Fig. 5. Critical oxygen partial pressure (P_c) for mass-specific CO₂ emission (_CO2) for early-stage (open boxes) and late-stage (hatched boxes) animals in each instar. The boundary of each box marks the 25th percentile and the 75th percentile. The line within each box indicates the median. Error bars mark the 10th and 90th percentiles. Asterisks indicate a significant difference between early- and late-stage animals.