As of 2004, this project is no longer current. Please see the Research Programs page for a list of current research projects.

The Role of Sensory Physiology and Behavior in the Remote Detection of Large Particles by Calanoid Copepods

Henry Vanderploeg

In the Great Lakes, copepods are the dominant grazers of phytoplankton and are important predators of ciliates and invertebrate larvae. Recent studies indicate that calanoid copepods are capable of discriminating between food particles that differ in nutritional quality. High-speed microcinematography has revealed that calanoids can detect the presence of particles as small as 5 and use coordinated actions of the mouthparts to capture them. It is not known, however, whether mechanoreception or chemoreception, or both sensory modes are used to detect and discriminate between particles. Because copepods are important mediators of trophic energy movement in the Great Lakes food web, understanding the influences of sensory physiology and behavior on their ability to feed selectively, and defining this selection accurately, is critical to understanding the impact of anthropogenic perturbations to aquatic food webs.

(currently no active research on this project)

1998 Accomplishments

We finished data analyses of high-resolution videos of freely swimming Diaptomus capturing inert 50-m polystyrene beads outside of the influence of the copepod feeding current. The beads were frequently more than half a body length away and were attacked after the "bow wake" of the moving copepod displaced the bead away from the copepod. To investigate the hypothesis deformation of streamlines around the copepod allowed its mechanosensors on the antennae to detect the bead, we constructed a physical model that showed this was possible. The observations and model support the hypothesis that large phytoplankton can be captured without chemoreception and they do not have to be within the feeding current to be detected. This project was completed in FY98.

This Project Ended 1998

Products

Bundy, M.H., T.F. Gross, H.A. Vanderploeg, and J.R. Strickler. 1998. Perception of inert particles by calanoid copepods: behavioral observations and a numerical model. J. Plankton Res. 20:2129-2152.

Last updated: 2004-04-24 mbl