Hibernation in freshwater turtles: softshell turtles (Apalone spinifera) are the most intolerant of anoxia among North American species

摘要: Softshell turtles (Apalone spinifera) were submerged at 3 °C in anoxic or normoxic water. Periodically, blood PO2, PCO2, pH, plasma [Cl−], [Na+], [K+], total Ca, Mg, lactate, glucose, and osmolality measured; hematocrit body mass determined; [HCO3 −] calculated. On day 14 of submergence, five eight softshell dead, one died immediately after removal, the remaining two showed no signs life other than a heartbeat. After 11 days submergence water, pH fell from 7.923 to 7.281 lactate increased 62.1 mM. Plasma was titrated 34.57 mM 4.53 mM. [Cl−] fell, but [K+] Ca Mg increased. In survived over 150 days accumulated. A respiratory alkalosis developed (pH-8.195, PCO2-5.49 10 days) early persisted throughout; variables changed submergence. are very capable extrapulmonary extraction O2, an anoxia-intolerant species turtle forcing them utilize hibernacula that unlikely become hypoxic (e.g., large lakes rivers).