Data from: Physiological mortality rates of planktonic ciliates

Contrasting physiological mortality with predator-induced mortality is of
tremendous importance for the population dynamics of many organisms but is
difficult to assess. I performed a meta-analysis using planktonic ciliates
as model organisms to estimate the maximum physiological mortality rates
(δmax) across pelagic ecosystems in relation to environmental and biotic
factors. Data were compiled from published numerical response (NR)
experiments and experimentally determined rates of decline (ROD).
Variables reported are ciliate species and order, ciliate specific growth
rates (rmax), prey species, temperature, habitat (marine vs freshwater),
the coefficients of the numerical response experiments, and reported or
calculated ciliate mortality rates. The median δmax of planktonic ciliates
was 0.62 d−1 and did not differ between marine and freshwater species.
Maximum ciliate mortality rates were species-specific and affected by
their rmax, cell volume, and ability to encyst. Cyst-forming species had,
on average, higher δmax than species unable to encyst. Maximum mortality
rates of ciliates were positively related to rmax but appeared unaffected
by temperature. I conclude that (i) in the ocean, physiological mortality
is more critical for controlling ciliate population size than ciliate
losses imposed by microcrustacean predation, but (ii) in many lakes, the
opposite holds; (iii) cyst-formation is an effective ciliate trait to cope
with the high mortality of motile cells upon starvation. The lack of a
temperature effect on δmax deserves further study; if correct, planktonic
ciliates may take advantage of rising ocean and lake temperatures, with
important implications for the pelagic food web.