Chinese Mystery Snail (Bellamya Chinensis) Ecology and Impacts

Chinese mystery snails (Bellamya chinensis) are an invasive aquatic species in North America, and populations have been found in southeast Nebraska reservoirs. Little is known about this species, but high densities suggest that there is the potential for considerable impacts on freshwater aquatic ecosystems. A group of researchers from the Nebraska Cooperative Fish and Wildlife Research Unit and the UNL School of Natural Resources are collaborating to expand the understanding of Chinese mystery snails. Research includes both field and lab components, with fieldwork focused on southeast Nebraska reservoirs.

Goals

To address research questions related to the invasive Chinese mystery snail. Aspects of the project include studies of life-history traits, habitat preferences, population size, movement capabilities, desiccation tolerance, feeding methods, possible predators, shell strength, mark retention, and distribution. Additionally, this project offers students an opportunity to conduct scientific investigation in a large team setting.

Current Status

Thus far, we have produced some interesting results. Following a mark-recapture study at Wild Plum Lake, Lancaster County, in September 2011, we estimated that there were approximately 664 adult snails within a 127 m2 transect (5.2 snails/m2), corresponding to an adult population size of approximately 250,000 snails in the littoral zone (<3 m in depth) and wet biomass of approximately 3,100 kg (643 kg/ha). A fecundity study assessment of 29 females yielded an average of 25 young per female with a maximum of 133 young in a given female. A mark retention study in the lab demonstrated that Chinese mystery snails marked with enamel paint did not completely lose a mark during the 181 day period. This result was further corroborated by finding marked snails 293 days after release at Wild Plum Lake. After the drought of 2012, a mortality event occurred at Wild Plum, and approximately 20% of the adult population died. Finally, temperature thresholds and limitations were identified, and adult snails survived acute freezing events (5 hours) and had upper survival limits around 45*C.