out what was happening.
Partha told me an interesting story of how when he gave his pet octopus pieces of coral, it actually made a house out of it. Octopi have been seen to excavate coconut shells out of loose mud by probing with their muscular arm and rotating them out. They scamper off with the halved coconut shells, reassemble them in the original closed coconut form and then sneak into them. Simply carrying the shells around without using them is more like us walking around with a folded umbrella tucked beneath our arms. It only becomes useful when we open it for protection against the sun and rain. Similarly, the coconut shell becomes useful when the octopus turns it up and climbs inside it. The use of tools, along with foresight and planning is enough to be tagged as intelligent. They can navigate their way through mazes, solve problems quickly like opening screw-top jars and remember solutions. In an experiment, an octopus was given plastic pill bottles. Soon after, the researchers were elated to see that it was sending the bottles to the other end of the aquarium by blowing ‘carefully modulated’ jets of water through its funnel and the water flow was sending it back, much like we bounce balls back and forth.
Only intelligent creatures like crows, dogs and dolphins can play. They are also known to have personalities — shy, emotional or indifferent.
The ancestors of octopi had shells much like snails do but in the course of evolution octopi lost their shells, maybe because without the shell-weight, they gained more speed to hunt prey or evade predators.
While crabs are their favourite, they feed on a wide variety of prey — each demanding a separate hunting strategy — camouflaging for stalk and ambush killing, shooting through the waters for catching fast prey, crawling out of water to capture escaping prey. But losing its shell meant less protection against predators. It had to take up different avoidance strategies — flashing warning colouration to scare off predators, changing colour and shape to camouflage, sealing its cave door with stones. This ensured that only the smartest and fittest octopi survive.
So do they have big brains? Well they certainly have the largest brain among invertebrates — the size of a walnut. Not as big as ours, eh? Well, then let’s look at the number of neurons — a measure of intelligence. Human brains have a 100 billion. An octopus brain has 130 million. But hang on, only 2/5th of its neurons are in the brain, the rest are in its arms, as if each arm has a mind of its own! In an experiment, an octopus’ arm was cut off. Not only did the arm crawl away on its own, it found a food item and tried to pass it to where the mouth would have been had it not been cut off!
As scientists still try to understand the mind of the octopus, I am reminded of Aristotle’s comment on it – “It is a stupid creature, for it will approach a man’s hand if it be lowered into the water.” Wonder why it never occurred to him, that the invertebrate is in fact curious.
Coming back to Partha, he tells me how, when he reached home and released the octopus into a bigger tank there was an accident. The octopus saw an anemone in the tank, got alarmed, squirted its poison ink and died. Perhaps, if it had a little more time, it would have figured out that that was not the best thing to do.
