The vampire squid is a small, soft, deep-sea cephalopod whose scientific name means "vampire squid from hell". It is neither a squid nor an octopus but the last survivor of an ancient group that split from both. It grows to about 12 inches (30 cm) including the arms, with a body of roughly 6 inches (15 cm), and is coloured velvety black to deep red.
Its eight arms are joined by a web of skin like a cloak, lined inside with soft spines and small light organs. Two long, thread-like filaments can be unreeled from pockets in the web and reach far beyond the body. Its blue eyes are about 1 inch (2.5 cm) across, the largest of any animal in proportion to its body.
Instead of ink, which would be useless in the dark, a vampire squid squirts a cloud of glowing blue mucus to confuse an attacker.
Vampire squid live in the deep sea of temperate and tropical oceans around the world, mostly between 2,000 and 3,000 feet (600-900 m). This is the oxygen minimum zone, where there is so little oxygen that most animals cannot survive. The vampire squid's slow metabolism and efficient blue blood let it live comfortably where few predators can follow.
For a long time people assumed the vampire squid was a hunter. In 2012 scientists at the Monterey Bay Aquarium Research Institute discovered that it actually eats marine snow: the drifting flakes of dead plankton, droppings and debris that sink from the sunlit waters above. It gathers this material on its sticky filaments, wipes them clean with its arms and rolls the food into a ball of mucus to swallow.
It is the only known cephalopod that does not catch live prey.
Vampire squid drift slowly through the dark with their filaments trailing, using very little energy. When threatened they turn their webbed arms inside out over the body, showing the spines and hiding the soft parts, a posture nicknamed the pineapple. The light organs at the arm tips glow and the animal can flash and dim to draw attention away from its body.
Unlike other cephalopods, which breed once and die, a female vampire squid appears to lay several batches of eggs over a long life, resting between them.
Vampyroteuthis infernalis is the only living member of the order Vampyromorphida, a lineage that was common in the oceans 300 million years ago. Its closest living relatives are the octopuses. The IUCN lists it as Least Concern: it lives too deep and is too scattered to be caught in numbers, although deep-sea trawling and the spread of low-oxygen water as the ocean warms could affect it in the future.
