Life-history Trait Variation in Native vs. Invasive Asexual New Zealand Mud Snails

Life-history Trait Variation in Native vs. Invasive Asexual New Zealand Mud Snails | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Life-history Trait Variation in Native vs. Invasive Asexual New Zealand Mud Snails Carina Donne, Katelyn Larkin, Claire Adrian-Tucci, Abby Good, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-643210/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Potamopyrgus antipodarum is a New Zealand freshwater snail that is invasive worldwide. While native P. antipodarum populations are characterized by frequent coexistence between obligately sexual and obligately asexual individuals, only the asexual snails are known to invade other ecosystems. Despite low genetic diversity and the absence of sex, invasive asexual P. antipodarum are highly successful. Here, we quantified variation in three key life-history traits across invasive P. antipodarum lineages and compared this variation to already documented variation in these same traits in asexual native lineages to provide a deeper understanding of why some lineages become invasive. In particular, we evaluated 1) if invasive lineages of P. antipodarum could be successful because they represent life-history variation from native ancestors that could facilitate invasion, and 2) if invasive populations with higher genetic variation would display relatively high phenotypic variation. We found that invasive snails displayed a non-representative sample of native diversity, with invasive snails growing more slowly and maturing more rapidly than their native counterparts. These results are consistent with expectations of a scenario where invasive lineages represent a subset of native variation that is beneficial in the setting of invasion. Nevertheless, there was no evidence for a relationship between genetic and phenotypic variation, indicating that increased genetic variation does not necessarily translate into greater phenotypic variation, and consistent with earlier studies suggesting an important role for phenotypic plasticity in the P. antipodarum invasion. Together, these results help illuminate the mechanisms driving the worldwide expansion of invasive populations of these snails. Oceanography Biological invasions Potamopyrgus antipodarum Phenotypic variation Genetic variation freshwater snail Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Introduction Biological invasions have become a worldwide problem as a consequence of the increased spread of non-native species via anthropogenic activities (Mallez and McCartney 2018 ). Some non-native species will be able to establish in the novel environment, becoming invasive species that can pose serious problems such as decreasing native biodiversity and altering ecosystem function, and with the potential for severe economic impacts (Sakai et al. 2001 ). Species that are able to adapt more quickly to novel environments are more likely to become successful invaders (Colautti and Barrett 2013 ; Gozlan et al. 2020 ), with life-history trait (LHT) variation of particular potential relevance to invasion success (Dlugosch and Parker 2008a ; Dlugosch and Parker 2008b ; Li et al. 2015 ). In particular, high growth rate, rapid reproduction, and short life span - so-called R-selected traits (MacArthur and Wilson 1967 ; Bengtsson and Baur 1993 ) - tend to characterize invasive taxa (Sakai et al. 2001 ; Kimberling 2004 ), to the extent that Sakai et al. ( 2001 ) proposed that LHT variation across taxa could directly explain why some species become successful invaders while others do not. While it seems clear that taxa with R-selected LHT are often more likely to be invasive, we know comparatively little about why some lineages within species become invasive while others do not (Sakai et al. 2001 ; Neiman and Krist 2016 ). Under the logic that the same principle of characterizing LHT variation can be applied within taxa to understand invasiveness (Hierro et al. 2006 ; Eriksen et al. 2012 ), we evaluated intraspecific variation in LHT with respect to invasive status in a globally invasive New Zealand snail, Potamopyrgus antipodarum . These snails are destructive invaders, exemplified in the categorization of P. antipodarum as one of the “one-hundred worst” invasive species in Europe (Nentwig et al. 2018 ). Invasion success of P. antipodarum has been attributed to factors including high population growth rate and tolerance to a wide range of environmental conditions (Møller et al. 1994 ; Alonso and Castro-Diez 2008; Verhaegen et al. 2018a ) and adaptive phenotypic plasticity (Kistner and Dybdahl 2013 , 2014 ; Verhaegen et al. 2018a ; Verhaegen et al. 2018b ). Invasive P. antipodarum populations can achieve densities up to 800,000 individuals/m 2 (Dorgelo 1987 ; Møller et al. 1994 ; McKenzie et al. 2013 ), which might help explain why and how P. antipodarum can alter invaded ecosystems. This effect has been especially well documented in Polecat Creek, Wyoming, USA, where invasive P. antipodarum are found at densities as high as 500,000/m 2 (Hall et al. 2006), consume 75% of primary production, and alter nutrient cycles (Hall et al. 2003 ). Invasive P. antipodarum also have the potential to disrupt native food webs, with evidence from California and Utah that native fish – including the endangered tidewater goby ( Eucyclogobius newberryi) (Hellmair et al. 2011 ) and the rainbow trout ( Oncorhynchus mykiss) (Vinson and Baker 2008 ) – are losing weight as a consequence of consumption of consuming P. antipodarum , which have