Cephalopods, with their uncanny camouflage, writhing tentacles, and eerie intelligence, tend to take on a mystical quality in our stories and folklore. From the formidable giant squid in Twenty Thousand Leagues Under the Sea, to Paul the clairvoyant World Cup octopus, to Finding Dory’s color-shifting Hank, popular culture loves to paint our squishy undersea friends as crafty creatures with superhuman abilities. Whether our fascination is channeled into fear, admiration, or wide-eyed wonder, the secret to the appeal of cephalopods lies in their inherently ambiguous nature. While cephalopod intelligence and curiosity can at times feel remarkably human, their multiple grasping arms, versatile boneless bodies, and ominous underwater presence are as alien a vessel for intelligence as it gets (on this planet, anyway).
In some respects, our perception of cephalopods as aliens isn’t far off the mark. Evolutionarily speaking, human and cephalopod lineages diverged over 500 million years ago (to put this in perspective, the first dinosaurs hit the scene about 230 million years ago). On top of that, our tetrapod ancestors first crawled up out of the ocean nearly 400 million years ago. While some reptiles and mammals eventually decided to give salt water a second chance, humans have been knocking around up here ever since. Though the technologies of the last couple centuries have made the ocean more accessible to our landlubbing biology than ever before, it is still effectively an alien ecosystem. The “midnight” zone in particular, with its lack of sunlight, crushing pressure, and bizarre thermal vents, is famously more poorly explored and understood than the surface of the moon. And the biggest cephalopods of all, with eyes the size of dinner plates and giant hooked tentacles, are the ones who call midnight home.
Most squidgy undersea invertebrates recall a more simplistic time for animal life. Unassuming and passive, creatures like sea cucumbers, tube worms, and oysters have the look you’d expect from something that had climbed up out of the primordial soup, thought “this is far enough, thanks,” and hunkered down for the long haul. Cephalopods, on the other hand, developed complex nervous systems, arms that enable elaborate aquarium escape artistry, and, perhaps most unsettlingly of all, mammal-like eyes that have the audacity to stare right back at you. It is those big eyes, with their not-quite-right pupils, that beg the question, “How might an alien intelligence perceive the world? And, more importantly, how might it perceive us?”