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 Nelsons unique scientific accomplishments and provide insight into his strong bias towards study of animals in the field. These are followed by 14 scientific papers on elasmobranch behavior, sensory biology, and current monitoring technologies. The papers on elasmobranch sensory biology and behavior address questions on hearing, the lateral line, electroreception, the brain, orientation behavior, chemical irritants, feeding, and reproduction. The latter section of the volume presents papers on conventional tagging techniques, ultrasonic telemetry, physiological telemetry, remote monitoring techniques, archival tagging and satellite tagging. The intent of this volume is to familiarize both new and established scientists with the sensory biology and behavior of sharks and rays, and to encourage further behavioral research on these animals in their natural environment.