Like other squid, Sthenoteuthis pteropus is bilaterally symmetrical and has a head with a pair of eyes, eight arms and two tentacles and a fleshy, muscular body known as the mantle.

The phenomenon has been little studied because it happens so rarely and so unexpectedly, but it has been photographed on a small number of occasions, and Sthenoteuthis pteropus has sometimes tentatively been identified.

The squid seems to be engaging in an active flying process rather than a passive glide as the fin is spread widely and the arms are held in such a position as might help provide lift.

[5][6] The squid were found to travel five times as fast in air as in water and it is thought that the behaviour may occur during long distance migrations in order to conserve energy.

In mature individuals, spawning takes place intermittently, up to a million ripe eggs with a diameter of about 0.8 mm (0.03 in) being present in the ovaries at any one time as well as a large number of immature oocytes.