Which marine invertebrate is commonly called the vampire squid?

The vampire squid is a deep-sea marine invertebrate commonly called the vampire squid.

Despite its name and dark appearance, it is neither a true vampire nor a conventional predatory squid. It belongs to the cephalopod order Vampyromorphida and has characteristics linking squids and octopuses. Its scientific name, Vampyroteuthis infernalis, means roughly “vampire squid from hell.”

The animal usually lives in the oxygen-minimum zone, where oxygen levels are too low for many active predators. Rather than chasing large prey, it collects falling organic particles, mucus and small organisms with long filaments. When threatened, it can turn its webbed arms inside out and display photophores that produce blue light.

The vampire squid has eight arms plus two retractable filaments. It is often confused with bioluminescent squids, but its light-producing organs and feeding strategy are specialized for the deep ocean. Its large eyes help it detect faint light in its dark habitat.