Figure 2. The relationship between the metabolic scaling slopeb and log10 metabolic level L within species of ectothermic vertebrates. Left panels show measurements in inactive animals of water- (A ) and air-breathing (B ) species, where lines join measurements made at different temperatures of single experiments in the same species. Right panels show values for animals under different activity levels of water- (C ) and air-breathing (D ) species, where lines join measurements made at a single temperature and species (temperature of treatments is indicated by colour). Inset plots show posterior kernel density estimates of the effect of log10 L on bL) for each group (water- or air-breathers), with means (dots) and 95% credible intervals (horizontal bars and shaded areas) from Bayesian models (see Table 1). Experimental temperature (T) is shown by a colour scale, and dashed horizontal lines indicate the typical metabolic scaling boundaries under the MLBH.