Most species of Grimpoteuthis are poorly known. They are somewhat less compressed in the anterior-posterior axis than are members of Opisthoteuthis and they generally have relatively larger fins. Species are closely associated with the deep-ocean floor and some species, at least, alternate between sitting on the ocean bottom and swimming above it while some others apear to be completely pelagic.

Diagnosis

Opisthoteuthids ...

• without enlarged sucker fields on arms of males.
• Areolae absent.
• Optic lobe circular in cross-section.
• One optic nerve bundle penetrates white body.
• Shell U-shaped or slightly W-shaped.
• Sucker aperature without tooth-like structures.