low nutritional value. Larkin et al. ( 2016 ) demonstrated substantial genetic variation for LHT phenotypes across native Potamopyrgus antipodarum asexual lineages (defined as all snails descended from a single asexual female), making this system a powerful candidate for assessing how intraspecific LHT variation might drive invasion success. These tiny New Zealand freshwater snails have invaded every continent except Antarctica and Africa in the last 200 years (Alonso and Castro-Diez 2012; Collado 2014 ). Although native-range P. antipodarum populations harbor sexual and asexual individuals, invasive P. antipodarum are exclusively asexual (Lively 1987 ; Alonso and Castro-Diez 2012). Similar to other invasive species, invasive P. antipodarum populations harbor low genetic diversity relative to the native range (Dybdahl and Drown 2011 ; Estoup et al. 2016 ; Verhaegen et al. 2018a ; Donne et al. 2020 ). High genetic diversity has been thought to be associated with successful invasion, but the likelihood that genetic variation will often be lost via founder effects during colonization leads to a potential “genetic paradox”: successful invasion despite low genetic variation (Dlugosch and Parker 2008; Dybdahl and Drown 2011 ; Estoup et al. 2016 ). While phenotypic plasticity likely plays some role in invasion success for P. antipodarum (Kistner and Dybdahl 2013 , 2014 ; Verhaegen et al. 2018a ; Verhaegen et al. 2018b ), the very low genetic diversity characterizing invasive populations of these snails makes P. antipodarum a powerful system to apply to the still-unresolved question of how species become successful invaders in the absence of genetic diversity (Dybdahl and Drown 2011 ; Estoup et al. 2016 ). Here, we used a common-garden approach to quantify variation in LHT of individual growth rate, age at maturity, and size at maturity across invasive lineages in P. antipodarum. We compared the means and variances of these LHT to the data from the same traits characterized by Larkin et al. ( 2016 ) in a large set of asexual P. antipodarum from the native range in New Zealand. These comparisons allow us to assess whether and to what extent the trait values and variation in the invasive lineages reflects that of the native snails. An outcome where the invasive snails consistently have LHT values that both reflect only a small fraction of the native range and are as expected under selection in a new habitat (e.g., for relatively rapid reproduction, early growth) is consistent with a scenario where selection favoring these phenotypes in the invaded range has played a major role. By contrast, if variation in invasive snails is similar to that of native snails and/or does not reflect expectations for selection in the invaded range, drift (including but not limited to founder effects) might be more likely than selection to be a primary evolutionary force in the invaded range (Keller and Taylor 2008 ). We also investigated whether genetic and phenotypic variation were associated across invasive P. antipodarum populations by using previously available SNP genotyping information for the invasive populations. A positive relationship between genetic and phenotypic variation would indicate that genetic variation could be relevant to invasive success. Regardless of particular outcomes, these comparisons between invasive and native ranges will provide insight into the mechanisms underlying invasion success of a destructive global invader. Methods We started by haphazardly selecting 40 asexual adult P. antipodarum females from each of seven laboratory cultures that were originally founded by single female P. antipodarum sampled from seven invasive populations in the United States and Belgium (Table 1 ). These “founding females” were isolated in individual one-liter cups filled with ~ 200 ml carbon-filtered tap water housed in a room held at 16℃. All snails were fed dried Spirulina ad libitum , which is standard for laboratory-cultured P. antipodarum (e.g., Zachar and Neiman, 2013 ). The three founding females from Lake Ontario (On) did not survive the initial experiment setup. We checked each of the remaining 37 founding female cups three times a week for newly born offspring (“G1”). Table 1 Characteristics of founding females. These eight 36-locus SNP genotypes represent results from the same collections reported in Donne et al. ( 2020 ), which are also used in the present study. Sampling Location Sample ID # Founding Females # Founders that Reproduced SNP Genotypes Geraardsbergen, Belgium Gb 8 2 328 Madison River, MO, USA Md 8 6 327 Gunpowder Falls, MD, USA Mr 5 5 327;333 Spring Creek, PA, USA PA 5 4 327 Polecat Creek, WY, USA Pc 6 4 327;332;338 Snake River, ID, USA Sn 5 4 327;332;333; 338;339;341 Lake Ontario, NY, USA On 3 0 328;336 For the first five G1s produced by each founding female, we recorded the date that each G1 was found and then isolated each G1 in an individual one-liter cup filled with ~ 200ml carbon-filtered water. We checked these G1 cups once a week until we observed calcification of the G1 shell, typically about a month after birth. We then measured the G1 to the nearest hundredth of a millimeter by placing the snail next to a ruler and taking a photo of the snail and ruler under a dissecting microscope. We then used ImageJ software to measure the length of each shell from the aperture to apex. We continued to check the G1 cups weekly, recording the date when a G1 reached 3 mm, which is considered the lower threshold of size for potential reproductive maturity for P. antipodarum females (McKenzie et al. 2013 ). We then