REESE,, S.A.*; CROCKER,, C.E.; JACKSON,, D.C; ULTSCH, G.R.: Physiology of overwintering in Chrysemys picta picta from Georgia
Eastern painted turtles (Chrysemys picta picta) from Georgia were submerged in anoxic and normoxic water at 3°C. Plasma PO2, PCO2, pH, [Na+], [Cl–], [K+], total Mg, total Ca, lactate, glucose, and osmolality were measured from turtles submerged for up to 150 days. Hematocrit and mass were determined, and plasma [HCO3–] was calculated. Turtles in normoxic water gained 17.5% mass and accumulated lactate (44.4 mmol/L) after 150 days of submergence. The increase in lactate was accompanied by a drop in pH from 7.955 to 7.748 and a fall in [HCO3–] from 40.7 mmol/L to 18.2 mmol/L. Anoxic turtles incurred a severe metabolic acidosis with a lactate of 155.3 mmol/L, a pH of 7.155, and a [HCO3–] of 5.37 mmol/L after 84 days of submergence. Although the measured responses to anoxic submergence were similar among turtles from Connecticut and Georgia, turtles from Georgia died 3-6 weeks earlier than the turtles from Connecticut, suggesting that some undetected stress was occurring, perhaps at the intracellular level.
