Meeting Abstract
Many species of fish use suction, generated by the rapid expansion of the mouth cavity, to capture prey. The force and speed of such suction events require considerable power, but the amount of power produced varies between strikes. Over a dozen cranial skeletal elements move during the expansion of the mouth cavity, but the motion of no single element can act as a proxy for power production. Instead, looking collectively at skeletal movements may indicate that motion coordination acts as a proxy for power production. While it is known that patterns of coordination vary across different behaviors, such as suction feeding and prey processing, we predict that patterns of coordination will also vary within the same behavior, specifically suction feeding strikes that differ in the power production. We tested whether coordination was correlated to strike power by using X-Ray Reconstruction of Moving Morphology (XROMM) to create 3D animations of the cranial skeleton of a royal knifefish (Chitala blanci) during suction feeding strikes. Knifefish are a fitting species to examine this question because of their highly kinetic skulls and dramatic suction feeding strikes. We estimated instantaneous power by using a dynamic endocast of the mouth cavity to measure the rate of volume change and combining this with intraoral pressure measurements. We calculated patterns of motion coordination by cross-correlating the relative motion of different skeletal elements and compared them among strikes of different power outputs. Examining the relationship between skeletal coordination and suction expansion power will allow us to better understand how the musculoskeletal system controls feeding kinematics.
