(Férussac and d'Orbigny, 1842)
Mantle rather wide, conical, in adults with short, soft tail. Fin tongue-like in larvae, very wide transverse-elliptical in juveniles, diamond-shaped, reaching anterior mantle margin in adults. Arms long and strong, with 2 rows of suckers in juveniles and hooks in adults. Tentacles robust, central part of club in larvae with 2 rows of suckers, in juveniles 2 rows of hooks (median) and 2 rows of very large suckers (marginal), and in adults only hooks (8-9 in a row), without suckers.
Photophores: the large ones not numerous, regularly arranged, the small very numerous. Twenty-two large hemispheric photophores in alternate groups of 4 and 2 on ventral side of mantle (4 groups of 4, and 3 groups of 2 photophores); 16 photophores on head (5 around each eye orbit at varying distances from it, 1 each near funnel and near base of 2nd and 4th arms); 20-30 large and small photophores along tentacular stem; one under skin near stem base; hundreds of small photophores on ventral sides of mantle, head, 4th arms, and dorsal sides of mantle and fins. No photophores on eyeball. Larvae and juveniles distinguishable by very wide, elliptical fin, photophores on tentacular stem (at ML approximately 7 mm), lacking on eyeball, and by characteristic pattern of large mantle and head photophores (from ML approx. 5-6 mm). Tentacular hooks developed at ML approximately 9 mm. ML up to 40 cm.