Data from: Testing multiple drivers of the temperature-size rule with nonlinear temperature increase

The temperature-size rule (TSR) describes the inverse relationship between
organism size and environmental temperature in uni- and multicellular
species. Despite the TSR being widespread, the mechanisms for shrinking
body size with warming remain elusive. Here, we experimentally test three
hypotheses (differential development and growth [DDG], maintain aerobic
scope and regulate oxygen supply [MASROS] and the supply-demand hypothesis
[SD]) potentially  explaining the TSR using the aquatic protist
Colpidium striatum in three gradually changing and one constant
temperature environment crossed with three different nutrient levels. We
find that the constant and slowly warming environments show similar
responses in terms of population dynamics, whereas populations with linear
and fast warming quickly decline and  show a stronger
temperature-size response. Our analyses suggest that acclimation may have
played a role in observing these differences among treatments. The SD
hypothesis is most parsimonious with the data, however, neither the DDG
nor the MASROS hypothesis can be firmly dismissed. We conclude that the
TSR is driven by multiple ecological and acclimatory responses, hence
multicausal.