The “vampire squid from hell” holds genetic clues to how octopuses first evolved

For the first time, researchers have obtained the genome of the mystifying “vampire squid from hell” and provided unparalleled insight into the evolution of cephalopods. Scientifically termed Vampyroteuthis infernalis, this deep-sea creature is a little eight-armed wonder with cloak-like webbing and striking red or blue eyes. Its genome, which is larger than any cephalopod at over 11 billion DNA base pairs, is more than four times the size of the human genome. Analyses reveal that, though it has been classified as an octopus, the vampire squid retains the characteristics of its ancient, squid-like ancestors. These findings shed light on the evolutionary link between octopuses and squids and help scientists understand how modern cephalopods diversified into the extraordinary species seen today. The research also offers clues about deep-sea survival adaptations over millions.The vampire squid represents a very peculiar and special position within the family of cephalopods; despite having an octopus-like eight arms, its genetic material also shares considerable homology to squids and cuttlefish. This places the species in an intermediate lineage that bridges the evolutionary gap between octopuses and other cephalopods. Its genome retains fragments of DNA inherited from a common ancestor, in effect preserving a living record of the earliest stages of cephalopod evolution.In order to unlock these evolutionary secrets, researchers at the National Institute of Technology, Wakayama College, Japan, successfully sequenced the vampire squid's genome. The extraordinary 11 billion DNA base pairs are more than double the size of the largest known squid genome and over four times larger than the human genome. This has shown extensive genomic reorganization with duplications, rearrangements, and expansions of gene families, likely key in developing the remarkable diversity found among living cephalopods. Comparison of the vampire squid genome against those from other cephalopods, including pelagic octopus, can help researchers determine which traits are truly ancient, thus conserved, and which have evolved more recently.The unprecedented genomic insight into Vampyroteuthis infernalis' life has shown how it serves as a living bridge between major cephalopod lineages, offering a rare window into ancestral features from which both octopus and squid lineages diverged.Modern cephalopods diverged into two lineages: the Octopodiformes, which include eight-armed species like octopuses and the vampire squid; and the Decapodiformes, including squids and cuttlefish. The genome of the vampire squid sits at the interface of these lineages, confirming that their common ancestor was more squid-like than previously realized. Due to its ancient genomic features, it represents a rare window into how octopuses and their relatives emerged into the diverse and complex forms seen today. Analysing Vampyroteuthis infernalis allows scientists to trace evolutionary changes across millions of years. Its DNA has given an insight into how ancestral genome rearrangements have contributed to the unique adaptations of modern cephalopods, from intelligence and camouflage to their highly specialised body structures.Also Read | Rhinophis siruvaniensis: Rare shieldtail snake discovered in Kerala, non-venomous with striking features and unique characteristics