Figure 3.

(a) Comparison of accumulative oxygen consumption for seven representative groups of snails pretreated as indicated (increasing line thickness represents in order, 42 days dry (N = 2), 7 days dry (N = 2), 2 days humid (N = 1) and 7 days humid (N = 2)). Rate was measured every 1 min from zero, between 3 and 12 h at 40°C. This shows constancy of rate during this period after initial heat induced deceleration, and the effects of humidity and aestivation period on rate. (b) Effect of pretreatment on respiratory rate (least squared mean ± 1 s.e.m; N = 8 for all 7 days treatments, and N = 6 for the 42 days and 2 days treatments). Rates were calculated by averaging 1 min recordings for between 4–8 h exposure at 30 (closed) or 40°C (open symbols). In 7 wet (7 days dry snails wetted before respirometry) and 42 dry, rates were determined only at 40°C. Different letters indicate significantly different means (p < 0.01, using Tukey HSD test and RMANOVA, Cochran C more than 0.42 for 30 and 40°C; independent t-tests were used in comparisons with 7 wet and 42 dry). Apparent activation energies (eV) for rates between 30°C and 40°C are shown in parenthesis.