Gelatinous Marine Snail: Tiny Marine Snails Fly in Water Like Winged Insects
"We looked at the wing kinematics – how it moves its wings in a figure eight pattern – and it's very similar to how a fruit fly beats its wings," Murphy told the Christian Science Monitor. "Then we measured the flow around the animal as it swims, and the sea butterfly uses one of the same tricks to generate extra lift that lots of tiny insects use. In this trick, called the 'clap and fling,' the animal claps its wings behind it and then flings them apart, sucking flow in between the wings. This creates tiny flow tornadoes, or vortices, at each wing tip, which helps to lift the animal.
This came as somewhat of a surprise to researchers who were used to the movements of zooplankton that have similar wing-like appendages but use them as paddles to push through the water.