continued to check G1 cups once a week for offspring (G2), and we recorded the date upon which the first G2 produced by each G1 was observed (“age at maturity”). On the day of first observation of G2 production, we again measured snail length as previously described (“final length”; P. antipodarum growth ends at or shortly prior to reproduction) (Winterbourn1970; McKenzie et al. 2013 ). Statistical analyses of life-history trait values We used these newly collected data as well as data collected in an identical manner from the same experimental setup in native asexual P. antipodarum (Larkin et al. 2016 ) to evaluate whether native vs. invasive status affected growth rate (growth per day of each G1 until 3 mm), age at maturity (age in number of days between G1 birth and G2 production), and final length (shell length at first reproduction for each G1). We started by using a Kolmogorov-Smirnov (K-S) test with the combined data from the invasive and native snails in order to evaluate whether the three dependent variables followed the normal distribution required for parametric analyses. While final length was normally distributed (K-S statistic = 0.030, df = 301, p = 0.200), age at maturity (K-S statistic = 0.111, df = 301, p < 0.001) and growth rate (K-S statistic = 0.080, df = 301, p < 0.001) were not. We then used an inverse square-root transformation to achieve normality for age at maturity (K-S statistic = 0.043, df = 301, p = 0.200), and we used an inverse log transformation to achieve normality for growth rate (K-S statistic = 0.045, df = 301, p = 0.200). Because Larkin et al. ( 2016 ) showed that growth rate is negatively correlated with age at maturity and positively correlated with final length in native-range asexual P. antipodarum , we used Kendall rank correlation to evaluate the relationship between growth rate and age at maturity and final length in the invasive snails. We used Kendall rank correlation because this analytical approach is not restricted to only linear relationships as are other correlation analyses. Similar to Larkin et al. ( 2016 ), age at maturity was negatively associated with growth rate and final length was positively associated with growth rate (age at maturity: tau = -0.516, p < 0.001; final length: tau = 0.163, p = 0.047). To analyze whether these LHT (growth rate, age at maturity and final length) differed between the native and invasive lineages, we used a three-level nested ANOVA model (α = 0.05) to analyze growth rate and a three-level nested ANCOVA model (α = 0.05), including growth rate as a covariate to analyze age at maturity and final length. Status (invasive vs. native) was a fixed main factor while population and family were random factors. Family (defined as all G1 produced by the same founding female) was nested within population (lake or stream of origin), allowing us to control for descent from the same founding female. Nesting population within status allowed us to account for variation contributed by the source of the population. Does genetic variation predict phenotypic variation? The invasive snails that we used for this experiment were sampled from populations that had been previously genotyped in Verhaegen et al. ( 2018a , b ) and Donne et al. ( 2020 ) (Table 1 ). We used these data to make an initial attempt to address whether genetic and phenotypic variation were associated across invasive populations. Under the presumption that phenotypic variation is at least partially linked to genetic variation, we expected that invasive populations with relatively low genetic variation should harbor less phenotypic variation than invasive populations with relatively high genetic variation. With specific respect to the populations that we used, we predicted that snails from populations Gb, Md and PA - each with only one genotype detected in Donne et al. ( 2020 ) - should exhibit low phenotypic variation relative to populations Sn and Pc, which harbored 6 and 5 SNP genotypes, respectively. We also predicted that populations Md and PA should display similar phenotypes because they share a SNP genotype. Finally, we evaluated whether there was a relationship between the extent to which there was significant among-family differences in LHT within invasive populations and population genetic variation, predicting a greater magnitude of among-family differentiation for populations with higher SNP genotype diversity. We addressed this possibility by using two-level nested ANOVA models (α = 0.05) for each of the eight invasive populations to determine whether the random factor of family differed in growth rate. We used the same approach but with a two-level nested ANCOVA model (α = 0.05), including growth rate as a covariate, to evaluate across-family variation in age at maturity and final length for each of the eight populations. We then used Kendall rank sum correlation analyses to determine whether the F statistic for the family factor for each invasive population from the one ANOVA and two ANCOVA analyses were associated with the number of SNP genotypes per population. We predicted that a situation where genotypic diversity reflected phenotypic diversity should manifest in a positive relationship between F statistics and population genotype number. Results Effect of status and population on life-history traits There was a significant effect of invasive status on growth rate, with invasive snails growing more slowly than native counterparts (Fig 1; p = 0.016). Invasive status also influenced age at maturity, with invasive snails maturing earlier than native snails (Fig 2; p < 