Brains in their tentacles ...and they LOVE a fight

Octopuses like partying, too – when they aren’t regenerating or making friends with humans, as revealed in this enchanting book

Many Things Under A Rock: The Mysteries Of Octopuses David Scheel Hodder & Stoughton ★★★★★

Here is a creepy but true thing. When a fisherman hauls an octopus into a large bucket and lops off its arms to cook later for supper, the arms carry on living. More than that, they are positively frisky, climbing out of their prison and making a break for it, slithering and sliding to freedom. If the fisherman chucks the wriggling limbs back in the bucket, they simply set off on a second attempt.

The reason for the octopuses’ tentacles being so clever is because their brains are dispersed throughout their body (we, by contrast, store 95% of our neurons in our noggin). Indeed, one of this cephalopod’s smarter tricks is being able to grow back any single limb that has been bitten off during a fight (and there is a lot of fighting in octopus land, usually between strangers who are trying to turn each other into lunch).

After losing a leg, a wounded octopus will kiss itself better by sucking on the wounded

‘After losing a limb, it will suck on the stump and it will regenerate’

stump, then it will lie low and wait for the limb to regenerate, as good as new. Honestly, it’s magic.

This is just one of the fascinating factoids that marine biologist David Scheel shares with us in this clever book, based on his 25 years as one of the leading octopus researchers in the world.

He explains there are more than 300 sub-species in existence, with more being discovered all the time. These include such scary horrors as the blue-lined octopus, smaller than a person’s thumb, yet perfectly capable of killing a nosy scientist with its deadly bite.

Then there’s the delightfully named ‘gloomy octopus’ which sounds like a character from a children’s book but is a medium-sized species found off the coast of Eastern Australia. It got its name because early scientists thought it led a rather sad, isolated life although, as soon becomes clear in Scheel’s book, it is hard to think of any kind of octopus that positively enjoys a party (it usually ends in fighting).

My favourite, though, is ‘the coconut octopus’, which hangs out in the shallow waters around Madagascar. Sensibly, given how brutal communal life can be, the coconut octopus finds a discarded husk lying on the seabed and climbs into it, then stays very still indeed, hoping no one will notice. As a life philosophy, it has a lot to recommend it.

Scheel has encountered many of these subspecies during his globe-trotting research, but he remains particularly attached to the Giant Pacific Octopus of Western Alaska, where his university laboratory is based.

While not actively aggressive, these 40st whoppers are quite capable of defending themselves if they feel sufficiently disrespected.

Whenadiverswimstooclose,theoctopus’s preferred technique is to grab the intruder in a headlock and, with another of its tentacles, pin the human’s arms to their sides to immobilise them. Next, it cuts off its victim’s air supply by clamping their jaw shut and squeezing very tight.

Shortly after arriving in Alaska in 1995, Scheel hears the story of a diver who got too close to a big octopus and found himself being dragged down and held in a slimy grip for two hours, before the animal’s muscles momentarily relaxed and the man was able to free himself.

Since the diver was on surface-supplied air and connected by intercom there was no real jeopardy, but still... No wonder the local indigenous tribes refer to the octopus as the ‘devilfish’ or, if they don’t want to risk giving offence, ‘many things under a rock’.

Scheel is keen, though, that we shouldn’t treat octopuses as a freak show. One of the most compelling passages in the book comes early and concerns him following a Giant Pacific Octopus, watching as she ripples and propels herself along the ocean bed, as flexible as jelly yet as tough as old boots. And while it remains true that octopuses have their anti-social side – cannibalising their lovers during the mating act is hardly polite – Scheel insists that they are an emotionally demonstrative crew. Indeed, you could say that they wear their heart on their sleeve(s), changing colour according to their emotions.

And those colours, interestingly, are familiar to us. Bright red for anger, white for fear, and a smudgy grey colour for when they are not feeling their best and don’t want anyone to look at them.

If challenged then an octopus will squirt a murky black and brackish ink, made up of melanin and mucus. Quite apart from providing camouflage, this tastes as disgusting as it sounds. Do octopuses have a tender side? Scheel says yes. In captivity they are kept alone for obvious reasons – fighting and eating tankmates inevitably strains the atmosphere – but they seem to crave contact with their human carers.

They often change colour with pleasure, delighted to see their favourite person. But if they don’t like their keeper, then they are quite capable of making their feelings known by squirting them and jetting off to sulk on the other side of the tank.

Scheel reports how ‘Thursday’, an octopus he keeps at home in a large aquarium, likes to come up and bob by him when he is reading the newspaper, as if doing that rude thing of reading over his shoulder.

Thursday also likes to greet Scheel’s daughter every day when she comes home from school and, after feeding, holds hands with her for up to half an hour.

Indeed, octopuses often seem to display the emotional vulnerability of small human children. Scheel tells us of his encounter with one octopus who insists on putting its tentacles over its eyes on the principle that, if it can’t see him, then he can’t see it.

It is enough to melt the stoniest of hearts.

‘They change colour with pleasure when they see their favourite person’