Meeting Abstract
Locomotion and feeding are key axes of diversity among fishes, and these are commonly integrated for successful prey capture. Consequently, aspects of predator-prey interactions are likely key drivers of decreased fitness of hybrids and migrants in divergent populations, ultimately playing a large role in ecological speciation. However, little is known about biomechanical variation among highly divergent populations of fishes, or how hybrids function in relation to the original populations. Threespine stickleback, Gasterosteus aculeatus, is an ideal species for teasing apart the intricate relationships between ecology, form, and function given the numerous independent invasions of freshwater lakes and streams from a marine ancestor. These natural replicates afford the opportunity to isolate convergence and many-to-one mapping of form to function. We investigated the differences in suction feeding kinematics and ram speed in 30 individuals from the west coast of British Columbia spanning freshwater, marine, and hybrid (marine x freshwater) individuals. This included both wild-caught fish and lab crosses. Feeding sequences were obtained using a high-speed camera (500 fps), and micro CT was used to link differences in kinematics with three-dimensional geometric morphometrics. From this, we can determine if there is concordance or a mismatch between morphology and biomechanics. Finally, we discuss the importance of these data for informing patterns of reproductive isolation and ecological speciation.
