Metal accumulation in the shell and soft tissues of invasive mystery snails Management of Biological Invasions

Asian mystery snails (Cipangopaludina chinensis Gray, 1834 and Cipangopaludina japonica von Martens, 1861) were introduced to the United States in the 1890s and have since spread to waterbodies across the country. Besides the classic effects of invasive species, mystery snails may accumulate and distribute metals in invaded ecosystems. Few studies have evaluated this phenomenon in non-native mystery snail populations, specifically regarding partitioning of metals between different tissues and shells, and metal maternal transfer. Our goal was to compare metal concentrations (Cd, Cu, Ni, Pb, Zn) of shells, tissues, and environment of mystery snails, and the extent to which metals are maternally transferred. Mystery snails, water, and sediment were collected from several locations in northwestern Pennsylvania, USA, between 2021-2023. Metal concentrations in environmental matrices, tissues, and shells of mystery snails were evaluated via inductively coupled plasma mass spectrometry. Snail metal concentrations were compared to environmental concentrations to determine allocation between tissues and putative routes of accumulation. All five metals were detected in mystery snail tissues, with evidence of substantial accumulation of Cd, Pb, and Ni. Bioconcentration and biota sediment accumulation factors revealed that for most metals, accumulation may have occurred from water, likely reflecting snail feeding strategies and metal bioavailability. Significant correlations between maternal and offspring metal concentrations were found for all five metals, but Cu showed elevated concentrations in offspring compared to mothers. This suggests maternal transfer, increasing potential trophic transfer through predation on juvenile snails. Quantifying metal concentrations in mystery snails provides insight into potential exposure risks and trophic transfer, with implications for evaluating adverse effects in native species.