Despite their microscopic size, many plankton undertake a daily migration that covers tens of meters in depth. As they journey, they must contend with currents, turbulence, and other flows that could knock them off-course. And, increasingly, research shows that a plankton’s shape makes a big difference in these flows.
Spherical plankton tend to cluster in areas of flow moving opposite to their direction of travel. But more elongated plankton can resist — or even reverse — this tendency, helping them stay on track. In turbulence, elongated swimmers are also better at keeping their thrust oriented in the desired direction of travel. So both nature and engineers should favor elongated microswimmers when contending with turbulence and potential crossflows. (Image credit: Picturepest/Flickr; research credit: R. Bearon and W. Durham)