Many pelagic squid are able to launch themselves into the air using jets of water expelled through a funnel beneath their head. There are a number of photos online that show squid out of the water and holding their fins and tentacles in a gliding position. But it has been unclear whether the squid where using simple gliding, like a paper plane, or actively controlling the flight.
|The neon flying squid, Ommastrephes bartramii, holding its fins and tentacles for flight (photo Geoff Jones).|
Now researchers have taken photographic sequences for two schools of the neon flying squid, Ommastrephes bartramii, in flight. The sequences captured the entire flight process, from exiting the water to reentry. Their analysis of the photographs provides the first compelling evidence that flying squid are performing true biomechanical flight.
|Neon flying squid in flight with a red footed booby looking on (photo from Muramatsu et al. 2013)|
The researchers identified four phases of the flight; launching, jetting, gliding and diving. During the launch phase the squid's fins and tentacles are held in a streamlined position and the squid propels itself out of the water. The squid then spreads its fins and tentacles jetting through the air. Once the water within the mantle cavity is expended the squid continues to glide. Finally, the squid folds its fins and tentacles back into a streamlined position, changes is pitch and dives into the water with barely a splash.
|The phases of squid flight; a) launching, b) jetting, c) gliding and d) diving (from Muramatsu et al. 2013)|
Using birds within some images the researchers were able to estimate the length of the airborne squid and therefore their speed and distance covered. During the jetting phase the squid travelled at between 8.8 and 11.2 meters per second, which is about human sprinting speed. The squid covered up to 33.5 meters in flight, substantially less than a flying fish (~400 meters***), but better than previous estimates for flying squid (~10 meters).
*** Correction - While flying fish have been documented to travel over 400 meters in a single jump, their typical jumps are about 50 meters.