An ontogenetic shift in the response of heart rates to temperature in the developing snapping turtle (Chelydra serpentina).

The affect of acute changes in temperature on heart rates was investigated for the first time in a developing reptile. Heart rates were determined early and late in incubation in snapping turtle (Chelydra serpentina) eggs. Late in incubation heart rates at any given temperature were lower than those observed early in incubation. The results of temperature switching experiments late in incubation were consistent with thermal acclimation.