0.001). The nested factor of population also affected growth rate (Fig. 4; p < 0.001) but did not influence age to maturity (Figure 5; p = 0.111). While invasive status did not affect final length (Fig. 3; p = 0.337), final length did differ across populations (Fig. 6; p < 0.001). We then used the R package ggplot2 v.3.2.1 to visually compare the distributions of the LHT between the native and invasive lineages, asking whether these distributions suggested that the invasive lineages reflected a non-representative sample of the variation found in the native lineages. These visual comparisons of the distribution of the growth rate and age and maturity data across native and invasive lineages were consistent with a situation where the invasive snails do not representatively feature native variation. In particular, the invasive snails exhibit the part of the native distribution associated with lower growth rate (Fig. 7) and earlier age of maturity (Fig. 8). By contrast, there was no evidence for non-representative sampling of final length between native and invasive lineages (Fig. 9). Genetic variation vs phenotypic variation Counter to predictions if genetic variation drives phenotypic variation, our comparisons of SNP genotype diversity against phenotypic variation or trait standard deviation (e.g., growth rate SD) did not reveal any obvious relationships (Figs. S1-3; Kendall’s rank sum correlations: growth rate: tau: -0.149, p = 0.687; age at maturity: tau = -0.149, p = 0.687; final length: tau = 0.00, p = 1.00). Our analysis of whether there existed relationships between the extent of within-population family-level variation for LHT in the invasive populations vs. population SNP genotypic diversity did not reveal evidence for such relationships (Figs. S4-6, Tables 2 and 3; Kendall’s rank sum correlations: growth rate: tau: -0.447, p = 0.227; age at maturity: tau = 0.00, p = 1.00; final length: tau = 0.00, p = 1.00). Table 2 Summary of outcomes of ANOVA/ANCOVA models evaluating the effect of family within invasive populations on life-history traits. Trait Population Effect F (df) p Growth rate Gb Md Mr PA Pc Sn Family(Population) 0.803(1,8) 8.184(2,5) 1.347(4,14) 2.712(3,12) 0.741(3,7) 0.963(3,10) 0.4 0.026 0.301 0.092 0.56 0.45 Age at maturity Gb Md Mr PA Pc Sn Family(Population) Growth rate 4.678(1,6) 0.166(1,6) 1.703(2,3) 28.501(1,3) 2.584(4,11) 2.202(1,11) 0.922(3,11) 5.486(1,11) 5.733(3,6) 19.446(1,6) 0.630(3,8) 10.487(1,8) 0.074 0.7 0.32 0.013 0.096 0.17 0.46 0.039 0.034 0.005 0.62 0.012 Final length Gb Md Mr PA Pc Sn Family(Population) Growth rate 0.951(1,6) 0.563(1,6) 67.452(2,3) 58.307(1,3) 7.125(4,11) 21.102(1,11) 0.419(3,11) 6.942(1,11) 0.780(3,5) 7.314(1,5) 1.922(2,6) 0.109(1,6) 0.37 0.48 0.003 0.005 0.004 0.001 0.74 0.023 0.55 0.043 0.23 0.75 Table 3 Summary of Kendall rank sum correlation analysis evaluating the relationship between F- statistics and number of SNP genotypes for invasive populations. Trait Kendall’s tau p Growth rate -0.447 0.23 Age at maturity 0.000 1 Final length 0.000 1 Discussion Our goal was to provide a deeper understanding of why some lineages within species become invasive, and in particular, if variation in life-history traits may help promote invasive success in P. antipodarum . This experiment revealed significant differences in growth rate and age at maturity between native and invasive snails, suggesting that invasive and native P. antipodarum differ with respect to important life-history traits. As expected, invasive lineages matured earlier than native lineages. This result is consistent with study outcomes in other invasive species (Chucholl 2012 ; Hôrková and Kováč 2014 ). By contrast, the lower growth rate in invasive vs native lineages departed both from our predictions and from studies in other invasive taxa (Chucholl 2012 ; Hôrková and Kováč 2014 ). Together, these data suggest that invasive P. antipodarum display some distinct life-history variation from native counterparts but do not wholly exhibit the suite of life-history trait variation commonly associated with invasion success. Invasive lineages almost exclusively reflect the relatively slow component of native variation in growth rate (Fig. 7 ). While this result also suggests that invasive lineages are capturing only a small fraction of the phenotypic distribution from native lineages, at face value, relatively low growth rate in invasive lineages differs from expectations for invasive populations. The lower growth rate that we observed in invasive P. antipodarum relative to native counterparts is particularly puzzling in light of the general expectation that early maturation is associated with rapid growth rate (Stearns and Koella 1986 ). One possible explanation for this result could lie in the distribution of phenotypic variation in native P. antipodarum . In particular, there is marked phylogeographic structure dividing North and South Island New Zealand P. antipodarum (Neiman and Lively 2004 ; Paczesniak et al. 2013 ). Because invasive P. antipodarum primarily originate directly or indirectly from the North Island (Städler et al. 2005 ; Donne et al. 2020 ), we considered whether the phenotype we observed - relatively low growth rate and early maturation - is a common feature of North Island P. antipodarum . We addressed this question by visually comparing life-history phenotypes across invasive P. antipodarum versus North Island and South Island-origin snails. This comparison revealed that while there do exist asexual lineages that harbor the combination of high growth rate and early maturation that we