In this chapter we will describe the species-specific swimming and movement patterns of tunas, billfishes, and large pelagic sharks derived from extensive data sets obtained using acoustic telemetry and electronic data-archiving tags. We then endeavor to interpret and explain these results based on our current understanding of species-specific physiological abilities (e.g., 437tolerances to hypoxia and rapid changes in ambient temperature) while integrating these ideas with other important ecological factors (e.g., prey movements and availability). Understanding the physiological ecology underlying the vertical and horizontal movement patterns of large pelagic fishes is, however, much more than a purely academic exercise. It has important implications for pelagic ecosystem models (e.g., Kitchell et al., 2006), population assessments (e.g., Maunder and Punt, 2004; Bigelow and Maunder, 2007) and ultimately effective fishery management (e.g., Young et al., 2006b).