Copepod escape behavior in non-turbulent and turbulent hydrodynamic regimes

Abstract

Copepods respond to velocity gradients in the ambient fluid generated by the move- ment of nearby predators. Escape behavior of several species in response to hydrodynamic stimuli has been analyzed under non-turbulent conditions; however, copepods normally experience a flow- ing or turbulent environment. Two neritic species (Paracalanus parvus and Temora turbinata) were exposed to a siphon-generated flow field under both non-turbulent and turbulent conditions. Defor- mation rates of 6.16 and 3.93 s -1 were required to elicit escape behavior in P. parvus and T. turbinata, respectively. Copepod jump distances in response to the siphon-generated flow field were >6.8 mm and were not significantly different under non-turbulent and turbulent conditions.