Squids utilize a unique combination of jet propulsion and fin activity to move. Having filled its mantle cavity with seawater, the squid contracts its muscular mantle to send water out of its siphon. The siphon is highly flexible - it can point in any direction and contract independently of the mantle. The fins move synchronously or independently to provide thrust and lift by either undulating or beating. Squids are highly maneuverable animals. They can reach speeds of at least 8 m/s, swim in any direction, brake suddenly, hover in place, make agile turns, and produce countless other motions.
All of these movements comprise a vast locomotive repertoire that underlies essential behaviors such as migration, foraging, escape, and reproduction. Although locomotion has been studied in squids since the 1960's, our knowledge is limited to loliginid squid species. These coastal species are typically smaller but more easily caught and kept in captivity than their pelagic counterparts, the ommastrephid squids, whose lives remain poorly understood. However, ommastrephid squids are large enough for attaching tags and video packages onto their bodies. With increasingly better sensor technology, we are beginning to understand where these pelagic squid species go, how they swim, and what they do in the wild.