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| Vorticity plot derived from instantaneous 2-dimensional plots of the flow field. Click on plot to reveal a trailing wake of clockwise vortices shed from the edge of the pectoral fin. Arrows in this animation represent flow directions, whereas the color spectrum represents vorticity magnitude and direction, with clockwise being at the blue end of spectrum and counter-clockwise at the red end of the spectrum. |
Much of our information on lateral line function in the mottled sculpin and other species comes from studies done in still-water conditions. Yet many fish inhabit streams and lakes with significant ambient water motion. In this line of research, we are investigating various flow-related behaviors (e.g. rheotaxis and station holding), the ability of fish to detect prey-like signals in the presence of background flow noise, and how ambient flows may be altered by the fish’s own body. In collaboration with Erik Andersen and Mark Grosenbaugh in the Department of Applied Ocean Physics and Engineering at Woods Hole Oceanographic Institute, we have been using digital particle image velocimetry to visualize 2-dimensional sections of the flow field. In this demo, you will see how a slow (8 cm/s) uniform flow field is altered near the sculpin’s body by the huge pectoral fin, which helps the animal to hold station in the face of the downstream current.
