The flight of the microscopic sea snail
Engineers and biologists in the US have discovered that a tiny sea snail swims using the same sort of movements that allow winged insects to take to the air.
The so-called "sea butterfly" has wing-like appendages where a snail's foot would normally be, and swims by flapping them in a characteristic figure-of-eight pattern, just like a fly or a bee.
Scientists say this insect-like swimming is a remarkable example of convergent evolution, and a particular surprise because most of the snail's cousins, among the ocean's zooplankton, swim using their appendages as paddles - not wings.
Their research appears in the Journal of Experimental Biology.
18 Feb 2016