Australian Society for Fish Biology, Hamilton, New Zealand, August 2013.

Murray-Darling Basin fishes: phylogenetic relationships and distributional patterns.

P.J. Unmack, C. Gonzalez-Orozco, M. Hammer, M. Adams, B. Gruber, A. Georges.

As the second largest river basin in Australia, Murray-Darling Basin has suffered major impacts from human development to the detriment of its fishes and other aquatic inhabitants. The combined effects of flow regulation, riparian vegetation removal, soil erosion and introduced species like redfin, trout and gambusia have decimated the fauna to where the majority of native fishes are now either extirpated, endangered or with significantly reduced ranges. Here we seek to improve our understanding of the evolutionary relationships of fishes, both in terms of their relationships to surrounding drainages and also the relationships within Murray-Darling Basin. Murray-Darling Basin is surrounded by more river basins than any other in Australia and thus has diverse relationships, primarily to the northeastern coastal drainages (primarily Burnett River), southern coastal drainages in western Victoria and northwest with the Lake Eyre Basin. Within the basin most species have low levels of genetic divergence and diversity which could be due to recent origins, bottlenecks and high dispersal abilities. We explore these patterns and highlight the need to understand biogeographic relationships in order to better manage and conserve remaining fish populations.