The Colonization of a Cold Spring Ecosystem by the Invasive Species Potamopyrgus Antipodarum (Gray, 1843) (Gastropoda: Tateidae) (Southern Poland)

Springs are unique aquatic environments that support specific biota, including endemic species and rare species listed in Red Lists. Due to their usually small size, springs are highly sensitive to disturbance. Many of them are threatened by aquifer depletion, contamination, surface-water diversion, livestock trampling, recreation, and invasive species. The aim of this study was to assess the colonization success of the invasive New Zealand mud snail (Potamopyrgus antipodarum) in a cold spring ecosystem in southern Poland. In Europe, this species has recently been added to the top “hundred worst” alien species due to its impact on invaded ecosystems. The study was carried out in two areas of the spring ecosystem—in the springhead and the springbrook—over a four-year period. Potamopyrus antipodarum dominated the benthic macroinvertebrate communities in both areas of the spring ecosystem. Nevertheless, its abundance in the springbrook was significantly greater, and increased noticeably during subsequent years compared to that in the springhead. The populations of P. antipodarum were exclusively composed of females. Smaller-sized New Zealand mudsnails were more abundant near the spring’s source than at the second site. The females at the springhead became fecund at sizes as small as 3.7 mm (the number of embryos was between 0 and 37), while at the springbrook, embryos were found in snails as small as 3.4 mm (the number of embryos was between 0 and 42). Our results suggest that the lower water temperature at the springhead may limit the population size of P. antipodarum, thus making its density too low to be able to affect the community structure of benthic macroinvertebrates, including the spring snail Bythinella cf. austriaca.

Assessment of the Effects of Environmental Concentrations of Microplastics on the Aquatic Snail Potamopyrgus antipodarum

Microplastics are ubiquitous in aquatic ecosystems. They can be found at the surface, in the water column, and in sediments. Multiple negative impacts of microplastics on aquatic organisms have been reported, with most studies focusing on marine ecosystems. However, the effects of microplastics on freshwater ecosystems have been less studied, with a few studies focusing on benthic invertebrates. In this study, we exposed the New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) to an environmental range of concentrations of polystyrene microparticles (size range from 0.01 to 514 µm at 100, 500, and 1000 mg microplastics/kg dry weight (dw) of sediment) and two supra-environmental concentrations (2000 and 4000 mg/kg dw sediment). The impacts of the exposure to microplastics on mortality, behavior, and reproduction were assessed at long-term exposure (31 days). Mortality and reproduction were not significantly affected by microplastics. On the contrary, most of the microplastic treatments altered the behavior, causing a significant increase in reaction time compared with controls (0 mg microplastics/kg dw sediment). The highest concentration (4000 mg/kg) did not have an impact on the reaction time over the experimental period compared with controls. To our knowledge, this study is the first to assess the effects of microplastics on the behavior of the aquatic snail P. antipodarum. Our results showed that at environmental concentrations, the behavior of P. antipodarum was the most sensitive variable to the adverse effects of polystyrene microplastics.

Using in-situ environmental DNA sampling to detect the invasive New Zealand Mud Snail (Potamopyrgus antipodarum) in freshwaters

Environmental DNA (eDNA) detection of aquatic invasive species is currently at the forefront of aquatic conservation efforts because the methodology provides a cost effective and sensitive means to detect animals at low densities. Developments in eDNA technologies have improved detection probabilities for rare, indicator, and invasive species over the past decade. However, standard lab analysis can take days or weeks before results are available and is prohibitive when rapid management decisions are required for mitigation. Here, we investigated the performance of a real-time quantitative PCR system for on-site eDNA detection of New Zealand mud snails (Potamopyrgus antipodarum). Six sites in western Washington, USA were sampled using the rapid eDNA technique and traditional methods, with five samples per site. On-site eDNA detection of mud snails resulted in a 10% increase in positive sites (16/30 = 53% positive) relative to visual surveys (13/30 = 43% positive). In addition, positive associations were observed between mud snail eDNA concentration (eDNA copies per reaction) and the number of mud snail individuals at each site (R2 = 0.78). We show that the rapid on-site eDNA technology can be effective for detection and quantification of New Zealand mud snails in freshwaters. This on-site eDNA detection approach could possibly be used to initiate management protocols that allow for more rapid responses during the onset of biological invasions.

Primera cita en África del caracol del cieno de Nueva Zelanda Potamopyrgus antipodarum (J.E. Gray, 1843) (Tateidae, Mollusca)

Incluido recientemente entre las “cien peores” especies invasoras y siendo el tercero de los “peores moluscos invasores” en Europa, el caracol del cieno de Nueva Zelanda ha llegado a ser cosmopolita. Se comunica el primer hallazgo en el continente africano, en Marruecos. Se encontraron poblaciones establecidas de Potamopyrgus antipodarum en el humedal Low Moulouya, un Sitio Ramsar y un Sitio de Interés Biológico y Ecológico (SIBE), donde ocupa hábitats naturales y antropogénicos (manantial, río y canal artificial). El proceso de invasión parece estar en sus primeras etapas, lo que exige medidas drásticas para poder controlar su progreso.

Can Potamopyrgus antipodarum (Gastropoda) affect the prevalence of Trichobilharzia szidati in Lymnaea stagnalis populations?

Swimmer's itch is an emerging disease caused by bird schistosomes affecting people all over the world. Lymnaeidae − main host snails in Europe − are the source of harmful cercariae of these zoonotic parasites. The aim of this work was to determine whether Polish lakes, inhabited by Potamopyrgus antipodarum (Gray, 1843), result in a lower potential risk of swimmer's itch compared to lakes uninhabited by this non-native snail species. As a result of the dilution effect created by increasing the diversity of co-occurring non-host targets for miracidia, the risk of this zoonosis may be reduced. We studied the prevalence of digenean trematodes in Lymnaea stagnalis (Linnaeus, 1758) populations from 30 water bodies partly inhabited by P. antipodarum. The bird schistosome infection in snail hosts was found in five lakes inhabited and 11 lakes uninhabited by the non-native snails. The prevalence of these parasitesin host snail populations in the lakes uninhabited was significantly higher than in lakes inhabited by P. antipodarum. We conclude that P. antipodarum seems to be a good potential target for reducing the risk of swimmer's itch via the dilution effect. We expect from our point of view to stimulate a discussion on the use of this species to protect bathing areas against the threat of swimmer's itch.