One genus in the World Ocean. Mantle conical, head usually much wider than mantle. Fins small, round, located on mantle end, joined. Left eye usually much larger than the right. Arms long, conical, with 2 rows of suckers, in some species joined by web near bases from outer and/or inner side. Tentacles very long, club with 4-8 rows of suckers commonly of strongly unequal size. Fixing apparatus long, consisting of knobs and suckers. Buccal membrane with 6 or 7 lappets, connectives to 4th arms attached dorsally. Funnel cartilage straight, slightly curved and widened caudally. Gladius with thin rachis and wide vane, without end conus. Photophores very numerous, large, with different and complicated structure, covering ventral (rarely also dorsal) side of mantle, head, and arms; only fins and tentacles are devoid of photophores; also lacking on eyeball and inside mantle cavity. The only genus, Histioteuthis, is represented in the South Atlantic by 9 species.
Planctonic stages recorded for: