Six Things You Didn't Know About Octopuses

I’ve covered a lot of topics on this meandering blog over the last year or so, but it seems that I have inexplicably not written a post on octopuses, nor can I fathom how I could have made such a glaring oversight.  Whaddup wi' dat?

As someone who has difficulty coordinating the motion of a mere four limbs. I’ve always had immense respect for the octopus, who must manage eight.  

You’d think, extrapolating from the above, that I would therefore revere millipedes, but in fact I find them rather dull.

Anyways, without further ado, six things you didn't know about octopuses...

1.  The plural of octopus is not octopi.

In the Latin, regular masculine nouns end in a –us when they are singular.  When you pluralize the noun, you use the suffix –i.   In English, we’ve sometimes kept that for words derived from the Latin, and thus the plural of focus is foci.  Or stimulus and stimuli.   Or cactus and cacti.  Or how about this one:  What do you call a mushroom with a nine inch stem?  A fungi to go out with.  Ba da boom!  I’ll be here all week, folks.  But octopus is derived from the Greek, not the Latin (oktopous, meaning “eight footed”) .  Following Greek declensions the plural of octopus would correctly be octopodes.  But that would probably just confuse most folks, so the most acceptable plural is regular old octopuses.

This is an octopi.

Actually, that reminds me, it's March 14 today (3.14) so happy Pi Day everybody!

So the next time you are in the midst of discussing cephalopods and some pedant tries to correct you when you say "octopuses" by telling you the plural is octopi, you can actually out-geek him, snort derisively and proclaim loudly, “Pshaw! Clearly you are unaware that the etymology of the word is Greek, not Latin.”  Then send him to the corner to try to figure out the plural of doofus.

The adjective for octopus is correctly octopodal, as in “Cthulhu’s face is octopodal.”  But I think octopussy would be way cooler, as in “This squid tastes kind of octopussy.”

2.  Octopuses Could Be Aliens

Octopuses are pretty weird looking--gelatinous, translucent, boneless masses, all giant head and tentacles, and a beak with a tongue that has teeth built into it.  If you want to make a really freaky looking alien, as a matter of fact, you’re well off dropping a little octopus in.  H.P. Lovecraft was perhaps the first to clue in to this.  Lovecraft is a writer from the early 20th century of cult status who founded the "formless dread" school of horror.   He describes the indescribable Cthulhu—the Thing That Should Not Be—as “A monster of vaguely anthropoid outline, but with an octopus-like head whose face was a mass of feelers, a scaly, rubbery-looking body, prodigious claws on hind and fore feet, and long, narrow wings behind.”  Lovecraft even once sketched Cthulhu—apparently taking a dump. 

"Hey, Ineffably Abominable One, how about a courtesy flush?"

Then there’s the Daleks, the arch-enemies of Brit eccentric time-travelling demigod Dr. Who.  These creatures look like tin cans with an egg whisk and a toilet plunger sticking out of them, and strike terror across the universe despite their seeming inability to climb stairs.

But what does the inside of a Dalek look like? 

Yup, definitely octopussy, I think you’d agree. 

How about this alien?  Ring a bell?

Octopussy, with a hint of arthropod.

3.  Octopuses have been granted honorary vertebrate status

Octopuses are thought to be the cleverest of all invertebrates (i.e. animals with no backbone), demonstrating the ability for both long-term and short-term memory.  They can solve mazes.  They use tools.  They can screw open jars.  They can solve second-order non-linear differential equations. 

They are such clever and inquisitive little critters that in England they have designated “honorary vertebrate status.”  That might not sound like much to you and me, but, with respect to experimenting on animals, it means you can’t dissect them while they are still alive and stuff.  Something I’m sure the octopuses appreciate, anyway.

4.  Octopuses Have an Odd Intelligence

We know that octopuses are smart, but smart like Dustin Hoffman in the Rain Man.  There’s some formidable intellect at work there but it is very different than ours.  There is an active debate in the biological community as to the intelligence of octopuses, going back all the way to Aristotle, who called the octopus a “stupid creature.” 

The current orthodoxy is that the octopus, having evolved in a completely different world than the one we did, has a completely different intelligence suited to its survival.  One theory has it that the octopus abandoned its shell (which most other mollusks have kept) and suddenly found itself soft, slow and delicious—a fatal trifecta in the Darwinian stakes.  So they developed intelligence as a defence mechanism.

Octopuses have pretty big brains, gargantuan by mollusk standards.  Some half a billion neurons, on average.  Not quite up there with human beans, who have somewhere around 50 billion, but nothing to sneeze at either.  They regularly escape containment in ways that their human captors can’t even understand, except to say that all the fish in the adjacent fish tank are gone and their octopus has gotten fat.  They are regular Houdinis apparently.  One reason is that octopuses can escape out of a hole the size of one of their eyes.

Octopuses also have very distributed brains.  Two-thirds of their neurons are outside their brain.  Some octopuses can autotomize—that is self-amputate—its limbs in times of danger.  Now since the neural net of an octopus is distributed throughout its tentacles, the amputated tentacles actually carries some intelligence with it, so the arm has the “presence of mind,” if you will, to taunt the predator while the octopus disappears in a cloud of ink.

5.  Octopuses can Taste With Their Arms

The suction cups on an octopuses arms (apparently they are not called tentacles.  Whatevs.) are equipped with chemoreceptors that taste what the octopus is holding.

6.  Octopuses are the World’s Greatest Mimics

In comparison to a Mimic Octopus, calling a chameleon a mimic is like calling the guy that flips burgers at MickeyD’s a chef.  I mean, what can a chameleon do?  Change colour slightly.  Big whoop.  The Mimic Octopus, like the chameleon, uses chromatophores to change colour (Chromatophiores are cells that contain pigments that can be released through muscular control, thereby effecting camouflage).  Octopuses have a palette of four colours to choose from.  But octopuses also have iridophores, which reflect light, effectively making them just about invisible in a marine environment.  Not only that, they can control the texture of their skin to match their surrounding environment, be it coral, rock or sand.  Not only that, but the Mimic Octopus can change its shape to look like a rock or a predator, such as a sea snake or lion fish.  Ah, the advantages of being boneless!  And not only that, but they also change their behaviour to mimic the predator they are impersonating.  Now that is camouflage, baby! 

See the video below for a flabbergasting example. 

So that’s octopuses.  Pretty darn cool.  They're slimy.  They can change colour and shape.  They can become invisible. They’re smart.  They can escape through a hole no bigger than their eye.  They are ...(ahem) ... well-armed.  They can squirt ink.  They can self-amputate limbs which become almost fully autonomous mini-octopuses themselves, and then grow the arm back later.  They eat sharks.  They have extremely powerful tentacles that can actually taste you, as well as paralyze you with venom so that you are perfectly aware, but powerless as you are inexorably drawn to its central feeding beak where they drill their tooth-lined tongues into you to suck your guts out.

Cool critter.