REESE,, S.A.*; JACKSON, D.C.; ULTSCH, G.R.; Brown University, Providence, RI; University of Alabama, Tuscaloosa: Lactate Accumulation and Glycogen Depletion in Hatchling Turtles (Chrysemys picta bellii, Chelydra serpentina, and Graptemys geographica) Submerged at 3 ^oC

Newly hatched Chrysemys picta bellii, Graptemys geographica, and Chelydra serpentina were submerged at 3 ^oC in anoxic and normoxic water to investigate the ability of newly emerged turtles to overwinter underwater. Whole body homogenates were analyzed for [lactate], [glucose], and [glycogen]. Turtles of each species had similar [lactate] (0.04 mg/g, 0.05 mg/g, and 0.14 mg/g, respectively) and [glucose] (0.57 mg/g, 0.29 mg/g, and 0.33 mg/g, respectively) before submergence, but C. p. bellii had a [glycogen] of 18.7 mg/g while G. geographica had 12.2 mg/g and C. serpentina had 13.6 mg/g. Submergence in normoxic water caused a drop in [glycogen] to 13.0 mg/g (after 150 d), 6.3 mg/g (after 125 d), and 8.53 mg/g (after 150 d), respectively. Neither [lactate] nor [glucose] changed during normoxic submergence. Submerged in anoxic water, C. p. bellii survived 40 d, C. serpentina survived 30 d and G. geographica survived 15 d. [Lactate] increased to 6.67 mg/g in C. p. bellii, to 3.35 mg/g in G. geographica, and to 5.54 mg/g in C. serpentina; [glucose] also rose. [Glycogen] fell to 6.2 mg/g in C. p. bellii, to 7.3 mg/g in G. geographica, and to 4.8 mg/g in C. serpentina. These three species of turtle hatchlings appear to tolerate long-term submergence in normoxic water equally well. The reduced tolerance of these hatchlings (compared to adults of the same species) for anoxic submergence may be a factor in determining whether hatchlings spend their first winter in the nest or emerge and overwinter underwater.