Physiology of common map turtles (Graptemys geographica) hibernating in the Lamoille River, Vermont

• Published in: The Journal of experimental zoology 2000-02, Vol.286 (2), p.143-148
• Main Authors: Crocker, C.E., Graham, T.E., Ultsch, G.R., Jackson, D.C.
• Format: Article
• Language: English
• Subjects: Animals; Fresh Water; Hibernation - physiology; Turtles - physiology; Vermont
• ISSN: 0022-104X; 1097-010X
• DOI: 10.1002/(SICI)1097-010X(20000201)286:2<143::AID-JEZ6>3.0.CO;2-1

Common map turtles (Graptemys geographica) were collected from a natural underwater hibernaculum in Vermont at monthly intervals during the winter of 1997–1998. Blood was sampled by cardiac puncture and analyzed for pH, PCO2, PO2, and hematocrit; separated plasma was tested for Na+, K+, Cl–, total [Ca], total [Mg], [lactate], and osmolality (mOsm kg–1 H2O). Control (eupneic; 1°C) values for pH, PO2, PCO2, [HCO3–], and [lactate] were 7.98 ± 0.03, 47.4 ± 18.7, 10.1 ± 0.7 (mm Hg), 36.1 ± 0.2 (mmol liter–1), and 2.1 ± 0.1 (mmol liter–1), respectively. Between November 1997 and March 1998, ice covered the river and the turtles rested on the substratum, fully exposed to the water, and were apneic. Blood PO2 was maintained at less than 3 mm Hg (range 0.9 ± 0.2 to 2.1 ± 0.7 mm Hg), PCO2 decreased slightly, plasma [lactate] was