What do you know about octopuses?
December 31, 2020 11:20 PM   Subscribe

Please tell me the most interesting facts you know about octopuses.

I just read a book about octopuses and I want to know more.
posted by aniola to Science & Nature (25 answers total) 26 users marked this as a favorite
 
Response by poster: PS please cite your source
posted by aniola at 11:22 PM on December 31, 2020


octopi // octopuses // octopodes
posted by oceano at 11:27 PM on December 31, 2020 [2 favorites]


I know almost nothing about them except for their ability to squeeze through small holes.
Video is from OctoLab TV which is a youtube channel you might enjoy.
posted by NotTheRedBaron at 11:57 PM on December 31, 2020 [2 favorites]


They dream
posted by Faff at 12:47 AM on January 1, 2021 [1 favorite]


Do you know about Peter Godfrey Smith’s book and works about octopuses minds and cognition? He’s a philosopher and cognitive scientist who has written a lovely accessible book called “Other Minds”. An entertaining review by Amia Srinivasan appeared in the London Review here.
posted by Joeruckus at 2:00 AM on January 1, 2021 [3 favorites]


Octopuses are somewhat decentralised: they can sense light with their skin, without needing input from eyes, and use that light signal to adjust camouflage (nyt-2015, jeb-2015-a, jeb-2015-b ); their arms can perform some actions/reactions autonomously -- even after a period of time severed from remainder of octopus (sciam-2013 )/

This crop of octo-links gleaned from science fiction author peter watts' blog , which offers octopus-mind-meld-fiction.
posted by are-coral-made at 3:05 AM on January 1, 2021 [2 favorites]


OK, so, octopuses really like eating crabs, right? A while back I became intrigued by the question of how they actually go about catching and eating crabs: octopuses are famously soft and squishy, crabs are famously.. not squishy; how can an octopus kill a crab without getting torn to bits itself? I went down a bit of a rabbit hole and as far as I can tell this is what goes on:

- the crab (or shellfish or whatever) gets injected with digestive enzymes which dissolve its insides; the octopus waits maybe 30 mins for this to work, then sucks up the delicious crab milkshake.

- in order to hold it still for 30 mins, the octopus first injects the crab with neurotoxins which paralyse it.

- in order to do this, the octopus first drills a hole in the shell. It has a special organ, the salivary papilla, for doing this, which is not just a kind of scrapy drill but can also squirt special shell-dissolving fluid.

- in order to minimize the amount of time spent trying to drill holes into the shells of uncooperative crabs, the octopus will normally go for the eye socket first, because it's more vulnerable. They know where the best drilling spots are for different prey species.

- in order to soften up the shell for drilling, the octopus will use its radula, which most texts will describe as being like a rasp or file, but is more like some kind of nightmare belt sander. I couldn't find a decent picture of an octopus radula, but this clip of its relatively placid cousin the gumboot chiton should give you an idea.

- in order to do all this, the octopus (which is basically made of muscle) holds the crab so tightly that it's incredibly hard to work out what's going on inside, so that researchers resort to putting microphones in the tank and listening for the drilling noises.

TL;DR if you're a crab then octopuses will try to stab you in the eye with nerve poison before liquefying your insides and drinking your living innards; their mouthparts are like something from HR Giger's worst nightmares.
posted by doop at 3:52 AM on January 1, 2021 [36 favorites]


I don’t have any facts at the ready—it’s early, after all—but the book Soul of an Octopus by Sy Montgomery is really fascinating and filled with octopus info.
posted by bookmammal at 5:01 AM on January 1, 2021 [5 favorites]


The males (of all cephalopods) have a special penis arm called a hectocotylus, often detachable.

