Our lab is interested in the biomechanical and neural mechanisms of how animals interact with their environment. We use fishes as our experimental model because they provide several strong advantages. First, they makeup over half of all living vertebrates, thus providing access to enormous morphological and behavioral diversity. Second, they are the most basal vertebrates, so their organ systems are relatively simple and accessible compared to more derived vertebrates, such a mammals. Third, advances in zebrafish genetics allow us to use powerful in vivo techniques to monitor individual and population-level neuronal morphology and activity. Fourth, most larvae are transparent, enabling direct observation of cell-to-cell connectivity and activity, as well as behavioral studies involving ablation of specific neurons.

Our research seeks to uncover the mechanisms of ecologically relevant behaviors through the lens of biomechanics, engineering, neurobiology, physiology and evolution. Our philosophy is to ask questions from a sound understanding of the natural history of the organism, choose laboratory techniques to test questions in the most direct manner possible, and then see if our findings explain our observations of behavior in the natural environment.

Our lab has three current research topics.

1. Fish swimming in turbulence

We are interested in the mechanics, energetics and control of locomotor behaviors in natural flow conditions. Fishes routinely encounter turbulence in nature, such as when swimming behind a rock in a stream or when schooling. Turbulence is characterized by vortical flows that span a wide range of sizes and strengths and is difficult to study because of its chaotic nature. To simplify this task, our approach is to expose fish to the well-characterized, turbulent wakes of geometric objects in which we can systematically alter vortex size, spacing, and shedding frequency. We have found that under certain conditions swimming fish can exploit experimentally-generated vortices to decrease muscle activity. Current and future work expands upon our earlier work featured on the cover of Science and focuses on the mechanisms of vortex association in different fish species behind cylinders, flags and foils as well as exploring the material flexibility of the body that enables environmental vortex recapture.

2. Function and organization of the lateral line

Animals must accurately sense their environment in order to translate them into appropriate motor behaviors. Hair cells convert mechanical deflections into electrical signals to initiate a complex sensory pathway that provides the foundation for several sensory modalities in vertebrates, such as hearing and balance. In fishes, hair cells of the lateral line system enable the ability to sense water flow, or "distance touch," which is critical to predator evasion and prey capture. Afferent neurons directly contact hair cells and provide the first site of signal processing. Rapid progress has been made in understanding hair cell function, yet we still know relatively little about how information is subsequently processed by afferent neurons. Our lab takes advantage of optical, genetic and electrophysiological techniques to examine neuronal morphology, connectivity and activity in intact, behaving zebrafish. Our work explores the functional organization of lateral line afferent neurons with the ultimate goal of understanding how the ability to sense hydrodynamic signals can influence swimming performance.

3. Field studies of natural behavior

How do fishes behave in their natural environment? We are using our laboratory studies to make predictions about behaviors in the field. One exciting and applied aspect of this approach is the ability to contribute to issues in stream restoration and fish passageway. How do you design an optimum stream or fish ladder? Can the biomechanical and sensory limitations of organisms predict the behavioral ecology of species? This work allows us to ground truth our laboratory findings in an ecological context and provides inspiration for new projects.

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