Fish alter locomotor and feeding kinematics to capture aerial prey

Although most fishes feed exclusively in water, some are capable of leaping into the air to capture flying, suspended or perched prey. Whereas some species specialize in aerial prey capture, others will only opportunistically feed aerially and lack any known morphological specializations that enhance their ability to do so. A key outstanding question is how non-specialist species overcome the challenges associated with aerial feeding, including the visual disruption at the air-water interface and the drastic differences in fluid density. Using largemouth bass (Micropterus salmoides), we addressed whether there are kinematic differences between aerial and aquatic feeding, and how generalist fishes modulate their kinematics to catch aerial prey at different heights. We quantified the three-dimensional kinematics of bass capturing mealworms aquatically and at a range of heights above the surface. Aerial feeding involved larger, faster cranial movements than aquatic prey capture. In addition, feeding events aimed at prey suspended higher were characterized by higher peak velocities and accelerations, as well as more propulsive tail strokes. Our results reveal how generalist fishes can feed in drastically disparate physical environments and will help us understand the evolution of aerial prey capture by examining exaptation to aerial feeding in primarily aquatic feeders.