Mr Milad Khosravi1, Dr. Michelle T. Guzik1, Dr. Nicole E. White2, Prof. Steven J. B. Cooper1,3
1Department of Ecology and Evolutionary Biology, School of Biological Sciences, The University of Adelaide, Adelaide, Australia, 2Subterranean Research and Groundwater Ecology (SuRGE), Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Bentley, Australia, 3South Australian Museum, Adelaide, Australia
Biography:
Animals (freshwater fishes in particular), ecology and evolution are my main interests in life. I am currently a PhD researcher at The University of Adelaide focusing on developing eDNA methods to detect rare endangered species of blind Cave Gudgeons (Milyeringa spp.) and their populations within groundwater systems of Northwestern Australia.
Abstract:
The genus Milyeringa, comprises two endangered cave fish species endemics to the groundwater systems of the Cape Range Peninsula and Barrow Island in Western Australia. Given their restricted distribution and the logistical difficulty of accessing subterranean habitats, traditional biodiversity monitoring methods pose significant challenges. The development of effective and non-invasive bioassessment techniques are, therefore, critical for monitoring and conservation management of these rare species.
Here, we developed a genus-specific environmental DNA (eDNA) assay using the mitochondrial 16S rRNA gene to detect the presence/absence of Milyeringa species within their distribution range. Using a comprehensive approach to assay validation, a number of tests were undertaken. First, in silico analysis of inter-generic DNA sequences were used to ensure the assay’s specificity to the target genus, minimizing cross-amplification with non-target species. Second, in vitro tests were conducted to confirm the assay's sensitivity and efficiency in detecting Milyeringa DNA using genomic DNA and gBlock fragments and also to determine the assay’s limit of detection (LoD). Finally, in situ validation experiments were conducted using groundwater (eDNA) samples, demonstrating the assay's practicality and reliability in field conditions.
The results highlight the potential of eDNA analyses as a powerful and sensitive tool for the non-invasive monitoring of an endangered cave fish species. This eDNA-based method also provides a cost-effective and efficient alternative to traditional survey techniques for efficient investigation of these difficult-to-access habitats. We anticipate that our approach can facilitate regular and rigorous monitoring for future conservation studies and management efforts of these vulnerable species.