Meeting Abstract

75.4  Sunday, Jan. 6  Theoretical calculations of bite force in the great barracuda,(Sphyraena barracuda) during ontogeny HABEGGER, M.L*; MOTTA, P; HUBER, D; University of South Florida; University of South Florida; University of Tampa mhabegge@mail.usf.edu

The great barracuda Sphyraena barracuda is one of the most abundant predators among coral reefs and seagrass habitats. Both voracity and high-speed ram feeding are hallmarks of the prey capture methodology for this species. Although its robust jaws and sharp, needle-like teeth are remarkable physical features, little is known regarding the biomechanics of its feeding mechanism. The goal of this study was to describe the functional morphology of the jaw apparatus and investigate ontogenetic changes in bite performance of S.barracuda. The anatomy of the adductor mandibulae complex, responsible for the adduction of the lower jaw, was described. From these measures the jaw-adducting mechanical advantage and theoretical bite force of S.barracuda were calculated for an ontogenetic series of twenty individuals using a three dimensional static equilibrium model. Values of theoretical bite force ranged from 56 to 209 N at the corner of the jaw and from 26 to 83 N at the most anterior tooth in a range of body sizes of 75 to 122 cm total length. Bite force scaled with positive allometry at the corner and the tip of the jaw, indicating that bigger individuals have relatively higher bite force. The presence of positive allometry in the mechanical advantage and in one of the adductor mandibulae subdivisions (A3) are supportive data for these results. Bite performance is discussed with regard to prey consumption in S.barracuda, and together with an understanding of tooth function may provide some insight into the success of this species as a top predator.