Predator-Prey Interactions

Predator-prey interactions play a central role in the behavior, ecology, and population biology of most taxa and are critical in community dynamics. For elasmobranchs, most studies focus only on their role as a predator. This is an important oversight, because most species are both predator and prey, at least for periods of their life. In this chapter, we place predator-prey interactions in the rich theoretical framework that has developed over the last several decades, from both a behavioral and a trophic perspective (but see Chapter 8 of this volume for a detailed consideration of elasmobranch diets). Rather than compiling an exhaustive list of predator-prey interactions, we develop a framework for these interactions and highlight relevant elasmobranch examples. Considerable progress has been made in our understanding of predator-prey interactions, including insights into the behavioral intricacies of these interactions, since the rst edition of Biology of Sharks and Their Relatives; however, there remains much work to do, especially in light of changes in elasmobranch population sizes (for a review, see Feretti et al., 2010) and a growing realization that elasmobranchs may play important roles as both apex and mesopredators in some situations (Feretti et al., 2010; Heithaus et al., 2008a, 2010). We hope that this chapter will stimulate further studies that will help answer unresolved issues in the behavior and ecology of elasmobranchs.