Vampyromorphida

Vampyromorphida is an order of cephalopods within the subclass Coleoidea. It includes the living family Vampyroteuthidae, represented today by the single species Vampyroteuthis infernalis, the vampire squid, and numerous extinct genera known from the fossil record. The group is defined by a mix of octopod-like and squid-like features and is considered a relict lineage with a substantial fossil record.

Morphology and adaptations: Members of Vampyromorphida have eight arms connected by a continuous web, and in the living vampire squid two small fins lie on the mantle. They lack the long, prey-catching tentacles typical of many squids. The arms bear hooks and cirri, and the body is gelatinous and often pale or translucent. Vampyromorphids possess photophores and can emit a bioluminescent mucus as a defensive strategy, a trait associated with deep-sea life.

Distribution, habitat, and diet: Vampyromorphids inhabit deep-sea environments, frequently in low-oxygen zones, where light is minimal. The vampire squid is slow-moving and uses its webbed arms to coil around itself when threatened. Its diet is largely detrital and particulate organic matter—marine snow—and occasionally small invertebrates, reflecting adaptations to food-limited deep-sea habitats.

Evolution and fossil record: The order has a rich fossil record that documents a broader past distribution and diversity. The living vampire squid represents a survival of an ancient lineage, and vampyromorphids are often discussed as a distinct branch near other coleoid cephalopods, illustrating early experiments in cephalopod body plans.