DOI: 10.5061/dryad.qjq2bvqrt
title: Impacts of selective predation on infection prevalence and host susceptibility

description: Predation can alter diverse ecological processes, including host–parasite
 interactions. Selective predation, whereby predators preferentially feed
 on certain prey types, can affect prey density and selective pressures.
 Studies on selective predation in infected populations have primarily
 focused on predators preferentially feeding on infected prey. However,
 there is substantial evidence that some predators preferentially consume
 uninfected individuals. Such different strategies of prey selectivity
 likely modulate host–parasite interactions, changing the fitness payoffs
 both for hosts and their parasites. Here we investigated the effects of
 different types of selective predation on infection dynamics and host
 evolution. We used a host–parasite system in the laboratory (Daphnia
 dentifera infected with the horizontally transmitted fungus, Metschnikowia
 bicuspidata) to artificially manipulate selective predation by removing
 infected, uninfected, or randomly selected prey over approximately 8–9
 overlapping generations. We collected weekly data on population
 demographics and host infection and measured susceptibility from a subset
 of the remaining hosts in each population at the end of the experiment.
 After 6 weeks of selective predation pressure, we found no differences in
 host abundance or infection prevalence across predation treatments.
 Counterintuitively, populations with selective predation on infected
 individuals had a higher abundance of infected individuals than
 populations where either uninfected or randomly selected individuals were
 removed. Additionally, populations with selective predation for uninfected
 individuals had a higher proportion of individuals infected after a
 standardized exposure to the parasite than individuals from the two other
 predation treatments. These results suggest that selective predation can
 alter the abundance of infected hosts and host evolution.
description: For the data files associated with the manuscript "Selective
 predation can impact infection prevalence and host susceptibility" by
 S.O. Gutierrez, X.E. Bernal, and C.L. Searle. Description of data files:
 Population_data_Gutierrez_etal Susceptibility_data_Gutierrez_etal
 Length_data_Gutierrez_etal For the file:
 "Population_data_Gutierrez_etal." These data are from the weekly
 sampling of the populations during the "population experiment"
 portion of the project. Beaker = replicate number Sample_num = the week
 each sample was taken Predation = the selective predation treatment where
 "Infected" = infected individuals were removed,
 "Uninfected" = uninfected individuals were removed, and
 "Random" = both infected and uninfected individuals were removed
 *Adult_F = uninfected adult female *Ephi_F = uninfected adult female
 carrying an ephippium (resting egg) *Juv_F = uninfected juvenile female
 *Ad_M = uninfected adult male *Juv_M = uninfected juvenile male *Inf_Ad_F
 = infected adult female *Inf_Ephi_F = infected adult female carrying an
 ephippium (resting egg) *Inf_Juv_F = infected juvenile female *Inf_Ad_M =
 infected adult male *Inf_Juv_M = infected juvenile male Total_num = total
 number of individuals counted in the 100mL sample Infected_num = number
 infected Prop_inf = proportion infected Prop_juv = proportion juveniles
 *Values in columns with an asterisk are the number of individuals in each
 category found in the 100mL subsample of the population on a given
 sampling day. For the file "Susceptibility_data_Gutierrez_etal."
 These data are the results of the infection trial in the "population
 susceptibility" portion of the project. Beaker = replicate number of
 the original population Predation = the selective predation treatment
 where "Infected" = infected individuals were removed,
 "Uninfected" = uninfected individuals were removed, and
 "Random" = both infected and uninfected individuals were removed
 Num_infected = the number of individuals identified as infected for each
 beaker at the end of the susceptibility trial Num_uninfected = the number
 of individuals identified as uninfected for each beaker at the end of the
 susceptibility trial For the file "Length_data_Gutierrez_etal."
 These data are the measurements of length from the extra animals in the
 maternal lines from the "population experiment" portion of the
 projection. Beaker = replicate number of the original population Mat_line
 = an indicator of the maternal line within each beaker (replicate). We
 started 20 maternal lines from each original beaker, but not all of them
 survived for us to measure. Indiv_num = an indicator of up to the three
 individuals measured for each maternal line within each beaker Length_mm =
 the length of each individual measured, in mm, from the middle of the eye
 to the base of the tail