With their blood-red skin, white snapping beak and hooks arranged along their eight arms, the vampire squid is a spine-chilling apparition of the deep. Their scientific name, Vampyroteuthis infernalis, doesn’t help matters – the vampire squid from hell. But it’s a highly misleading name.
For one thing, they aren’t actually squid, but distant relatives of octopuses and squid, and the only living members of their family, the Vampyroteuthidae. And they’re not bloodsucking beasts from the underworld. They’re actually quite gentle and small – at most, their bodies grow to 30cm, roughly the size of a rugby ball.
For a long time, scientists had no idea what vampire squid eat, and generally assumed they were predators lurking in the dark waiting to leap on live prey. Then, in 2012, researchers from Monterey Bay Aquarium Research Institute in California made a breakthrough and published a study revealing that vampire squid have their own unique way of feeding.
A deep-diving robot equipped with video cameras was dispatched into the deep and beamed up images of a vampire hovering in the water column. It unfurled two long thin filaments, eight times the length of its body and used them to collect fluffy particles of organic matter, known as marine snow, which trickle down from above.
Marine snow is not nearly as nice as it sounds. It’s a mixture of dead plankton and their droppings, all stuck together with goo. Now and then, the vampire squid on camera reeled in its snow-covered filaments, wiped them over its arms, packed the marine snowflakes into little snowballs, then passed them to its mouth and swallowed. It turns out these are snow-eating squid.
Scavenging for falling particles is an excellent strategy for vampire squid, which live in the depths of the ocean where there’s little food around. There’s also not much oxygen to breathe.
They live between around 600 and 1,200m down, in a part of the deep sea known as the oxygen minimum zone. So, it makes perfect sense that vampire squid have evolved an energy-saving strategy. Rather than dashing around in search of prey, they can float in the water column and gently gather marine snow.
Like all animals living in the deep, vampire squid need to avoid becoming someone else’s dinner, and they have various tactics to avoid capture. When threatened by an attacker, they pull their arms over their heads and turn themselves inside out, so those fearsome looking spikes stick out in all directions. Scientists refer to this as the pineapple pose.
Vampire squid also have an ability that’s common among deep-sea species: they can light up their bodies. They have a glowing dot of bioluminescence at the end of each arm. It’s not entirely clear what function their lights serve, but perhaps they use them to startle attackers, flashing stars in front of a predator’s eyes. They can also release a cloud of glowing goo as a distraction, before making a quick escape into the dark.
Read more:
To submit your questions email us at questions@sciencefocus.com (don't forget to include your name and location)