expected, these lineages are almost exclusively from South Island populations (Fig. 10 ). The implications are that the invasive P. antipodarum might tend to grow slowly because they did not sample genotypes associated with high growth rate. Because these invasive snails are asexual, there is no way - barring the generation of new phenotypes via mutation - for the rapid evolution of a combined high growth rate/early maturation phenotype. Because current sampling of North Island lineages is quite sparse (Fig. 10 ), additional wider characterization of phenotypic variation in North Island P. antipodarum will be needed to provide a more definitive test of this hypothesis. Relatively small size at maturity is commonly reported among invasive taxa (Sakai et al. 2001 ). Counter to this expectation, we did not observe a difference in final length between native and invasive P. antipodarum . It is important to note that these life-history generalizations may not apply to all invasive taxa. Indeed, Bengtsson and Baur ( 1993 ) found that size at maturity did not differ between invasive and native terrestrial gastropod species (primarily slugs and snails). Bengtsson and Baur ( 1993 ) went on to suggest that invasive species could exhibit a combination of r and k-selected traits rather than strictly r-selected traits. More recent studies do report that invasive species often differ in the traits associated with successful invasion (van Kleunen et al. 2015 ; Hodgins et al. 2018 ). Indeed, van Kluenen et al. (2015) suggests that invasive species do not have a “one size fits all” combination of traits that explains success. Population of origin affects life-history traits in P. antipodarum Growth rate and final length differed across invasive P. antipodarum populations (Figs. 4 and 6 ) . Evidence for population-level differences in growth rate in invasive P. antipodarum has also demonstrated by Dybdahl and Kane ( 2005 ), who showed that populations from Snake River, ID grew at higher rates at 24℃ than populations from Columbia River, OR and Madison River, MO. We found that snails from Snake River, ID grew more slowly than Madison River, MO in a common environment at 16℃. Because our experiment was conducted in a common-garden condition, it is tempting to conclude these differing responses are due to genetic adaptation to local habitat or nonadaptive population structure that translate into different responses to the laboratory conditions in which the experiment took place. A non-mutually exclusive explanation for these results is an adaptive plastic response to temperature. In particular, the Snake River population could fit a Master-of-some situation (Richards et al. 2006 ) where plasticity in LHT allows invasive snails to increase their fitness under favorable conditions. The across-population variation in final length is in agreement with previous studies in P. antipodarum , where shell height (similar measurement to present study: length of shell from the aperture to apex) in invasive European populations varied as a function of local habitat conditions. Thus, one possibility is that some of the across-population variation that we observed in final length could also be due to genetic adaptation to local habitat as well as nonadaptive heritable differences in size across invasive populations. Previous studies of P. antipodarum shell morphology have concluded that shell size is predominantly driven by phenotypic plasticity (Kistner and Dybdahl 2013 ; Verhaegen et al. 2018a ). In particular, Kistner and Dybdahl ( 2013 ) found significant differences in shell size between asexual founder females sampled from natural populations and their offspring produced in a lab setting. These phenotypic differences between mothers and their asexually produced offspring is expected if phenotypic plasticity plays an important role in determining shell size in invasive P. antipodarum . Determination of the extent to which these results regarding plasticity in shell size extend across P. antipodarum will require inclusion of a wide range of invasive populations and careful quantification of maternal vs. offspring shell size in controlled environmental conditions. Is there a relationship between genotypic and phenotypic variation? Invasive P. antipodarum populations may have non-representatively sampled native genetic variation that is beneficial for invasion. This possibility is consistent with the fact that invasive lineages of P. antipodarum display specific and narrow fractions of the life-history variation expressed in native P. antipodarum . In particular, the invasive lineages express primarily the early-maturation fraction of variation in this trait found in native P. antipodarum , suggesting that invasive lineages reflect a non-representative sample of native distribution (Fig. 8 ). Whether those observed phenotypic changes in invasive P. antipodarum are primarily due to natural selection versus genetic drift (e.g., founder effect) is a harder question to tackle. Keller and Taylor ( 2008 ) suggested that this question could be answered by using molecular markers to pair the invasive lineages (descendants) to the ancestral lineages found in the native range. With this information in hand, researchers can then use a common garden experiment to quantify and compare the phenotypic divergence between individuals sampled from the two ranges. Next, comparison of the genotypic diversity of the ancestor and descendants across neutral markers (e.g. microsatellites, SNPs) can allow the researchers to establish a neutral expectation of founder effect