Miss Liesel Morgan1, Dr Joel Huey1, Dr Nihara Gunawardene1

1Biologic Environmental Survey, East Perth, Australia

Biography:

Liesel has four years’ experience collecting, analysing and interpreting ecological and molecular data. This includes working in environmental consulting since 2021, as well as her honours research in taxonomy and systematics of Neuroptera. Her area of interest is in genetic taxonomic resolution, having predominantly worked with invertebrates but additionally with experience in flora and vertebrate samples. Liesel has extensive experience undertaking field work for short-range endemic and subterranean invertebrate fauna surveys in remote parts of Australia, especially in arid zones. She is consistently exploring improvements to sampling methodology to limit impact on potentially ecologically significant species, especially in the context of genetic techniques.

Abstract:

Land snails often exhibit high levels of endemism and are vulnerable to habitat degradation. As such, they are often targeted during short-range endemic (SRE) invertebrate fauna surveys for environmental impact assessments. Snail species identification can rely on multiple methods, including dissection, DNA barcoding from tissue and shell morphology. However, the former two methods necessitate euthanasia and studies on the latter show that shell morphology may vary within a species and cannot be relied upon for species identification (Hamilton, 2021). Having to euthanise an animal that is potentially ecologically significant raises ethical questions about removing them from the environment. The aim of this research was to investigate if it was possible to passively sample land snails without damage or euthanasia.

A trial was conducted on live Rhagada (Stylommatophora: Camaenidae) collected from Pilbara-based SRE surveys to determine if a mucus sample would be sufficient as a DNA sample. Individuals were encouraged out of their shells and onto sterile swabs to ‘walk’ around and leave a trail of mucus. These swabs were treated as a regular sub-sample of tissue and placed into buffer for DNA extraction, amplification and sequencing. From eleven individuals, nine sequences of Rhagada snails were successfully obtained, a rate comparable to current subsampling methods. This non-destructive method is planned to be tested under field conditions in future, where individuals can be released directly back into their habitat. The hope is that this method can be introduced to avoid euthanasia of potentially ecologically significant individuals.