Chemotactic Maneuverability of Sperm
  In this fluid mechanics video, we explore the kinematics of chemotaxing sperm cells (sea urchin, \textit{Arbacia punctulata}) swimming in a chemoattractant gradient. We demonstrate that the complex swimming trajectories resulting in chemotactic behavior (`turn-and-run' motility) are comprised of several distinct flagellar maneuvers. These motility patterns likely play an important role optimizing chemotaxic motility and navigation, when the sperm cells are subjected external fluid flows. 
Jeffrey S. Guasto, Jeffrey A. Riffell, Richard K. Zimmer, and Roman   Stocker
physics.flu-dyn physics.bio-ph