A New, Isolated Population of Carp Gudgeon ( <i>Hypseleotris</i> ) From Karijini National Park, Western Australia, With Phylogenetic Analyses

The Pilbara Freshwater Fish Biogeographic Province (Pilbara Province) of northern Western Australia is home to 15 described native freshwater fishes, with two representatives from Hypseleotris (carp gudgeons): the empire gudgeon H. compressa , and the golden carp gudgeon H. aurea . Hypseleotris compressa is widespread across northern and southeastern Australia also occurring in south-central Papua New Guinea and New Britain, whereas H. aurea is endemic to the Pilbara and mostly restricted to the Murchison and Gascoyne Rivers in the province’s south. Here, we present phylogenetic analyses of three specimens resembling Hypseleotris collected from Karijini National Park, outside of the typical range of H. compressa and H. aurea . A description of their collection location and habitat is also provided. The specimens formed a strongly supported monophyletic lineage within Hypseleotris , being at least 8.7% divergent from their closest relative H. aurea across 1,047 bp of the ND2 mitochondrial gene region. Their minimum divergence from H. aurea was greater than that recorded between several described Hypseleotris species from northwest Australia and the Indo-Pacific region, providing preliminary support for recognition as a distinct species. Our results add to the growing body of genetic evidence suggesting there are more native freshwater fish species in the Pilbara Province than the 15 currently described, highlighting the need for phylogenetic studies in conservation planning for the region’s ichthyofauna.