Meeting Abstract
The freshwater northern pike Esox lucius and marine great barracuda Sphyraena barracuda are superficially similar in appearance and hunting behavior. Both possess elongate bodies with long pointed snouts and are ambush predators that utilize short bursts of high speeds to prey upon fishes throughout ontogeny. However, these fishes are in different orders (Esociformes and Perciformes, respectively) and last shared a common ancestor in the Triassic. The goals of this study were to describe the adductor mandibulae complex, calculate the theoretical bite force and mechanical advantage using a three-dimensional static equilibrium model, and examine the scaling of bite force in 27 E. lucius (9.2-83.8 cm TL). We then compared these measures to previously published data for S. barracuda. All measurements for E. lucius scaled with isometry, except for the in-lever which was negatively allometric. This is contrary to S. barracuda, where all measurements except the anterior out-lever were isometric. Posterior bite force for the largest pike was 44.0 N, compared to 63.8 N for the same sized barracuda. This is likely due to the differences in adductor anatomy. Despite the fact E. lucius have higher mechanical advantage, they lack an A1 and have a smaller A3 adductor division than barracuda. Pike have large, sharp, blade-like teeth on the posterior dentary, which may make high bite forces unnecessary.
