Biodiversity of Australian freshwater planarians (Platyhelminthes: Tricladida: Paludicola): new species and localities, and a review of paludicolan distribution in Australia

On the basis of one extensive collection, the study provides new information on the diversity, taxonomy, anatomy and geographic distribution of 21 species of Australian freshwater planarians, including 7 species that are described as new. The material includes old type specimens of three species that have remained enigmatic since their collection and description almost 100 years ago, viz. Planaria rava Weiss, 1909, Romankenkius glandulosus (Kenk, 1930), and Planaria graffi Weiss, 1909. A biogeography of Australian freshwater planarians is documented by plotting all published distributional records for every known species. Thus, the present study forms a baseline for future studies on the diversity and biogeography of Australian freshwater planarians. Attention is drawn to the fact that the biotic relationships of several Australian taxa extend across the Pacific Ocean.