Evolution of the Pharyngeal Jaw Apparatus in Ray-Finned Fishes

University Of California-Davis, Davis CA

Investigators

Abstract

The ecological and evolutionary success of bony fishes, the most speciose group of vertebrates, is associated with extensive diversity in feeding biology that is facilitated by versatile systems of prey capture and processing. This research will elucidate mechanisms of function in the pharyngeal jaw apparatus of ray-finned fishes, the primary device used in manipulating, chewing, and transporting prey during feeding. The pharyngeal jaw apparatus is a poorly understood, complex system of modified gill-arch muscles and bones that has underdone extensive modification during fish evolution. Using recordings of muscle activity and a new method for visualizing skeletal motion inside the skull, sonometric-ultrasound, this research will test models of pharyngeal jaw function in several major groups of fishes in order to establish the mechanisms of jaw action and its evolution within the largest group of living vertebrates. This research will address basic questions about how the muscle-skeleton linkage system of the pharyngeal jaw apparatus functions, and how it has been modified during evolution to produce novel function and diversity in feeding biology. The complexity and diversity of this system will provide the raw material for exposing general principles of neuromuscular evolution.