Abstract
SUMMARY: 1. There is a strong negative correlation between body mass and population density for 192 species from the zoobenthos of Mirror Lake, a small, oligotrophic lake. This correlation spans seven—nine orders of magnitude in body mass.2. The slopes of both the regression and the upper bound on the distribution of data points are significantly shallower than ‐0.75, the slope that has been suggested to imply that metabolic constraints limit animal abundance.3. The regressions for individual taxonomic groups (i.e. classes, phyla) do not conform closely to the overall regression line.4. It is suggested that metabolic constraints on community structure need not be expressed by a slope of ‐0.75 for regressions (or upper bounds) on body mass—abundance functions.