If there's one book you should never judge by its strange and squishy cover, it's the squid — or any cephalopod for that matter.
There's already plenty of proof of octopus intelligence — from their wily hunting skills to their surprisingly rich social lives. But squid, despite having been around for the last 500 million years, tend to ooze under the radar. They're studied far less than octopuses. And the scant headlines they make are of the shock-and-horror variety (Squid impregnates diner's tongue!) rather than an honest appreciation of the creature's capacious mind.
And yes, there is a mind in that tangle of tentacles and arms and suckers, even if there's no spine at all. But what makes that mind so formidable?
Well, there are at least four things that we know of:
1. They can edit their own brain genes.
Imagine being able to defy your own genetic code and rewire it as you see fit. That's precisely what squid and other cephalopods can do. Rather than being slaves to their DNA, squid overwrite their programming on the fly. They do it, a 2017 study found, by messing with the messenger. In most animals, genetic information is decreed by DNA. Then RNA faithfully carries those edicts to the organism, which shapes the body's proteins.
Most animals are the net sum of information baked into their DNA — and dictated to the rest of the body.
But DNA isn't the boss of squid.
Instead, the researchers noted, squid interfere with the code as it's being transmitted by RNA.
The system may have produced a special kind of evolution based on RNA editing rather than DNA mutations and could be responsible for the complex behaviour and high intelligence seen in cephalopods, some scientists believe.
That also may account for the dizzying diversity of squid-kind. There are more than 300 species, ranging from thumbnail-sized pygmy squid to the giant squid, which can grow more than 40 feet long -— and yet still manages to be one of the most elusive creatures on the planet.
Speaking of elusiveness…
2. They can ghost on you at any moment.
Not having a good time at the party? Wish you could just disappear without anyone being the wiser?
If only you had a squid's gift for ghosting. Then you would simply drop a smoke bomb on the dance floor — or as in the squid's case, an inky expulsion called a pseudomorph. The ink is designed to appear in the same shape and size of the squid.
In your case, people at the party would still see you standing there bobbing your head and pretending to have a good time. But the real you would be chilling and Netflixing at home.
Of course, squid deploy their inky doppelgangers to confuse predators and escape certain death. Appropriately, it shoots out of the creature's backside — pressed from a special posterior sac and mixed with a jet of water — to create the ultimate high-tail-it maneuver.
On second thought, you probably don't want to try this at a party.
3. They are the great communicators of the sea.
For all the time squid spend interfacing with other citizens of the sea, those tentacles may as well be fibre-optic cables. They're constantly sending signals. Like for example, when they're looking for a mate. Or not in the mood at all.
"When reef squid are mating, they are able to signal to their mate that they like them effectively, and at the same time, signal to other males that they basically are aggressive and to not come at them," Sarah McAnulty, a squid biologist at the University of Connecticut, tells WBUR's Here and Now.
4. No one adopts more quickly to a changing world than squid.
As times get tough for all life on this planet, squid just get going. The world's oceans have been undergoing a staggering transformation — from extended marine heat waves that raze coral and devastate ecosystems to the sheer amount of toxic trash being dumped into them.
And while climate change has set many ocean species on a slippery slope to extinction, this marine mastermind manages to thrive. A 2016 study found squid, like other cephalopods, faring so well in the new marine order that their populations are booming.
"Cephalopods are notoriously variable, and population abundance can fluctuate wildly, both within and among species," Zoë Doubleday of the University of Adelaide notes in a press release. "The fact that we observed consistent, long-term increases in three diverse groups of cephalopods, which inhabit everything from rock pools to open oceans, is remarkable."
That may have something to do with those previously mentioned gene-editing skills. Being able to adapt to an ever-changing environment is an essential survival skill. And squid do it like no other.
Trawling the deep, dark ocean depths and need a light? Squid have simply evolved bioluminescent light-producing organs.
Getting harder to find a meal in the dead oceans? Squid simply eat bigger and faster prey — with help from arms that are literally attached to its face.
It seems no matter what this planet throws at them, squid have an answer.
"They diverged in evolution so long ago from us," biologist Sarah McAnulty adds for Here and Now. "But they're basically the most advanced, behaviorally, animals of their kind of lineage."