The Sea Butterfly’s Underwater Flight

High-speed footage shows their insect moniker is apt.

Sea butterflies are graceful little snails that use their protruding bodies as wing-like lobes to “fly” through the water instead of as a foot to crawl along the ground. Scientists writing in the Journal of Experimental Biology captured the snails’ movement with four high-speed cameras and found they move their wings much the same way small insects would: namely, the figure-eight looking clap-and-fling mechanism. The researchers’ footage could help us better understand insect flight, which is hard to track because bugs flap their wings a blistering 200 beats per second. Sea butterflies’ wings beat at a more reasonable five beats per second.