Oral Presentation Australian Society for Fish Biology Conference 2024

When traditional knowledge meets modern ecology - Range extension and insights into the life history of freshwater whiprays Urogymnus dalyensis (111623)

Barbara E Wueringer 1 2 , Amica Limosani 1 , Veronika N Biskis 1 3 , Christine Dudgeon 4 , Charmaine Bowen 5 , Anzac Frank 6 , Lawrence Jacko 5 , Fitzroy Lawrence 6 , Susan Marsh 7 , Lynley Wallis 8 , Christine Musgrave 7
  1. Sharks And Rays Australia, Bungalow, QLD, Australia
  2. School of Natural Sciences, Macquarie University, Wallumattagal Campus, NSW, Australia
  3. University of the Sunshine Coast, Hervey Bay, QLD, Australia
  4. School of Science, Technology and Engineering, University of the Sunshine Coast, Sunshine Coast, QLD, Australia
  5. Rinyirru Lakefield Aboriginal Corporation, Hopevale, QLD, Australia
  6. Kowanyama Land and Sea Rangers, Kowanyama, QLD, Australia
  7. Laura Aboriginal Land and Sea Rangers, Laura, QLD, Australia
  8. Griffith Centre for Social and Cultural Research, Griffith University, Nathan, QLD, Australia

The Australian freshwater whipray Urogymnus dalyensis was identified as a separate species from the Giant Freshwater whipray Urogymnus polylepis in 2008. For many years, this species was thought to be restricted to freshwater environments, but both morphological assessment of its sensory organs and acoustic telemetry data indicate that U. dalyensis is likely to tolerate higher salinity. Currently, this species is reported from select rivers in Northern Australia, extending from Western Australia to the Gulf of Carpentaria.

Citizen science reports to Sharks And Rays Australia (SARA) indicate that U. dalyensis also inhabits the east coast of Australia, from the tip of Cape York to the Cooktown region, with individuals documented in freshwater, coastal and reef environments. One juvenile ray, the smallest ever recorded, was captured and released in Rinyirru (Lakefield) National Park, with a disk width of 38cm. Large female rays up to 150 cm disk width have been documented through ecological surveys in the Mitchell River, also increasing the known size of the species. East coast rays were genetically sampled, and their species confirmed with genetic barcoding. Finally, archeological evidence also indicates that these locations are not new, as large rays are documented in rock art from the Laura Region.