consequences for genetic diversity in the invasive population. If LHT are subject to selection, and if observed phenotypic change in these traits exceed the expectation of divergence at neutral loci between the native and invasive populations, it is reasonable to interpret this outcome as evidence for selection as a driver of the change in the invasive range. This conclusion is especially well supported if the direction of selection favors LHT that promote invasiveness (Keller and Taylor 2008 ). We do not have available the genetic data that we would need to differentiate between selection and genetic drift as the main mechanism for the different values and distributions of important LHT between native and invasive P. antipodarum populations. We did take initial steps towards this goal by using previously available SNP genotyping information for the invasive populations to evaluate whether genetic variation might be relevant to invasive success (Table 1 ). W predicted that populations with relatively high genotypic variation (e.g., Pc, Sn) would display more phenotypic variation than populations with lower genotypic variation (e.g., Gb, Md, PA). These comparisons of SNP genotype diversity against trait standard deviation (e.g., growth rate SD) did not reveal obvious relationships, counter to our prediction that greater genotypic variation would lead to greater phenotypic variation. It was especially striking that snails from Sn, which harbors six SNP genotypes, did not exhibit more phenotypic variation than any of the other invasive populations (Figs. S1-3). We similarly found no evidence for a relationship between the extent of across-family phenotypic variation and genotypic variation (Figs. S4-6). Although these results suggest that increased genetic variation does not necessarily translate into greater phenotypic variation in invasive P. antipodarum , a greater number of invasive populations sampled from a wider geographic range need to be genotyped and phenotyped to provide a rigorous test of this possibility. Summary & Conclusions We detected significant differences in growth rate and age at maturity between native and invasive P. antipodarum . These results - and especially the notably short time to maturity of invasive vs. native snails - suggest that these LHT could be important for invasion success. The invasive P. antipodarum exhibited lower growth rate than their native counterparts, counter to general assumptions that high growth rate is beneficial for invasive success. We did not detect a significant difference in final length between the native and invasive snails, which differs from predictions of life-history models that higher growth rate is associated with early maturation at a small body size (Stearns and Koella 1986 ). Our results also indicate that invasive P. antipodarum are non-representatively reflecting certain parts of the native-range variation, also consistent with the possibility that selection may favor those traits in the invasive range. Finally, we found no evidence for a strong relationship between genotypic diversity and phenotypic diversity in invasive populations, providing an indirect line of evidence in support of the idea that phenotypic plasticity is an important source of adaptive variation for these asexual snails. Altogether, our study helped illuminate connections between LHT variation and invasive success while also raising future questions about the invasive success of P. antipodarum. Future studies should aim to directly compare phenotypes and genotypes of ancestral lineages to descendent lineages to provide more insight into the role of genetic and phenotypic variation in invasion success. Declarations Acknowledgements We thank Josie Bliss, Mia Battani, Clara Lenger, Mikaela Johnson, Sydney Stork, Alex Kern, and Ben Ripperger for snail maintenance. We acknowledge Laura Bankers, Curt Bankers, Kyle McElroy, Bennett Brown, J.D. Woodell, and J. Moreno for help with collecting snails. We acknowledge Max Sampson and Tyler Dennis for help with statistical analyses. Steve Hendrix and Andrew Forbes provided helpful feedback on earlier versions of the manuscript. We are grateful to the Carver Trust, Rick and Linda Maxson, and the National Science Foundation Grant 1753851 for funding support. Funding: Carver Trust, Rick and Linda Maxson, National Science Foundation Grant 1753851 Conflicts of interest/Competing interests: None declared Ethics approval: Not applicable Consent to participate: Not applicable Consent for publication: Not applicable Availability of data and material: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Code availability: Not applicable References Alonso A, Castro-Díez P (2008) What explains the invading success of the aquatic mud snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)? Hydrobiologia 614:107–116 doi: 10.1007/s10750-008-9529-3 Alonso Á, Castro-Díez P (2012) The exotic aquatic mud snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca): State of the art of a worldwide invasion. Aquat Sci 74: 375–383 doi: 10.1007/s00027-012-0254-7 Bengtsson J, Baur B (1993) Do pioneers have r-selected traits ? Life-history patterns among colonizing terrestrial gastropods. Oecologia 94:17–22 Chucholl, C (2012) Understanding invasion success: Life-history traits and feeding habits of the alien crayfish Orconectes immunis (Decapoda, Astacida, Cambaridae). Knowl Manag Aquat Ecosyst 404 doi: 10.1051/kmae/2011082 Colautti RI, Barrett SCH (2013) Rapid adaptation to climate facilitates range expansion of an invasive plant. Science 342:364–366 doi: 10.1126/science.1242121 