Fish Swimming and Flow Sensing
Mechanical and Aerospace Engineering
Department Seminar Series
4/9 (Thursday) Noon – 1:00 pm RH202
Fish Swimming and Flow Sensing
James C. Liao, Ph.D.
The Whitney Lab for Marine Bioscience
Department of Biology
University of Florida
St. Augustine, FL
The simple sinusoidal motions of fish swimming, while soothing to observe, mask complex interactions of muscle physiology, neural control and fluid dynamics. My research investigates how fish can exploit the energy in their environment when they swim in unsteady flows such as a Karman vortex street. In order to sense flow, fishes possess a unique lateral line system, which is composed of hair cell sensors (e.g. neuromasts) distributed over the body. Using larval zebrafish (Danio rerio), we performed electrophysiological recordings of lateral line neurons while mechanically deflecting individual neuromasts with a piezoelectric stimulator. This allowed us to isolate the physiology of the system from the hydrodynamics. We characterized the responses to ramp stimuli as well as sinusoidal and pulse stimuli. In order to better understand the hydrodynamics, we outfitted 3-D printed fish models with surgical-quality pressure sensors to monitor the pressure distributed over the body. Our findings advance the understanding of aquatic locomotion and sensing and have strong implications for inspiring the design of quiet and efficient autonomous underwater vehicles.
I am broadly interested in the mechanisms of animal behavior. Surprisingly, relatively little is known about how animals move so reliably in an unpredictable and complex physical world. For my Ph.D., I studied the biomechanics of fish swimming in the Department of Organismic and Evolutionary Biology at Harvard University. I then received a NIH postdoctoral fellowship to study in the Neurobiology Department at Cornell University to better understand how nerve cells are interconnected and function in fish. From there I started an assistant professorship at the Whitney Lab as part of the Biology Department at UF. I am also a Research Associate at both the Florida Museum and American Museum of Natural History in New York City. In my first year as a faculty member, I obtained funding from the NIH to investigate how fish sense water movements using a specialized hair cell system called the lateral line. This past summer, I obtained funding from the NSF to continue this research, which spans from understanding the energetics of freely swimming fishes to recording the response of single neurons to mechanical stimuli in transgenic zebrafish. I also maintain a strong interest in the diversity of fishes and natural behaviors in the field, making the Whitney Lab an ideal place to conduct these studies. This, in addition to our current projects, will comprise our exciting research efforts in the coming year. We hope that our work will advance a deeper understanding of how animals sense the environment and move, which can have wide ranging impacts from robotic vehicle and sensor design and fish conservation, to diagnosing healthy human hearing and balance.