Phenotypic Plasticity of the Introduced New Zealand Mud Snail, Potamopyrgus antipodarum, Compared to Sympatric Native Snails

Abstract

Phenotypic plasticity is likely to be important in determining the invasive potential of a species, especially if invasive species show greater plasticity or tolerance compared to sympatric native species. Here in two separate experiments we compare reaction norms in response to two environmental variables of two clones of the New Zealand mud snail, Potamopyrgus antipodarum, isolated from the United States, (one invasive and one not yet invasive) with those of two species of native snails that are sympatric with the invader, Fossaria bulimoides group and Physella gyrina group. We placed juvenile snails in environments with high and low conductivity (300 and 800 mS) in one experiment, and raised them at two different temperatures (16°C and 22°C) in a second experiment. Growth rate and mortality were measured over the course of 8 weeks. Mortality rates were higher in the native snails compared to P. antipodarum across all treatments, and variation in conductivity influenced mortality. In both experiments, reaction norms did not vary significantly between species. There was little evidence that the success of the introduced species is a result of greater phenotypic plasticity to these variables compared to the sympatric native species.

Sensitivity to dietary phosphorus limitation in native vs. invasive lineages of a New Zealand freshwater snail

“…Other studies of phenotypic plasticity in growth rate in US1, an invasive lineage of P. antipodarum from the western United States that we included in our experiment, demonstrate that US1 P. antipodarum exhibit phenotypic plasticity in response to temperature (Dybdahl and Kane , Levri et al. ), salinity (Drown et al. ), and conductivity (Levri et al.…”

“…While Dybdahl and Kane () did not compare the reaction norms between invasive and native snails in their invasive‐focused study, Levri et al. () found no difference in the reaction norms between native and invasive P. antipodarum under conditions that differed in conductivity. Although Drown et al.…”

“…), and conductivity (Levri et al. ). While Dybdahl and Kane () did not compare the reaction norms between invasive and native snails in their invasive‐focused study, Levri et al.…”

Adaptive phenotypic plasticity in a clonal invader

“…Latitude could perhaps better represent the annual mean temperature experienced by the snails than our point measurement at the time of collection. Numerous studies have shown that temperature and conductivity affect life history traits in P. antipodarum such as growth rate, fecundity, and survival (e.g., Bennett, Dudley, Cooper, & Sweet, 2014;Dybdahl & Kane, 2005;Gust et al, 2011;Herbst, Bogan, & Lusardi, 2008;Levri, Krist, Bilka, & Dybdahl, 2014;McKenzie et al, 2013). Conductivity can be linked to the presence of calcium, necessary for building the shell or producing embryos, but low ion concentrations may result in osmotic stress as well as increase the costs for calcium uptake (Herbst et al, 2008).…”

Genomic and phenotypic consequences of asexuality

“…The MTT assay and the JC-1 assay are commonly used in model system such as human , Okpalugo et al 2004, mouse (Fiorentino et al 1989, Wang et al 2016), and Drosophila (Terzhaz et al 2006, Xu et al 2015, but until now have not been adapted to suit measures of mitochondrial performance in mollusks. Of note, mollusks have several differences from other eukaryotes in their mitochondrial dynamics including the use of opines as alternate energy storage molecules (Harcet et al 2013), such that developing useful tools from other distantly related model organisms is not straightforward, despite a clear demand for mitochondrial assays in studying neurobiology (e.g., Vallejo et al 2014, Shomrat et al 2011, the biology of aging (Ungvari et al 2013), and understanding the energetic demands of invasive and/or problematic mollusk species (Baldwin et al 1996, Pigneur et al 2011, Levri et al 2014.…”