Response of cladocerans to native and invasive invertebrate predators in Lake Simcoe, Canada
Loading...
Authors
Beckett, Anna
Date
Type
thesis
Language
eng
Keyword
zooplankton , invasive species
Alternative Title
Abstract
How populations respond to changing environmental conditions is critical to their
survival. Organisms can respond adaptively to new environmental conditions, for example an
invasive predator, by the expression of phenotypic plasticity, or evolution through selection for
certain phenotypes. Lake Simcoe, one of the largest inland lakes in Ontario, has been invaded by
several non-native species, including the zooplanktivore Bythotrephes cederstroemii, which is
native to north-central Europe and Asia. To investigate whether the arrival of Bythotrephes
and/or increase of Epischura abundance contributed to the zooplankton shifts observed in Lake
Simcoe in the mid-1990s, we conducted two laboratory experiments. Firstly i) a live predation
experiment to assess prey vulnerability and consumptive effects of each predator and ii) a
phototactic response experiment to assess differences in phototactic behaviour when prey
encounter the presence or absence of each predator cue. We found that bosminids were more
vulnerable than daphniids to Bythotrephes and Epischura predation and that all prey responded
to specific predator cue by altering their phototactic behaviour. Our predation results aligned
with the observed abundance changes in Lake Simcoe for some species, however they were
opposite to the abundance changes for others. Our phototactic results demonstrated that all
species are capable of changing their behaviour in response to predators, but in Lake Simcoe
other factors could be contributing to the observed changes. Although these results only explain
some of the observed changes in Lake Simcoe, they provide predictive insight into how future
invasion sites may respond to an invasive predator.
Description
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.