The physiological consequences of breath-hold diving in marine mammals: The Scholander legacy

Most of the physiological traits used by marine mammals to perform long and deep breath-hold dives were described in Scholander's seminal paper in 1940. Since then, several studies have provided an improved understanding of the mechanistic basis of the mammalian diving response (Scholander, 1940, 1963; Mottishaw et al., 1999; Fahlman et al., 2011), the aerobic dive limit (ADL) (Kooyman et al., 1980; Butler and Jones, 1997; Davis and Kanatous, 1999; Horning, 2012), and management of respiratory gases (Boutilier et al., 2001; Fahlman et al., 2008a; Hooker et al., 2009; Kvadsheim et al., 2012), but many questions remain. Some widely-accepted ideas actually lack experimental confirmation, and a variety of marine mammal species, potentially novel models for elucidating new diving adaptations, have not been adequately studied. The aim of this Frontiers Special Topic is to provide a synthesis of the current knowledge of the physiological responses that may explain the varied diving behavior of marine mammals. We strove to include contributions that challenge current ideas, and which propose new hypotheses, utilize new experimental approaches, and explore new model species.