They use their siphon for propulsion but also pooping. And sex, when appropriate.
posted by SaltySalticid at 5:39 AM on January 1, 2021 [1 favorite]


According to this study, cephalapods are unique among animals in that they are super smart yet live short and almost entirely solitary lives.
posted by Morpeth at 6:03 AM on January 1, 2021 [1 favorite]


They can taste through their arms and change TEXTURE at will (not only color like many camouflaging critters). They can use tools!
posted by erattacorrige at 6:04 AM on January 1, 2021 [1 favorite]


They punch fish out of spite. Link goes to NPR but there’s a link to the journal in the article.
posted by Bunny Boneyology at 7:04 AM on January 1, 2021 [2 favorites]


If a male tries to and/or succeeds in mating with a female but she is hungry, she might eat him.
posted by pangolin party at 8:38 AM on January 1, 2021


As of two days ago I now know that at least one octopus could outwit a pajama shark by riding it, rodeo-style. Source: My Octopus Teacher. Watch for this and a whole slew of other behavioural delights (and because it is a beautiful film).
posted by freya_lamb at 8:43 AM on January 1, 2021 [7 favorites]


I hesitate to mention this one, since I feel pretty sure anyone interested in octopuses will have heard it when it had its 15 minutes of fame a few years ago, but-- the fact that octopuses are like absolutely no other living creature in so many ways, and that they appeared suddenly in the timeline of life, led 33 scientists in a peer-reviewed study to suggest (only half jokingly) that they must be of extra terrestrial origin. News explainer article with basic summary here.
posted by seasparrow at 9:17 AM on January 1, 2021 [4 favorites]


Ever since I learned how intelligent they are, I refuse to eat them. It's a bit like eating a border collie.
posted by McNulty at 10:50 AM on January 1, 2021 [10 favorites]


They don't have blind spots like vertebrates do because their eye is constructed so that the nerve fibers route behind instead of before the retina.
posted by foxfirefey at 10:58 AM on January 1, 2021 [1 favorite]


Their camouflage ability is wild--the top layer layer of skin has organs called chromatophores that they can expand and contract at will, and the next layer down is iridescence. They can control skin texture with papillae that can be squeezed to go up or down. Seriously watch the video at the bottom of the page if you haven't seen it before. Also, it seems like their skin can also sense light!

The brain of an octopus is basically spread throughout their entire body--they have more neurons in their arms than in their central brains, so their arms can act independently and can taste and smell.

Also they have 3 hearts. Cephalopods are my favorite creatures, I could go on and on!
posted by lemonade at 11:33 AM on January 1, 2021 [2 favorites]


Response by poster: Please do!
posted by aniola at 11:39 AM on January 1, 2021


Wait I see you read a book, are we telling you things already in the book? Not-book things:
Video of the objectively cutest octopus in the world
Video of the objectively cutest cuttlefish in the world
True Facts about the Octopus

Octonation is the Largest Octopus Fan Club, for your daily octopus fix look for them on your social media platform of choice
posted by lemonade at 11:47 AM on January 1, 2021 [1 favorite]


Blanket Octopus females are 10,000 times bigger than males.
and incredibly beautiful
posted by OHenryPacey at 12:00 PM on January 1, 2021 [3 favorites]


This is a sort of lateral octopus fact but librarians worldwide like to teach people about the Pacific Northwest Tree Octopus (note: not a real thing) as a way to teach people about how to learn internet media literacy. You'll note that page has a sidebar of real (and current) octopus facts.
posted by jessamyn at 12:24 PM on January 1, 2021 [6 favorites]


They can open jars from the inside and escape.
posted by FencingGal at 6:04 PM on January 1, 2021


John Oliver put 30 seconds on the clock for people to experience joy about the results of the 2020 election however they wanted to. He spent the time "dispensing excellent facts about octopuses" over footage of people celebrating the results of the election.

tl,dw; studies say octopuses become more social when they're on ecstacy.
posted by bendy at 1:29 AM on January 2, 2021 [2 favorites]


They can have fits of pique.
posted by agentofselection at 12:55 PM on January 5, 2021


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