Collado GA (2014) Out of New Zealand: Molecular identification of the highly invasive freshwater mollusk Potamopyrgus antipodarum (Gray, 1843) in South America. Zool Stud 53 doi: 10.1186/s40555-014-0070-y Cox TJ, Rutherford JC (2000) Thermal tolerances of two stream invertebrates exposed to diurnally varying temperature. NZ J Mar Freshwater Res 34:203–208 doi: 10.1080/00288330.2000.9516926 Dlugosch KM, Parker IM (2008a) Founding events in species invasions: genetic variation, adaptive evolution, and the role of multiple introductions. Mol Ecol 17:431–449 doi: 10.1111/j.1365-294X.2007.03538.x Dlugosch KM, Parker IM (2008b) Invading populations of an ornamental shrub show rapid life history evolution despite genetic bottlenecks. Ecol Lett 11:701–709 doi:10.1111/j.1461-0248.2008.01181.x Donne C, Neiman M, Woodell JD, Haase M, Verhaegen G (2020) A layover in Europe: Reconstructing the invasion route of asexual lineages of a New Zealand snail to North America. Mol Ecol 29:3446–3465 doi: 10.1111/mec.15569 Dorgelo J (1987) Density fluctuations in populations (1982-1986) and biological observations of Potamopyrgus jenkinsi in two trophically differing lakes. Hydrobiol Bull 21:95–110 Dybdahl MF, Drown DM (2011) The absence of genotypic diversity in a successful parthenogenetic invader. Biol Invasions 13:1663–1672 doi: 10.1007/s10530-010-9923-4 Dybdahl MF, Kane SL (2005) Adaptation vs. phenotypic plasticity in the success of a clonal invader. Ecol 86:1592–1601 Eriksen RL, Desronvil T, Hierro JL, Kesseli R (2012) Morphological differentiation in a common garden experiment among native and non-native specimens of the invasive weed yellow starthistle ( Centaurea solstitialis ). Biol Invasions 14:1459–1467 doi: 10.1007/s10530-012-0172-6 Estoup A, Ravigné V, Hufbauer R, Vitalis R, Gautier M, Facon B (2016) Is there a genetic paradox of biological invasion? Annu Rev Ecol Evol Syst 47:51–72 doi: 10.1146/annurev-ecolsys-121415-032116 Gozlan RE, Záhorská E, Cherif E, Asaeda T, Britton JR, Chang CH, Hong T, Miranda R, Musil J, Povz M, Tarkan AS, Tricarico E, Trichkova T, Verreycken H, Weiperth A, Witkowski A, Zamora L, Zweimueller I, Zhao Y, Esmeili HR, Combe M (2020) Native drivers of fish life history traits are lost during the invasion process. Ecol Evol 10:8623–8633 doi: 10.1002/ece3.6521 Hall RO, Tank JL, Dybdahl MF (2003) Exotic snails dominate nitrogen and carbon cycling in a highly productive stream. Front Ecology Environ 1:407–411 doi: 10.1890/1540-9295(2003)001[0407:ESDNAC]2.0.CO;2 Hellmair M, Goldsmith G, Kinziger AP (2011) Preying on invasives: The exotic New Zealand mudsnail in the diet of the endangered tidewater goby. Biol Invasions 13:2197 doi: 10.1007/s10530-011-0054-3 Hierro JL, Villarreal D, Özkan Eren, Graham JM, Callaway RM (2006) Disturbance facilitates invasion: The effects are stronger abroad than at home. Am Nat 168:144–155 doi: https://doi.org/10.1086/505767 Hodgins KA, Bock DG, Rieseberg LH (2018) Trait evolution in invasive species. Annu Plant Rev 1 doi: 10.1002/9781119312994.apr0643 Hôrková K, Kováč V (2014) Different life-histories of native and invasive Neogobius melanostomus and the possible role of phenotypic plasticity in the species’ invasion success. Knowl Manag Aquat Ecosyst 412 doi: 10.1051/kmae/2013081 Jokela J, Lively CM, Dybdahl MF, Fox JA (1997) Evidence for a cost of sex in the freshwater snail Potamopyrgus antipodarum . Ecology 78:452–460 Keller SR, Taylor DR (2008) History, chance and adaptation during biological invasion: separating stochastic phenotypic evolution from response to selection. Ecol Lett 11:852–866 doi: 10.1111/j.1461-0248.2008.01188.x Kimberling DN (2004) Lessons from history: predicting successes and risks of intentional introductions for arthropod biological control. Biol Invasions 6:301–318 Kistner EJ, Dybdahl MF (2013) Adaptive responses and invasion: the role of plasticity and evolution in snail shell morphology. Ecol Evol 3:424–436 doi: 10.1002/ece3.471 Kistner EJ, Dybdahl MF (2014) Parallel variation among populations in the shell morphology between sympatric native and invasive aquatic snails. Biol Invasions 16:2615–2626 doi: 10.1007/s10530-014-0691-4 Larkin K, Tucci C, Neiman M (2016) Effects of polyploidy and reproductive mode on life history trait expression. Ecol Evol 6:765–778. doi: 10.1002/ece3.1934 Li XM, She DY, Zhang DY, Liao WJ (2015). Life history trait differentiation and local adaptation in invasive populations of Ambrosia artemisiifolia in China. Oecologia 177:669–677 doi: 10.1007/s00442-014-3127-z Lively CM (1987) Evidence from a New Zealand snail for the maintenance of sex by parasitism. Nature 328:519–521 Mallez S, McCartney M (2018) Dispersal mechanisms for zebra mussels : population genetics supports clustered invasions over spread from hub lakes in Minnesota. Biol Invasions 20:2461–2484 doi: 10.1007/s10530-018-1714-3 MacArthur RH, Wilson EO (1967) The theory of island biogeography . Princeton University Press, Princeton, NJ McKenzie VJ, Hall WE, Guralnick RP (2013) New Zealand mudsnails ( Potamopyrgus antipodarum) in Boulder Creek, Colorado: environmental factors associated with fecundity of a parthenogenic invader. Can J Zool 91:30–36 doi: 10.1139/cjz-2012-0183 Møller V, Forbes VE, Depledg MH (1994) Influence of acclimation and exposure temperature on the acute toxicity of cadmium to the freshwater snail Potamopyrgus antipodarum (Hydrobiidae). Environ Toxicol Chem 13:1519–1524 doi: 10.1002/etc.5620130914 Neiman M, Krist A (2016) Sensitivity to dietary phosphorus limitation in native vs. invasive lineages of New Zealand freshwater snail. Ecol