30/05/2025
100 Years of Snails: Returning to the Field with New Eyes
This month, a dusty cupboard in the parasitology lab revealed an unexpected treasure — a meticulously preserved collection of freshwater snail specimens dating back nearly a century. Carefully labelled and stored in rows of specimen jars, the snails represent species from across the globe — from Southeast Asia to South Africa — but several were collected much closer to home: the NSW Southern Tablelands.
Remarkably, this is the same region where researchers from the Sydney School of Veterinary Science are currently conducting a Schnackenberg bequest-funded study on the intermediate hosts of Fasciola hepatica (liver fluke), a parasitic disease of livestock that continues to impose significant economic and welfare burdens across Australia.
“Finding specimens from the areas we’re now sampling was surreal,” says Dr Nichola Calvani, who leads the project in collaboration with researchers at the University of Melbourne Liver fluke in Australian livestock. “It’s like the past has handed us a benchmark.”
Among the specimens was a jar of tiny snails, carefully collected and labelled “Goulburn, Rapid Stream, 19.8.25” — almost exactly 100 years ago. This period marked a foundational era for parasitology in Australia. Researchers such as Ian Clunies Ross and Gordon Seddon were just beginning to map the complex life cycle of liver fluke in Australia, including its dependence on specific freshwater snail species as intermediate hosts. Field expeditions in the 1920s and 30s were instrumental in building the country’s first parasite and vector reference collections. This work was later continued in the McMaster Building of the then CSIR by Dr Joe Boray - the world's most well-recognised liver fluke scientist known for his foundatational work on F. hepatica epidemiology and control, including the development and commercialisation of Triclabendazole - the only drug still on the market with high efficacy against both adult and juvenile parasites.
While these trailblazing parasitologists relied on hand-drawn sketches and morphological identification, today’s team brings a different set of tools into the field. Drones are used to map wetland habitats and pinpoint likely snail microhabitats. Collected snails are then preserved in RNAlater and identified using molecular barcoding to resolve cryptic species and track shifts in host diversity and abundance across seasons.
Students are also playing a key role in the reinvigoration of liver fluke research in Australia. AVBS student Priscilla Huynh is leading an honours project mapping the current diversity, abundance and seasonality of liver fluke snails in the NSW Southern Tablelands, while AVBS placement student Adina Van Rysewyk is busy in the lab assisting in morphological identification, both of whom are helping to refine contemporary keys and reference data for native and invasive snails in the region with our collaborators at The University of Melbourne.
The rediscovered specimens are more than historical artefacts. They provide a rare opportunity to validate century-old species records and examine how key host populations may have shifted in response to climate change, land use, and the introduction of invasive species. “In many ways, this is a story about continuity,” says Calvani. “We’re returning to the same landscapes, asking some of the same questions — but with new technologies, and new urgency.”
As the project progresses, the team will share their findings with local farmers, industry groups, and veterinary students, helping to translate this research into improved strategies for parasite control. But for now, the century-old snails serve as a striking reminder: sometimes the best way forward is to look back.
