Fig 9.

Bacteria chasing phytoplankton. A bacterium (Pseudoalteromonas haloplanktis) (red) tracking a swimming phytoplankton cell (Pavlova lutheri) (cyan) is shown. Starting locations are shown by crosses within circles. The reversals in swimming direction enabled the bacterium to pursue the algal cell for many correct consecutive turns. Symbols on each trajectory are 0.04 s apart, and the total time is 2.2 s. (Adapted from reference 19 with permission. [Copyright 2002 Federation of European Microbiological Societies.] We acknowledge Greg Barbara for providing the cell positions used to redraw the original image in color.)