title: Frogs and turtles: different ectotherm overwintering strategies.
abstract: The ability of frogs and turtles to overwinter and to survive hypoxia and anoxia has long been a topic of interest. While data remains scant, the emerging picture shows fundamentally different approaches to overwintering in these two groups of ectotherms. Frogs are far more limited by availability of oxygen than are turtles, even at near-freezing ambient temperatures. The reasons for this probably involve the vastly greater cutaneous permeability of the former. With their extreme tolerance of anoxia and profound suppression of metabolism, overwintering in turtles should not be viewed as simply prolonged diving but rather as ectotherm hibernation. Their incredible diving capabilities are merely a spin-off of a successful overwintering strategy. The following discussion reviews the major physiological mechanisms involved in the overwintering strategies of these two ectotherm groups.
mesh_terms: D000064:Acclimatization; D000818:Animals; D003080:Cold Temperature; D006801:Humans; D010101:Oxygen Consumption; D011898:Ranidae / Q000502:physiology*; D012621:Seasons; D012879:Skin Physiological Phenomena; D013045:Species Specificity; D014426:Turtles / Q000502:physiology*