9314934 Yen Swarming of zooplankton at various temporal and spatial scales have been observed: where fist-sized ephemeral clouds of Acartia form in eddies behind coral heads or are found milling around shafts of light, to extensive layers existing at depth or migrating as deep-scattering layers. While aggregative behavior has been well-studied in larger aquatic organisms (fish, krill) and terrestrial animals (birds, insects), little is known of how copepods form aggregates nor how they maintain the patch against the tendency of spreading by random motion and the dispersive energy of mixing in the ocean. Furthermore, there is little quantitative knowledge of the cues that cause aggregations in zooplankton nor of the purpose of these aggregations. A detailed study of swarming behavior in copepods is needed yet this has not been done before because of limitations in making actual observations of swarming behavior or in monitoring situations where one can quantitatively evaluate their aggregative dynamics. This research project will observe and record zooplankton in a laboratory setting using laser-illuminated video imaging, and it will examine the kinematics of the formation and maintenance of zooplankton swarms to an attractive marker with a quantification of the 3-dimensional animal-animal interactions as well as the 3D animal-fluid motion. The project will determine the sensitivity of copepods to cues of different modalities (light-, odor-, motion- reception) which attract swarm members and to quantify the forces that maintain a swarm against dispersion by motion. The effects of attractant intensity and the species of the swarm member (stage, sex, size ) on swarm size, density and distribution (separation distance) as well as on swimming behavior (posture, orientation, turning and collision frequency, velocity and acceleration) will be investigated. To verify laboratory findings, the behavior of swarms and the dynamics of swarm formation in respo nse to a designated attractant will be examined in situ in nature. ***
