Weekly Seminar: Fall 2012
Speaker: David W. Murphy (MechE | Johns Hopkins University)
Title: “Sensing and Swimming: The Hydrodynamics of Zooplankton Behavior”
Date: Friday, November 9, 2012
Time: 11:00 a.m.
Location: Gilman Hall 50 (Marjorie M. Fisher Hall)
The fluid flow surrounding zooplankton such as copepods, sea butterflies, and krill delivers chemical and mechanical information that indicates the presence of food, danger, and mates. Information transfer is bi-directional, however, and zooplankton motion also generates signals that are carried to prey, predators, and potential mates. An understanding of zooplankton behavior must incorporate both knowledge of the flow produced by these animals and the flow to which they respond. Furthermore, both viscous and inertial effects are important in the low Reynolds number flow regime in which zooplankton live, leading to interesting, non-intuitive flow phenomena. Using a high-speed tomographic particle image velocimetry (PIV) system designed to acquire volumetric velocity fields around free-swimming zooplankton, we explore aspects of swimming, sensing, and escaping in copepods and Antarctic krill.
David W. Murphy earned a Ph.D. in Civil Engineering from the Georgia Institute of Technology in 2012. He previously received an M.S. in Mechanical Engineering from Georgia Tech and an M.Phil. in Biological Science from Cambridge University. His research interests lie at the interface of biology and fluid dynamics where he has studied zooplankton hydrodynamics (Ph.D.), cardiovascular fluid mechanics (M.S.), and insect flight aerodynamics (M.Phil.). David currently serves as a postdoctoral fellow with Professor Joseph Katz at the Johns Hopkins University, where he is investigating oil spill dispersion and interaction with marine organisms.