(Bosc, 1802)
Mantle narrow, cylindrical, head not retractable. Fin diamond-shaped, not tapering behind, posterior margins straight. Second arms with some enlarged suckers. Ventral protective membranes on 3rd arms not widened. Club narrow. Rings of large club suckers with one long tooth in centre of distal side, others smaller; marginal suckers minute. Fixing apparatus with knobs and suckers. Funnel pit with foveola, longitudinal ridges, and usually side pockets. Funnel and mantle cartilages not fused.
Photophores: 1 each on ventral side of eyeball; 3 round patches near end, middle, and at base of 4th arms; 19 round patches on ventral mantle side distributed in alternating groups of two and four, caudalmost one not paired; many tiny simple photophores dispersed under skin of mantle; one in mantle cavity on gut at boundary between middle and posterior third of length. No dorsal photophore. ML up to 9 cm. Larvae: proboscis rather long, 1/2-3/4 ML, in early larvae longer, in late larvae shorter than arms; lateral suckers on tip up to 1.5 times larger than others. Proboscis beginning to split at ML approx. 3.5-4 mm, finished at approx. 6-6.5 mm. Fourth arm pair beginning to develop at ML approx. 3 mm. Mantle narrow. Larvae have only eyeball and gut photophores (at ML approx. 1.5 mm), luminous patches on mantle beginning to develop at ML approx. 9 mm, quite distinct at 15 mm. Single gut photophore and round luminous patches are characteristic features. Mantle in larvae with dispersed large brown chromatophores, in juveniles with crimson and brown chromatophores.
One bi-central oceanic species, known from the Atlantic and Pacific oceans but not reported from the Indian Ocean.