of arrival 1992.
Professor, tenured. B.A., Zoology,
The overall goal of my research is to test hypotheses about the relationships between morphology, function, and ecology in an evolutionary framework by adapting techniques from comparative functional morphology and biomechanics. My primary focus is on planktivorous fish that filter enormous volumes of water to retain food particles that are too small (~ 5 µm to 2 mm) to be sensed and engulfed individually. These filter-feeding fishes (e.g., anchovies, herring, and tilapia) belong to twelve orders and comprise at least 25% of the world fish catch. Although they have substantial impacts on plankton abundance and community structure, the methods that they use to extract small food particles from the water are unknown. By inserting a miniature fiberoptic endoscope and a thermistor flow probe into the mouths of freely-swimming fishes in the laboratory, I can visualize and measure flow near the gill rakers where particles have been assumed to be captured. The unexpected flow patterns recorded recently in three distantly-related filter-feeding fish species indicate that the rakers function as a crossflow filter. Although crossflow filtration is a multi-billion dollar industry for the manufacture of products that we use every day (e.g., dairy products, wine and beer, pharmaceuticals), this filtration mechanism had not been recognized previously in any vertebrate. The techniques used in my laboratory for flow visualization and measurement can be adapted to study the function of internal feeding structures in a diversity of animals, including filter-feeding birds and bivalves. My research program is expanding to include the study of mouthbrooding and larval feeding/locomotion in filter-feeding fishes.
Potential research projects include studies of fish feeding ecology and behavior, the design of physical models for food particle encounter and retention, and electron microscopy of oral structures.
College of William and Mary, Department of Biology