A "Vampire Squid from Hell" Just Opened the Door to the Ancient Origins of Octopuses
It may sound like something from a horror story, but the mysterious Vampyroteuthis infernalis – often called the "vampire squid from hell" – has just made scientific history. Researchers have decoded the creature's massive genome, revealing over 11 billion base pairs. To put that in perspective, that's more than double the size of the largest known squid genomes and several times bigger than those of any octopus. But here's where it gets truly fascinating: hidden within this enormous stretch of DNA lies an ancient evolutionary tale that reshapes how we think about cephalopods.
Although its eerie name suggests otherwise, the vampire squid isn’t an actual squid—or an octopus, for that matter. It represents a rare surviving branch of an ancient lineage that diverged hundreds of millions of years ago. In evolutionary terms, it’s a living time capsule—something scientists call a "living fossil." Tracing its ancestry back around 183 million years, this deep-sea dweller has stubbornly held onto many traits from its early relatives, adapting just enough to endure in the oxygen-starved darkness of the ocean’s depths.
But here's the part that sparks scientific debate: while it's classified as an octopodiform (a broad family including octopuses), its chromosomes suggest a stronger resemblance to its 10-armed cousins, the decapodiformes—a clue that might rewrite parts of cephalopod history.
When scientists analyzed its genome, they found that about 62 percent consisted of repetitive DNA—sequences that copy themselves endlessly, dramatically inflating genome size without adding new functional genes. Still, this repetition might not be meaningless; large portions of repetitive DNA can play subtle regulatory roles, influencing how genes behave. Could the vampire squid's "bloated" genome have helped it survive millennia of evolutionary upheaval? That’s still an open question.
To find out more, researchers at the University of Vienna, led by genomicists Oleg Simakov and Emese Tóth, compared the vampire squid’s genetic makeup to that of various other cephalopods, including squids, cuttlefishes, the shell-bearing Argonauta hians, and even the spiral-shelled nautilus. These comparisons revealed that modern octopuses and squids once shared a similar chromosomal structure, a kind of genetic blueprint connecting them to a mutual ancestor. Over time, octopuses underwent what scientists call "fusion-with-mixing"—a complex merging and compression of chromosomes that likely fueled their adaptability and intelligence.
The vampire squid, in contrast, seems to have opted for stability over change. While others evolved and diversified, it preserved much of the ancient genomic structure that existed before squids and octopuses split into separate evolutionary paths roughly 300 million years ago. That makes it a living key—a kind of evolutionary Rosetta Stone—allowing geneticists to decode how two vastly different creatures could spring from the same origin point.
Despite its fearsome nickname, this elusive deep-sea animal prefers to avoid conflict. It drifts silently in the oxygen-poor twilight zones of the ocean, more scavenger than predator, surviving in conditions that would be deadly to most forms of life. The specimen used for sequencing was unexpectedly caught as bycatch by Japan’s Tokai University vessel T/V Hokuto in Suruga Bay—a rare stroke of luck given how seldom humans encounter the species in the wild.
When compared side by side, the scale of its genome dwarfs those of its cousins: the longfin inshore squid carries about 4.4 gigabases, the Hawaiian bobtail squid 4.9, and the common cuttlefish 5.5. Meanwhile, octopuses lag far behind at around 2 to 3 gigabases. The discovery that the vampire squid’s genome ranges from 11 to 14 gigabases astonished the researchers—and raised new questions about why this creature carries such vast genetic material when simpler versions could theoretically suffice.
What we’re left with is an organism that bridges the past and present of cephalopod evolution. Whether it’s a relic refusing to change or a brilliant survivor that found perfection early on is up for debate. As genomicist Emese Tóth puts it, "The vampire squid preserves a genetic heritage older than both squids and octopuses. It gives us a direct view into the earliest beginnings of cephalopod evolution."
The study, now published in iScience, doesn’t just expand our understanding of one peculiar animal—it rewrites part of the evolutionary story of an entire group of some of Earth’s most intelligent and adaptable creatures.
And here’s a thought to leave you with: If the vampire squid has changed so little in 183 million years, does that make it a prisoner of its past—or proof that evolution sometimes knows when to stop improving? What’s your take—ancient perfection or evolutionary stagnation?
