10.5061/DRYAD.FF94H
Wasserman, Ryan J.
Monash University Malaysia
Weston, Mark
Rhodes University
University of Cape Town
Weyl, Olaf L.F.
Department of Science and Technology
Froneman, P. William
Rhodes University
Welch, Rebecca J.
University of the Free State
Vink, Tim J.F.
South African Inst. for Aquatic Biodiversity (SAIAB); Grahamstown South Africa
Dalu, Tatenda
University of Venda
Vink, Tim J. F.
Nelson Mandela University
Data from: Sacrificial males: the potential role of copulation and
predation in contributing to copepod sex-skewed ratios
Dryad
dataset
2018
Mating Systems
predation pressure
Lovenula raynerae
prey vulnerability
Enithares sobria
2018-01-03T14:35:09Z
2018-01-03T14:35:09Z
en
https://doi.org/10.1111/oik.04832
17050 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Predation is thought to play a selective role in the emergence of
behavioural traits in prey. Differences in behaviour between prey
demographics may, therefore, be driven by predation with select components
of the population being less vulnerable to predators. While under
controlled conditions prey demography has been shown to have consequences
for predation success, investigations linking these implications to
natural prey population demographics are scarce. Here we assess
predator-prey dynamics between notonectid predators (backswimmers) and
Lovenula raynerae (Copepoda), key faunal groups in temperate ephemeral
pond ecosystems. Using a combination of field and experimental approaches
we test for the development and mechanism of predation-induced sex-skewed
ratios. A natural population of L. raynerae was tracked over time in
relation to their predator (notonectid) and prey (Cladocera) numbers. In
the laboratory, L. raynerae sex ratios were also assessed over time but in
the absence of predation pressure. Predation success and prey performance
experiments evaluating differences between L. raynerae male, female,
gravid female and copulating pairs exposed to notonectid predation were
then examined. Under natural conditions, a female dominated copepod
population developed over time and was correlated to predation pressure,
while under predator-free conditions non sex-skewed prey population
demographics persisted. Predator-prey laboratory trials showed no
difference in vulnerability and escape performance for male, female and
gravid female copepods, but pairs in copula were significantly more
vulnerable to predation. This vulnerability was not shared by both sexes,
with only female copepods ultimately escaping from successful predation on
a mating pair. These results suggest that contact periods during copula
may contribute to the development of sex-skewed copepod ratios over time
in ecosystems dominated by hexapod predators. This is discussed within the
context of vertebrate and invertebrate predation and how these dissimilar
types of predation are likely to have acted as selective pressures for
copepod mating systems.
Data_repository_fileThe study is comprised of a number of discrete
components, each addressing specific hypotheses, as outlined in Table 1 of
the associated Oikos manuscript. This data file is comprised of four data
sheets. Data sheet 1 (Sex ratio-Field) contains percentage data for male
and female Lovenula raynerae over the hydroperiod (Table 1- Field study).
Data sheet 2 (Sex ratio-Lab) contains raw count data for male and female
Lovenula raynerae, from a controlled laboratory experiment, over time
(Table 1- Experiment 1). Data sheet 3 (Predation success experiment)
contains raw count data from an experiment assessing predation success
between the predator (Enithares sobria) and prey (Lovenula raynerae)
(Table 1- Experiment 2). Data sheet 4 (Escape-Attack speed) contains
maximum swimming speed data (expressed in mm per second) for Lovenula
raynerae (prey) during escape events and for Enithares sobria (predator)
during attack events (Table 1- Experiment
3).Data_repository_3_read_only.xlsx