Researchers analyzed metabolic rate data from 25 fish studies to determine how fish metabolism scales with body size, finding strong evidence for a scaling coefficient of 0.89 rather than the commonly assumed values of 0.67, 0.75, or 1.0. The researchers curated data from 25 studies measuring standard metabolic rate, temperature, and mass across 55 independent trials and 16 fish species, then used flexible random effects models and information theory-based model selection to quantify the relationship. Strong evidence for a metabolic scaling coefficient of 0.89 with ΔSIC interval spanning 0.82 to 0.99. Mechanistically derived coefficients of 0.67, 0.75, and 1.0 are not supported by the data. Model selection supports random intercepts and random slopes by species, indicating other factors like taxonomy or lifestyle affect the relationship. Metabolic rates vary 2-3 fold across individuals of the same population and this variation is repeatable. The research is important for linking species physiology to projections of population abundance and predicting the impacts of climate change on species distributions. The metabolic scaling relationship is used as a cornerstone of metabolic theory of ecology to connect individual physiology to community patterns and energy flows across landscapes.
Citation
Jerde, Christopher L.; Kraskura, Krista; Eliason, Erika J.; Csik, Samantha R.; Stier, Adrian C.; Taper, Mark L. (2019). Strong Evidence for an Intraspecific Metabolic Scaling Coefficient Near 0.89 in Fish. Frontiers in Physiology.
"The research is important for linking species physiology to projections of population abundance and predicting the impacts of climate change on species distributions."
This paper is Open Access.
How metabolism scales with body size
Bigger fish use more energy, but not in direct proportion to their size. This study pooled 1456 measurements and found the exponent within a species is near 0.89, steeper than the classic 0.75 rule. Drag the slider to compare how much energy a larger fish needs under each rule.
Exponents from Jerde et al. (2019), Frontiers in Physiology: 0.89 estimated across 1456 observations in 55 trials, compared with the 0.75 and 1 hypotheses the paper tested. Curves show metabolic rate relative to the smallest fish.
Cite this article
Jerde et al. (2019). Fish Metabolism Often Deviates From Simple Scaling Rules. Ocean Recoveries Lab. https://doi.org/10.3389/fphys.2019.01166
