Evol Ecol Res 17: 225-242 (2016) Full PDF if your library subscribes.
Shifts in life-history traits of two introduced populations of threespine stickleback
Meredith L. Kurz1, David C. Heins1, Michael A. Bell2 and Frank A. von Hippel3
1Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, USA, 2Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, USA and 3Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
Correspondence: M.L. Kurz, School of Marine Science and Policy, University of Delaware, Newark, DE 19716, USA. email: email@example.com
Background: Anadromous threespine stickleback (Gasterosteus aculeatus) from Rabbit Slough were introduced into Cheney and Scout Lakes, Alaska in 2009 and 2011, respectively. The introductions were intended to model colonization of freshwater habitats by oceanic stickleback following the deglaciation of the Cook Inlet region, which resulted in a widely studied system of highly variable populations.
Hypothesis: Life-history traits of females in the colonizing lake populations will change from the ancestral phenotype within the first few generations after the experimental introductions, consistent with expectations for an opportunistic life-history strategy based on models for life-history change in invasive fishes. Females in the lakes are expected to reproduce at an earlier age and smaller size than anadromous females, and to exhibit greater reproductive effort (size-adjusted clutch mass) and clutch size (size-adjusted numbers of eggs). Changes in egg mass are difficult to predict because complex factors influence this life-history trait.
Methods: We quantified length, body mass, clutch mass, clutch size, and egg mass of wild-caught females from the anadromous source population and the two introduced lake populations during the first few years after introduction. In analyses of clutch mass, clutch size, and egg mass, we used body mass to correct for female size.
Results: As expected, age at reproduction and adult body size decreased while size-adjusted clutch size and reproductive effort increased. These changes occurred abruptly in the first year after introduction. Egg mass did not change in the first year post-introduction. Changes in life-history traits in subsequent years included larger mean egg mass and a greater proportion of females reproducing at age 2 instead of age 1.
Keywords: clutch mass, clutch size, egg mass, Gasterosteus aculeatus, reproduction, reproductive effort, threespine stickleback.
DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.
© 2016 Meredith L. Kurz. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.
Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.
All copies of abstracts and articles must preserve their copyright notice without modification.