Melissa Williams dives deep into a real vampire’s lair
Werewolves, ghouls and goblins – this season satiates our thirst for myths and legends of old. However, there is a real creature that deserves its Hallows’ Eve name. With the term being spun around banks and even the RSPB, it’s time to lift the veil on the vampire squid.
Quite literally translated as ‘vampire squid of Hell’, you may wonder how Vampyroteuthis infernalis can live up to such a title. Much like the gothic legends, this vampire is an ancient creature, with the species predating the dinosaurs. It’s a phylogenetic relic – a lone survivor of the order Vampyromorphida. Although evolutionarily distinct, it shares some characteristics with fellow cephalopods, which at first may confuse it with an octopus or squid.
Measuring only 30 cm in length and living in the depths of the tropical and temperate oceans, it may not appear particularly remarkable at first – but closer examination reveals its unique characteristics. Its 8 arms are webbed to form a deep red ‘cloak’ around its body. On its mantle a pair of locomotive fins protrude, not unlike elephant ears in appearance. Photophores in its skin allow it to change colour to become almost invisible in the dark water. Its eyes are the largest in the animal kingdom relative to its body size and can change colour from blue to red. Add to this its regenerative abilities, suckers, and pencil-like spines hidden beneath its cloak and you begin to appreciate its name.
In fact, these spines – or cirri – are harmless and, like most of its features, are defensive adaptations. When threatened, V. infernalis releases bioluminescent blue mucus from the tips of its arms, analogous to the ink sac of other cephalopods, to disorientate predators. Another novel defence involves turning its body inside out by lifting its webbed arms up over its mantle so that only its spiny cloak is visible. Then the creature uses bioluminescent photophores in the skin to make its arm tips glow blue. This change in appearance confuses predators and provides a distraction long enough for the vampire squid to swim away using propulsion and fin movements.
So why evolve these adaptations? Living at depths of up to 900 metres below sea level, oxygen concentration is low, so V. infernalis has modified its circulatory system to accommodate this. Haemocyanin carries oxygen around its body, giving the blood a distinctive blue colour. Even with this adaptation, the vampire squid has a very slow metabolism and so can’t maintain movement for long. It must therefore rely on defensive mechanisms and ambush feeding strategies for survival.
These feeding habits have remained shrouded in mystery until recently. In the deep ocean, living prey are few and far between, so the vampire squid mainly relies on dead crustaceans and faecal pellets for sustenance. If a living creature moves nearby, the vampire squid uses bioluminescence patterns to attract the prey closer. Its two retractable sensory filaments detect when an organism moves within range, and then it quickly engulfs the unsuspecting animal in its webbed arms, using cirri to subsequently move the food towards its beak-like jaws.
Clearly, of all animals, V. infernalis is worthy of the current holiday season. So this Halloween, forget mythical vampires and instead remember this enigmatic creature of the deep, and consider it a truly unique costume opportunity.
Featured image credit: Citron /