Standard Presentation (12 minutes) Australian Marine Sciences Association 2025 Conference

When traditional knowledge meets modern ecology - Range extension and insights into the life history of freshwater whiprays Urogymnus dalyensis (120787)

Barbara E Wueringer 1 2 , Amica Benoit-Limosani 1 , Veronika N Biskis 1 3 , Ross D Dwyer 4 , Christine Dudgeon 4 , Lynley Wallis 5 , Charmaine Bowen 6 , Anzac Frank 7 , Lawrence Jacko 6 , Fitzroy Lawrence 7 , Kelli Leatham 8 , Edwin Ling 8 , Susan Marsh 9 , Christine Musgrave 9
  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. Griffith Centre for Social and Cultural Research, Griffith University, Nathan, QLD, Australia
  6. Rinyirru Lakefield Aboriginal Corporation, Hopevale, QLD, Australia
  7. Kowanyama Land and Sea Rangers, Kowanyama, QLD, Australia
  8. Mapoon Land and Sea rangers, Mapoon Aboriginal Shire Council, Mapoon, Qld, Australia
  9. Laura Aboriginal Land and Sea Rangers, Laura, QLD, Australia

Urogymnus dalyensis was separated from Himantura polylepis in 2008, leaving many critical aspects of its biology, such as distribution, size, and salinity range, ambiguously documented. In 2016, both species were reassigned from Himantura to the Urogymnus genus. For a long time, U. dalyensis was considered to be restricted to freshwater environments, but recent assessment of its sensory organs and movement data indicate that it likely inhabits higher salinity habitats as well. The species is found in selected rivers in Northern Australia and PNG.

The combination of fieldwork, citizen science data, and Aboriginal rock art provides new insights into the biology of U. dalyensis. This species also inhabits the east coast of Australia, from the tip of Cape York to the Cooktown region, with specimens documented in upstream, coastal and reef environments. Large female rays up to 150 cm disk width have been documented through ecological surveys in the Mitchell River and Port Musgave, increasing the known size. East coast rays were confirmed to be U. dalyensis through genetic barcoding. Large rays are also present in the documented rock art from the Laura Region, indicating that the presence of this species on the east coast is not a recent range expansion.