Kiorboe, T. Danish Institute for Fisheries Research,
Visser, A. Danish Institute for Fisheries Research,
Saiz, E. Institut de Ciencies del Mar, CSIC,

Pelagic copepods may remotely detect both predators and prey by means of hydrodynamic signals. We have developed a simple but general hydrodynamic model of the fluid disturbance generated by a moving plankter (or a plankter with a feeding current). Signal perception in copepods is due to the mechanical bending of setae, which requires a velocity difference between the copepod and the ambient water. Several components of a fluid disturbance (fluid velocity, vorticity, deformation, acceleration) may cause setal bending and, hence, elicit escape or attack reactions. However, the signal strengths due to these components have different magnitudes and attenuate differently. Considerations of this type lead directly to estimates of perception distances as functions of velocity and size of the predator or prey, as well as of the threshold signal strength. We have tested various predictions of the model with copepods in artificial hydrodynamic systems and found good agreement with theory; and we have estimated the magnitude of the threshold signal strength in various species. Further, we have applied the model and observed threshold signal strengths to predict the outcome of real predator-prey systems. Finally, the model is used to predict more fundamental properties of zooplankton predator-prey interactions and the implications on pelagic material fluxes in the ocean.
Day: Tuesday, Feb. 2
Time: 09:00 - 09:15am
Location: Hilton of Santa Fe
Code: SS02TU0900H