Meeting Abstract
Prey capture in fishes spans a continuum between ram- and suction-feeding. Ram feeders approach their prey at high speeds, snapping the jaw shut to secure their meal, whereas suction feeders rapidly expand the buccal cavity, forcing their food and the water around it into the mouth. An organisms’ ability to be successful in prey capture in the wild is determined partially by jaw-closing force and jaw-closing velocity; these organismal metrics are in turn directly limited by muscle performance, such as the physiological limits of muscle’s instantaneous length and shortening velocity. We empirically tested the interplay of jaw-closing velocity, force, and gape angle across five Centrarchid species that represent multiple points on the ram-suction spectrum. We found that ram-feeding fishes (largemouth bass and green sunfish) have faster jaw-closing muscles at a given force, and faster muscles overall than suction feeders (bluegills, redear sunfish). Preliminary analyses of the CT data for these species indicate that ram feeders have lower mechanical leverage (i.e. faster skeletal leverage) for jaw adduction than suction feeders. We are now developing a model to predict length-tension and force-velocity physiology using CT and diceCT data for all 47 species of the family Centrarchidae. Our goal is to examine the musculoskeletal anatomy and evolution of the jaw closing system across this iconic group.
