Quantifying reproductive state and predator effects on copepod motility in ephemeral ecosystems

Cuthbert, R. N., Dalu, T., Wasserman, R. J., Dick, J. T. A., Callaghan, A. ORCID: https://orcid.org/0000-0002-2731-3352, Froneman, P. W. and Weyl, O. L. F. (2019) Quantifying reproductive state and predator effects on copepod motility in ephemeral ecosystems. Journal of Arid Environments, 168. pp. 59-61. ISSN 0140-1963 doi: 10.1016/j.jaridenv.2019.05.010

Abstract/Summary

Ephemeral wetlands in arid environments are unique ecosystems with atypical trophic structuring, often dominated by invertebrate predation. Copepod behavioural traits and vulnerabilities to predation can vary substantially according to reproductive status. Gravid female copepods may be more vulnerable to predation due to reduced escape speeds or higher visibility to predators. Here, we quantify how reproductive status modulates horizontal motility rates of the predatory ephemeral pond specialist copepod Lovenula raynerae, and the responsiveness of the copepod to predator cues of the notonectid Anisops debilis. Males exhibited significantly higher motility rates than gravid female copepods, however chemical predator cues did not significantly influence activity rates in either sex. The lack of responsiveness to predator cues by specialist copepods in ephemeral wetlands may result from a lack of predation pressure in these systems, or due to time stress to reproduce during short hydroperiods. In turn, this could increase predation risk to copepods from externallyrecruited top predators in ephemeral wetlands, and potentially contribute to the development of skewed sex ratios in favour of females.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/85064
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Biological Sciences > Ecology and Evolutionary Biology
Publisher	Elsevier
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