DOI: 10.5061/dryad.cnp5hqc99
title: Data from: Physiological mortality rates of planktonic ciliates

description: 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.
description: I used ISI Web of Science and Google Scholar to search for
 experiments that measured growth and mortality rates of ciliates as a
 function of prey concentration (i.e. numerical responses). The search
 terms were “growth (rate)” or “numerical response” in combination with
 “ciliate*” to search for numerical response experiments and “starvation”
 or “starved” in combination with “ciliate*” to search for mortality
 experiments. In addition, I searched the literature cited in these
 publications for further datasets. I considered only planktonic ciliates.
 When studies did not report all parameters of the NR curve, the data were
 extracted from figures with DataThief III or WebPlotDigitizer (Version
 4.6) and fitted with a modified Michaelis-Menten equation that included
 the threshold prey concentration (P’) as an additional parameter.
 Mortality rates obtained by ROD experiments used the δ<sub>max
 </sub>reported in the respective study or calculated
 δ<sub>max</sub> from the maximum rate of decline after
 digitizing the data from the original curves, as described above. The
 literature search yielded δ<sub>max</sub> reported from 41
 studies investigating 56 species or strains in 81 NR experiments and 19
 ROD experiments. The final dataset (n = 77) included 37 studies and 48
 species. I analyzed the dataset using the R Statistical Software using the
 packages lme4, lmerTest, AICcmodavg, and MuMIn.
description: Excel, R
description: # Physiological mortality rates of planktonic ciliates ## Description of
 the Data and file structure I used ISI Web of Science and Google Scholar
 to search for experiments that measured growth and mortality rates of
 ciliates as a function of prey concentration (i.e. numerical responses).
 The main dataset containing available experimental studies reporting
 ciliate species, experimental temperature, prey species, ciliate maximum
 growth rates, ciliate cell volumes, habitat of ciliate isolation, method
 of study and reported or calculated ciliate mortality rates are reported
 in the 'Dataset_v2.xlsx' file. This is the main document.
 Missing data codes: N.A. = not available; n/a = not applicable. More
 details about each column of the main document can be found in the
 'Units_table.xlsx' file. Details on the references - i.e.
 authors, publication year, title, journal/book, volume and page/article
 numbers - used to compile this dataset can be found in
 'References.xlsx'. ## Sharing/access Information The individual
 data were derived mainly from the ISI Web of Science. The data compilation
 is novel.