Westneat 9701345 This study will elucidate major evolutionary patterns in the functional morphology and hydrodynamics of locomotion in a diverse monophyletic group of reef fish: the triggerfishes and filefishes (Superfamily Balistoidea). Data on the fin morphology, 3-D stroke kinematics, and hydrodynamics of a taxonomically broad sample of these fish will be collected and analyzed within the framework of general mechanical predictions and tuo theoretical hydrodynamic models applicable to long-based paired fin propulsion. Objectives include: (1) assessing the strength of a widely assumed but untested correlation of fin shape and kinematic profile; (2) testing the theoretical advantages proposed for swimmers with long, narrow fins and deep, rigidly held bodies; (3) determining which of the two hydrodynamic models yields better estimates of mean thrust; and (4) examining predictions from simple lever mechanics and muscle architecture. The study, the first in aquatic locomotion to consider detailed form and kinematic data in a regorous phylogenetic framework, will narow the traditional gulf between functional studies that ignore the influence of common ancestry and evolutionary studies that fail to acknowledge biomechanical and hydrodynamic principles and contraints. The study will explore novel mechanisms of thrust with potential applications in underwater propulsion technology.
