HUSKEY, S.H.; Western Kentucky University: Modulation of prey-capture kinematics in largemouth bass, Micropterus spp.

The feeding behavior of a predator may be as important as it�s morphology in shaping patterns of prey-resource use. The ability to modulate these predatory behaviors based on the perceived type and location of prey likely leads to a species� trophic diversity and it�s ability to exist in variable environments. This study explored variation in prey-capture kinematics and degree of prey-capture modulation between Michigan and Florida Micropterus spp. An overlapping size class of bass from both locations was transported into the laboratory and filmed at 500 f/s while feeding on different prey in structured and non-structured environments. Michigan bass, M. salmoides, demonstrated very little modulation of pre-strike and/or prey-capture kinematics regardless of prey type (e.g. live shrimp vs. live fish) when feeding in the open water. Conversely, open water Florida bass, M. floridanus, modulated their pre-strike kinematics relative to prey type, striking faster at shrimp prey than at fish prey. Bass from both populations demonstrated significant modulation of pre-strike behaviors when feeding in open water vs. vegetation. Fish always accelerated when capturing prey in the open water; in contrast, they always decelerated when capturing prey in the vegetated environment. Key components of the prey-capture kinematics in largemouth bass were highly stereotypical and differed little between species, prey types, or locations. It is hypothesized that fish exposed to a diverse prey base during their life history have a greater ability to modulate their prey-capture behaviors relative to fish that occur in less diverse prey environments.