Clarifying an ambiguous evolutionary history: range-wide phylogeography of an Australian freshwater fish, golden perch (Macquaria ambigua).
Faulks LK, Gilligan DM and Beheregaray LB (2010) Clarifying an ambiguous evolutionary history: range-wide phylogeography of an Australian freshwater fish, golden perch (Macquaria ambigua). Journal of Biogeography, 37: 1329–1340.
Golden Perch (Macquaria ambigua) is one of the most widespread freshwater fishes in Australia, being distributed in both inland (Lake Eyre (LEB), Murray-Darling (MDB), and Bulloo (BULL)) and coastal basins (Fitzroy (FITZ)). Samples were collected from across the entire species distribution and the genetics of the species studied to investigate the relationship between environmental processes and evolutionary history, and contribute to fisheries management strategies. Three major genetic types corresponding to the major drainage basins were identified: FITZ, MDB, and LEB/BULL. Fish from the coastal basin (FITZ) were very different from those of the inland basins, and could be a separate species from which the inland forms evolved. From the coast, Golden Perch then crossed a major geographic barrier, the Great Dividing Range (GDR), to colonise the inland basins (MDB, LEB and BULL). The colonisation and expansion of populations occurred during much moister climate conditions of the Pleistocene, approximately 200 thousand years ago. However, as the climate became more arid, populations in the different basins became isolated from one another and the three major genetic types diverged. The populations from each drainage basin are now permanently isolated and may represent different species or subspecies. Therefore the management priorities for Golden Perch should include resolving the nature of the taxonomic differences among the genetic types from each basin. Also of importance is maintaining the genetic diversity of stocked populations, and protecting populations at risk due to increasingly arid conditions under climate change.