Adam, 1962
Mantle muscular, cylindrical in anterior, conical in posterior part, with long tail in adults. Fins transverse-oval in juveniles, heart-shaped with tapering end in adults; fin length in adults approx. 65%, width approx. 50% ML. Arms and tentacles long and strong. Club in juveniles with 9, in adults with 26-30 hooks; marginal suckers absent at ML >15 mm; 4-5 rows of suckers on dactylus. Surface of mantle, head and arms with flat tubercles of irregular form, smooth in early larvae. Gladius not visible from dorsal, with long cartilaginous rostrum posteriorly, triangular in transverse section, semi-translucent in juveniles; adult length 20-35% ML. No nuchal folds, no photophores. ML up to 75 cm.
Larvae and juveniles may be caught at night at the surface. At least 3 other species in the South Atlantic: Moroteuthis ingens (Smith, 1881) in Subantarctic and Antarctic areas, including the Patagonian shelf and slope, usually at the bottom; Moroteuthis knipovitchi Filippova, 1972, in the Antarctic to South Georgia; and Moroteuthis aequatorialis Thiele, 1920, supposedly tropical species of unclear taxonomic status.