Meeting Abstract

81.5  Friday, Jan. 7  The Effects of Intraspecific Competition on the Prey-Capture Kinematics and Behavior of Bluegill Sunfish, Lepomis macrochirus PFEIFFENBERGER, J.A.*; MOTTA, P.J.; University of South Florida; University of South Florida jpfeiffenber2009@my.fit.edu

Previous studies on the prey capture kinematics and behavior in bony fishes have shown that temperature and satiation can affect prey capture behavior and kinematics. The densities at which bony fish are kept have also been shown to affect their growth, behavior, prey selection, feeding, and physiology. We investigated how density induced intraspecific competition for food affects the prey capture kinematics of juvenile bluegill sunfish, Lepomis macrochirus. High speed video was utilized to film five individuals feeding at three different densities representing different levels of intraspecific competition. We hypothesized that: (1) the feeding kinematics will be faster at higher levels of competition compared to lower levels of competition, and (2) when comparing the distance the predator and prey move between bluegill feeding at low competition levels to high competition levels, fish should shift from more suction-based feeding towards more ram-based feeding in order to outcompete conspecifics for a prey item. We found that, with increased intraspecific competition, prey capture became faster, involving more rapid jaw opening, shorter mouth closing times, and shorter gape cycles. Furthermore, the attack velocity of the fish increased with increasing competition however a shift towards more ram-feeding was not confirmed, although with increasing competition the bluegill apparently used less suction. Our study demonstrates that prey capture kinematics are affected by the presence of conspecifics and that future studies need to consider the effects of competition on prey capture kinematics.