The elasmobranch fishes include the living sharks, skates and rays that are important members of nearly all marine ecosystems. Their large size, secretive behavior, and wide-ranging habits make them difficult to observe in the field or to maintain in captivity. Consequently, little is known about their natural behavior and how it is mediated by their sensory systems. This volume is dedicated to the scientific contributions and memory of Donald Nelson, a pioneer in the study of shark behavior, sensory biology, and remote instrumentation. The two opening papers review Don Nelson's unique...