In situ observations on Brachioteuthis beanii Verrill: paired behaviour, probably mating (Cephalopoda, Oegopsida)

A behaviour that has never been seen in cephalopods was observed thre times in large aggregation of Brachioteuthis beanii Verrill, 1881. During a series of submersible dives off Cape Hatteras, North Carolina, estern U.S., three pairs of Brachioteuthis were seen, and one pair was video-taped. In all three pairs one squid grasped the other by the posterior mantle in its arm crown. This paired behaviour involved brief periods in which the grasped squid bent its head and body posteriorly and vigorously moved its arms around the head and mantle opening of the grasping squid. Although we were unable to capture any of the coupling pairs to determine their stage of maturity, we believe this unusual activity represents mating behaviour