Dr Alejandro Trujillo-González1, Dr Rheyda Hinlo4, Sam Godwin, Dr Leon Barmuta2, Dr Anne Watson2,3, Dr Perpetua Turner2,3, Dr Amy Koch2,3, Professor Dianne Gleeson1
1University Of Canberra, Canberra, Australia, 2University of Tasmania, Hobert, Australia, 3Forest Practices Authority, Hobart, Australia, 4ACT Government Analytical Laboratory, Canberra, Australia
The giant freshwater crayfish, Astacopsis gouldi, is an endangered endemic freshwater species native to Northern Tasmania. Habitat loss, fishing pressure and climate change have been identified as threatening processes, and a current recovery plan requires routine population surveys to assess the impact of ongoing threats and recovery actions. We developed a novel species-specific probe-based assay targeting a 219 bp fragment in the Cytochrome Oxidase 1 gene region to detect traces of A. gouldi DNA in environmental samples as a cost effective, sensitive and non-invasive surveillance method to assess the presence of this endangered species. We tested assay specificity against ten crayfish species commonly found in Tasmania and determined assay sensitivity using tissue-derived genomic DNA and synthetic oligo standards designed for A. gouldi. We then tested water samples collected from aquaria and natural freshwater streams in Northern Tasmania with known occurrence of A. gouldi, as well as one site with no known A. gouldi occurrence. The probe-based assay designed in this study successfully detected A. gouldi DNA and eDNA with a 10 copies/µL limit of detection and showed no amplification of non-targeted co-existing crayfish species. We successfully detected the presence of A. gouldi eDNA in water samples from six sites with known occurrences of the species. There was no detection from the negative site. This study validates the use of eDNA-based detection of A. gouldi by real time PCR as a non-invasive monitoring tool to assist field monitoring, assessment and complement ongoing recovery actions to protect habitable ecosystems of A. gouldi.
Biography:
Alejandro is a Senior Research Fellow at the University of Canberra who specialises in environmental DNA-based applications in surveillance and biosecurity