Mantle cylindro-conical, narrowing behind, rather wide in larvae and adults, very narrow in juveniles. Head not retractable. Fin broadly diamond-shaped, with very slightly tapering end. Fin width 2/3-3/4 ML. Arm ends not tapering. Ventral protective membranes on 3rd arms widened, in adult females form a wide triangular lobe. Tentacles rather short and narrow. Rings of large club suckers with 4 long teeth located crosswise, others smaller. Fixing apparatus with knobs and suckers; 4-7 small dentate suckers proximal to first knob on tentacular stem. Funnel pit with foveola, longitudinal ridges, and side pockets. Funnel and mantle cartilages never fused together.
Many small photophores dispersed under skin of mantle, head, and 4th arms. No dorsal, eyeball, or gut photophores. A silvery, reflecting, cigar-like stripe along ventral mantle from anterior part to anterior fin margin, wide dark stripe bordered by thin reddish ones along dorsal midline. ML up to 86 cm in the N Atlantic, to 65 cm in the S Atlantic.
Larvae: proboscis rather long, thin, 1/2-2/3 ML, may be equal to ML in early larvae, usually longer than arms. Lateral suckers on tip noticeably (up to 2 times) larger than others. Proboscis beginning to split at ML approx. 5 mm, finishing at 7-9. Third and 4th arm pairs developed at ML approx. 1.5 and 2.5-3 mm, respectively. Mantle in larvae barrel-shaped, in juveniles very narrow, cylindrical, pencil-like. Head not retractable into mantle. Mantle in larvae with dispersed large brown chromatophores, in juveniles with crimson and brown chromatophores.
Only species with disjunct bi-subtropical range: North and South Pacific, North and South Atlantic (in the latter from 13-14°S to 50-55°S in the SW and to 35°S in the SE Atlantic), and Southern Indian Ocean. A very common species, subject to strong commercial exploitation in the N Pacific.