SWIMMING IN STYLE: VISCOSITY DRIVES EUCHAETA NORVEGICA SPEED

Copepods are among the most abundant metazoans on Earth, dominating many marine zooplankton communities. Copepods range between 0.5 and 10 mm in prosome length, where the larger are found in higher latitudes and colder environments. As temperature decreases across latitudes, water density and viscosity increase. The relationship between these variables and the size and speed of an aquatic organism is best described by the Reynolds number, which measures the ratio between inertial and viscous forces. When copepods use their cephalic appendages to perform cruise swimming, they operate at low Reynolds numbers (1-10). This raises questions about the independent effects of viscosity on swimming behavior: is there an independent effect of viscosity on cruise style swimming? The beat frequency of Euchaeta norvegica performing cruise swimming was measured in waters with differing viscosities. Using polyvinylpyrrolidone (PVP-MW-360kD), a polymer that alters viscosity, we determine that as temperature decreases and viscosity increases, the beat frequency decreases. Our data indicates that changes in viscosity alone significantly affect the beat frequency and can explain 4%-23% of the changes in temperature.

Presentation Preference: Poster

Primary Presenter: Jayla Butler, Johns Hopkins University / Bigelow Laboratory for Ocean Science (jaylab020@gmail.com)

Authors:

Jayla Butler, Johns Hopkins University  (jbutle62@jh.edu)

Maura Niemisto, Bigelow Laboratory for Ocean Sciences  (mniemisto@bigelow.org)

Zachary Wagner, Bigelow Laboratory for Ocean Sciences  (zwagner@bigelow.org)

David Fields, Bigelow Laboratory for Ocean Sciences  (dfields@bigelow.org)