Mantle tapering into short tail. Fin tongue-like in larvae, transverse-oval in juveniles, diamond-shaped with rounded angles in adults. Eyes in larvae on short wide stalks. Arms rather short, weak, their tips usually broken upon collection. Arms in larvae with suckers only, hooks appearing at ML approx. 2.5 mm. Suckers in adults only on very tips of arms. Tentacles in larvae long, thin, with bunch of rather large suckers on tip (8 in 2 rows), club reduced at ML approx. 12 mm, stems at 25 mm. One or two photophores on ventral mantle, anterior to body end; one elongate brown photophore on end of each arm; some poorly noticeable (except in live animals) photophores on head and in mantle cavity. No large unpaired photophore on ink sac. ML up to 30-50 cm. The commonest species in the South Atlantic is Octopoteuthis megaptera (Verrill, 1885).