Fig. 2. Mass-specific, aquatic (filled circles) and aerial (empty circles) O₂ consumption rates of Pseudis paradoxus tadpoles and froglets as a function of water O₂ tension (mean of initial P_O2 values), at 25°C. Each point represents a single animal, staged according to Cais after Gosner (Cais, 1982; Gosner, 1960) and individually measured. The data obtained from the animals in each group of stages are given separately. Lines through the data points represent significant correlations between the variables (broken line, aquatic; solid line, aerial consumption rates); detailed descriptions of correlation coefficients and statistics are given in the text.