a, b, Measured metabolic rates (μmol g−1 h−1) (a) and critical O2 pressures (Pcrit) (b) versus temperature (°C) in published laboratory experiments (circles). For clarity, metabolic rates are shown only for the subset of species with Pcrit data. c, Location data from OBIS for all species with Pcrit measured at multiple temperatures, yielding calibrated Metabolic Index parameters. The number of species with occurrences in the Pacific, Atlantic and Indian Oceans are labelled. Maps of the occurrences of individual species are available at https://obis.org/.