We fancy ourselves pretty fortunate -- sometimes even divinely chosen -- for possessing a magical opposable digit. Two of them, no less! We can wind antique watches; we can milk cows; we can throw a knuckleball. I mean, my dog can't open his own food bin. Even the ever-admired elephant struggles with holding a simple rope. A rope! So, clearly, we win. Thanks, thumbs!
Well, I'm sorry to say, you can take your thumbs and shove 'em. You should be embarrassed by your thumb pride, your thumbism. This thumb-centric worldview is a pinched one, to say the least.
Thankfully, the octopus is here to give you a hard lesson in thumbleness.
The octopus, you say? So you'd like to see an octopus try to use a pair of chopsticks, right? The octopus doesn't possess a single finger -- let alone an advanced appendage resembling the crowning achievement of the primate hand.
Well, if it had any sense of humor (and science on that is scant), the octopus would be chuckling to itself. As it weaves together delicate strands of its eggs. As it opens a jar in less than a minute. As it rips open a delicious oyster for lunch. All, of course, without lifting a finger, opposable or otherwise. Chuckle, chuckle, slurp.
Meet the octopus sucker.
Humans have tried for ages to copy this magnificent product of evolution -- from flexible suction cups developed in the 19th century to new 3-D printed robotic suckers that still, well, kind of suck. Basically, we have failed.
For starters, octopus suckers are strong. Thanks to microscopic ridges on their insides, suckers create a watertight vacuum seal that can match the molecular strength of water itself. Regardless of how smooth or bumpy the surface is. Bumpy oyster shell? No problem. Suckers, engage! And an octopus can rip that puppy open in no time flat.
But they are hardly stuck sucking. Each octopus sucker (and octopuses have hundreds of them on each arm) can engage and disengage independently. This means the octopus can pick up and drop objects at will. They can even hand something off, so to speak, to other arms. Or they can pass something -- perhaps a small rock or even a pestering hermit crab -- up or down its arm one sucker at a time, a move some researchers have nicknamed "the conveyor belt."
These tiny appendages also function as finely calibrated pincers. The flexible outsides of the sucker can bend and fold to handle even the finest object. As the female octopus lays her hundreds or hundreds of thousands of tiny eggs, she spends days to weeks carefully weaving each egg's thin tail into a long strands. Each one of these delicate egg clusters she will affix to the ceiling of her den.
For extra mobility, each sucker also stands atop a flexible, movable stem. With this stalk, the sucker can bend and move to point in almost any direction. A speedy octopus in Australia recently used its many bendable suckers to open a screw top jar is less than a minute. Look, ma, no hands!
Are you still scoffing at these basic abilities, over your sushi eaten with such exquisitely wielded chopsticks? Well, the octopus's suckers also allow it to use tools. In case you haven't seen the video (available here), a population of octopuses has been taking up coconut shell halves to use as shelters on the go. (Planning + object application = tool use.) How do they carry around these shells -- and keep them closed when a curious human comes swimming by? Suckers!
Still not convinced that you should have sucker envy? Pick up one of those sushi rolls you're eating. Place it in your hand for just a second. Can you taste it? No? I didn't think so. The octopus would have been sampling the flavors of the seaweed and salmon this whole time. How? Its suckers can "taste" their surroundings. If it wants to know if that thing it's holding is edible, no need to bring it all the way to its mouth -- risking a poisonous nibble or a crab's pinch. It can just sample the chemical makeup with one of its sucker's many chemosensors. This may even be the way octopuses find other octopuses to mate with. (Eau de mature male octopus, anyone?)
And if an octopus ever loses part -- or all -- of an arm from a hunting accident, rough courtship, or other mishap, the arm will grow back, suckers and all.
So next time you're feeling pretty awesome for being able to pick up a dainty teacup or scoop out some food for your poor unidirectional-digited dog, just remember octopus suckers could twirl that teacup and dance those kibbles up and down its arms. Tasting them all the way.
Yes, you might say I'm a sucker for the octopus sucker (there it is). But I am happy to keep them at arm's length. Getting too close can lead to a messy entanglement. If you ever come into contact with them -- and let them taste you -- you'll likely walk away from the encounter with a collection of miniature hickeys, just as a little reminder. Perhaps these dexterous invertebrates have a sense of humor after all.