Note
The manned submersible Johnson Sea-Link II was used for a series of dives on the continental slope of the eastern Gulf of Mexico in September 1995. The deep-sea squids Mastigoteuthis hjorti Chun, 1913 and Octopoteuthis megaptera (Verrill, 1885) were repeatedly observed at depths of 600-850 m. Both species were videotaped alive, in situ, for the first time during these dives. These species share the characteristic of very large fins, almost as long as the mantle length, but their swimming behavior observed in the vicinity of the submersible differed greatly.