American Society of Ichthyologists and Herpetologists, Kansas City, Missouri, July 2002.

Predicting freshwater biogeographic patterns: development of a model based on Australia.

P.J. Unmack

Biogeographic patterns of obligate freshwater organisms are primarily constrained by four factors: drainage divides, sea level changes, climate change, and ecology. The latter two tend to have less discrete affects which are difficult to identify, and are more likely to differ in their influence among species. The former two are easily delineated and mapped, and should be more uniform in their affects on biota. Hence, biogeographic breaks relating to these barriers should be more pronounced in terms of the numbers of species affected. Here I outline a predictive model of biogeographic patterns across Australia based on drainage divides and sea level changes. This model will be tested by distributional data by examining three freshwater fish groups using genetic markers.