Sharks and Rays of Northern Australia’s Roper River, with a Range Extension for the Threatened Speartooth Shark Glyphis glyphis

Northern Australia represents an important region for the conservation of globally threatened sharks and rays; however, much of the region has been understudied. We aimed to survey the Roper River system of the Northern Territory of Australia for sharks and rays and compile records from other sources. Five shark and ray species were recorded, including four euryhaline species which can occur in any level of salinity, and one Critically Endangered marine species. This study found that the Roper River is a reproductive area for the observed euryhaline species and is used extensively, with some species extending almost 400 km upstream. Further research is required to understand the abundance and biology of sharks and rays in the Roper River, and how they may respond to human-driven threats.