Vampyromorpha

(invertebrate zoology) An order of dibranchiate cephalopod mollusks represented by Vampyroteuthis infernalis, an inhabitant of the deeper waters of tropical and temperate seas.

An order of coleoid cephalopods that contains only one species, Vampyroteuthis infernalis. It is characterized by a flat, broad, leaflike, chitinous internal shell (gladius); eight arms around the mouth connected by a deep web; no tentacles, but two small sensory filaments that retract into pockets between the bases of the first and second arms; fingerlike cirri and a single row of suckers with chitinous rings along the arms; one pair of paddle-shaped fins on the body in adults (two pairs at the juvenile stage); very dark maroon, mostly black pigmentation; and photophores on the body, head, and arms. Vampyromorphs superficially resemble cirrate octopods, but they bear features that show distinct teuthoid (squid) relationships, and in many characteristics are intermediate between teuthoids and octopods.

Vampyroteuthis infernalis is a gelatinous bathypelagic (very deep, midwater living) species that inhabits worldwide tropical, subtropical, and temperate waters. It occurs mostly at depths of 1600–3800 ft (500–1200 m), occasionally to 4800 ft (150 m). See also Cephalopoda; Coleoidea; Octopoda.