Morphology of the jaw system in trichiurids: trade-offs between mouth closing and biting performance

In this study, we focus on two piscivore species of cutlassfishes (Trichiuridae) that show some degree of differences in morphology of the jaw system: Aphanopus carbo and Trichiurus lepturus. As studies dealing with myological features of A. carbo and T. lepturus are presently lacking, we first provide a detailed description of the head musculature of A. carbo and T. lepturus. Secondly, we focus on the mechanics of the mouth closing system of these trichiurids by using biomechanical modelling. More specifically, models allows us to: (1) describe the differences between how the lower jaw lever system works during mouth closure and during generating static bite force; (2) evaluate the effects of morphological change on the performance of both functions; (3) determine whether the configuration of each component of the lower jaw lever system is a compromise between both functions, or whether there is a partition of function (optimization for either hard biting or fast jaw closing) between the different parts of the jaw closing musculature; and (4) discuss the dynamical implications of having elongate jaws for capturing prey