Evolutionary history, landscape genetics and conservation of two Australian freshwater fishes, golden perch (Macquaria ambigua) and Macquarie perch (Macquaria australasica)
Faulks L (2010) Evolutionary history, landscape genetics and conservation of two Australian freshwater fishes, golden perch (Macquaria ambigua) and Macquarie perch (Macquaria australasica). PhD Thesis, Department of Biological Sciences, Macquarie University.
The biogeography of Australian freshwater fishes is a dynamic field of study, including the exploration of landscape evolution, fish ecology, climate, anthropogenic changes to ecosystems and population genetic diversity and structure. Two closely related Australian freshwater fishes with contrasting distributions, habitat preferences, life history strategies and conservation and management needs were investigated in this study: golden (Macquaria ambigua) and Macquarie (M. australasica) perch. Both species were found to have evolved on the east coast and crossed the Great Dividing Range during the Pleistocene (up to 2 million years ago) to colonise inland drainage basins such as the Murray-Darling and Lake Eyre. Strong population genetic structure is now evident in both species. Populations of golden perch from each basin are different from one another, whereas populations of Macquarie perch from different catchments can be different from one another. Levels of genetic diversity within each species are also different and these patterns are related to species specific biological characteristics. The habitat specialist, Macquarie perch, displays comparatively higher levels of genetic diversity and is related to the species preferred habitat. In contrast, genetic diversity among populations of golden perch is correlated to environmental conditions linked to the species ability to move and reproduce. There is a close association of historical and contemporary genetic characteristics with species biology and environmental conditions. Recognising these interactions is vital for conservation management strategies, e.g., understanding how past climate changes have impacted species can be valuable for predicting how they may respond under future climate change scenarios. In addition, this research has important implications for the management of these species by providing support for taxonomic revisions and the designation of population units for use in stocking programs.