MELLARD, J.P.*; FIELDS, D.M.; BROWN, J.; WEISSBURG, M.J.; YEN, J.; Georgia Institute of Technology: Effects of Viscosity on Copepod Signal Detection

Copepods, an important member of most aquatic food webs, interact strongly with their physical fluid environment. To respond in an ecologically appropriate manner copepods use their sensory structures to identify fluid mechanical disturbances. Their behavior is the result of integrating available environmental information with survival dependant on their ability to differentiate among signals created by prey and predators. The sensitivity to these disturbances may be contingent on the physical properties of the surrounding fluid. In this study we examined the effects of temperature and viscosity of their fluid environment on the individual response of three copepods from the Euchaeta genus. Tethered individuals were subjected to a calibrated water jet and behavior was visualized using Schlieren optics. Each Euchaeta sp. exhibited at least two distinct behaviors, an escape response and a capture response each with a distinct threshold. Analyses of the escape and capture behavior of these pelagic carnivorous copepods are compared to examine the influence of differing physical regimes.