Appl 26:2218–2224 doi: https://doi.org/10.1002/eap.1372 Neiman M, Lively CM (2004) Pleistocene glaciation is implicated in the phylogeographical structure of Potamopyrgus antipodarum , a New Zealand snail. Mol Ecol 13:3085–3098 doi: 10.1111/j.1365-294X.2004.02292.x Nentwig W, Bacher S, Kumschick S, Pyšek P, Vilà M (2018) More than “100 worst” alien species in Europe. Biol Invasions 20:1611–1621 doi: 10.1007/s10530-017-1651-6 Paczesniak D, Jokela J, Larkin K, Neiman M (2013) Discordance between nuclear and mitochondrial genomes in sexual and asexual lineages of the freshwater snail Potamopyrgus antipodarum. Mol Ecol 22:4695–4710 doi: 10.1111/mec.12422 Richards CL, Bossdorf O, Muth NZ, Gurevitch J, Pigliucci M (2006) Jack of all trades, master of some? On the role of phenotypic plasticity in plant invasions. Ecol Lett 9:981–993 doi: 10.1111/j.1461-0248.2006.00950.x Sakai AK, Allendorf, FW, Holt JS, Lodge DM, Molofsky J, With KA, Baughman S, Cabin RJ, Cohen JE, Ellstrand NC, McCauley DE, O’Neil P, Parker IM, Thompson JN, Weller SG (2001) The population biology of invasive species. Annu Rev Ecol Syst 32:305–332 doi: 10.1146/annurev.ecolsys.32.081501.114037 Städler T, Frye M, Neiman M, Lively CM (2005) Mitochondrial haplotypes and the New Zealand origin of clonal European Potamopyrgus , an invasive aquatic snail. Mol Ecol 14:2465–2473. doi: 10.1111/j.1365-294X.2005.02603.x Stearns SC, Koella JC (1986) The evolution of phenotypic plasticity in life-history traits: Predictions of reaction norms for age and size at maturity. Evolution 40:893–913 doi: 10.1111/j.1558-5646.1986.tb00560.x van Kleunen M, Dawson W, Maurel N (2015) Characteristics of successful alien plants. Mol Ecol 24:1954–1968. doi: 10.1111/mec.13013 Verhaegen G, Neiman M, McElroy KE, Bankers L, Haase M (2018a) Adaptive phenotypic plasticity in a clonal invader. Ecol Evol 8:4465–4483 doi: 10.1002/ece3.4009 Verhaegen G, Neiman M, Haase M (2018b) Ecomorphology of a generalist freshwater gastropod: Complex relations of shell morphology, habitat, and fecundity. Org Divers Evol 18:425–441 doi:10.1007/s13127-018-0377-3 Verhaegen G, Jungmeister KV, Haase M (2020) Life history variation in space and time: environmental and seasonal responses of a parthenogenetic invasive freshwater snail in northern Germany. Hydrobiologia 848:2153–2168 doi: 10.1007/s10750-020-04333-8 Vinson MR, Baker MA (2008) Poor growth of rainbow trout fed New Zealand mud snails. Potamopyrgus antipodarum N Am J Fish Manag 28:701–709. doi: 10.1577/m06-039.1 Winemiller KO, Rose KA (1992) Patterns of life-history diversification in North American fishes: implications for population regulation. Can J Fish Aquat Sci 49:2196–2218 doi: 10.1139/f92-242 Winemiller KO (2005) Life-history strategies, population regulation, and implications for fisheries management. Can J Fish Aquat Sci 62:872–885. doi: 10.1139/f05-040 Winterbourn M (1970) The New Zealand species of Potamopyrgus (Gastropoda:Hydrobiidae). Malacologia 10:283–321 Zachar N, Neiman M (2013) Profound effects of population density on fitness-related traits in an invasive freshwater snail. PLoS ONE 8:e80067 doi: 10.1371/journal.pone.0080067 Supplementary Files Donneetal.Supplemental.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 17 Sep, 2021 Reviewers invited by journal 03 Aug, 2021 Editor assigned by journal 21 Jun, 2021 First submitted to journal 20 Jun, 2021 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-643210","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":43661414,"identity":"cedccfdf-12b3-4463-bb44-8775e0d73813","order_by":0,"name":"Carina Donne","email":"","orcid":"","institution":"Colorado State University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Carina","middleName":"","lastName":"Donne","suffix":""},{"id":43661415,"identity":"5e106290-2249-4fc4-99e6-fd2dedb746cc","order_by":1,"name":"Katelyn Larkin","email":"","orcid":"","institution":"The University of Iowa","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Katelyn","middleName":"","lastName":"Larkin","suffix":""},{"id":43661416,"identity":"10ae36ec-43a5-4398-aa6b-9ee9a90d1c64","order_by":2,"name":"Claire Adrian-Tucci","email":"","orcid":"","institution":"The University of Iowa","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Claire","middleName":"","lastName":"Adrian-Tucci","suffix":""},{"id":43661417,"identity":"c52ad146-0dfb-4c0c-899f-543db6f02435","order_by":3,"name":"Abby Good","email":"","orcid":"","institution":"The University of Iowa","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Abby","middleName":"","lastName":"Good","suffix":""},{"id":43661418,"identity":"0a445af2-46c3-49b2-b9ab-348ddda391e7","order_by":4,"name":"Carson Kephart","email":"","orcid":"","institution":"The University of Iowa","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Carson","middleName":"","lastName":"Kephart","suffix":""},{"id":43661419,"identity":"58149d18-6ba3-4c86-a2fe-073b67a1190f","order_by":5,"name":"Maurine Neiman","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9ElEQVRIiWNgGAWjYLCCBDDJ2AAkbBjYIGLMRGtJI1ILEjgMY+DWott+xuzDwx02DObsza0bfu44n9jH3mP4gaHCOrEBhxazMznGMxLPpDFY9hxsu9l75nZiG88ZYwmGM+m4tRzIMWZIbDtcv+FGYtsN3jagFoncDRKMbYdxazn/BqTlP4PB/YdtN/+2nQNp2fyD8R8eLTfAthxgMLjB2Habt+0ASMs2CcYGfFqeFQO1JDMYnElsuy3blmzcxnP+m0XCsXRj3A5L3sz4s82OweD48Wc337bZyc5vb0u+8aHGWhaXFhwggTTlo2AUjIJRMArQAABAjGA0foPjPQAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-1543-8115","institution":"University of Iowa","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Maurine","middleName":"","lastName":"Neiman","suffix":""}],"badges":[],"createdAt":"2021-06-20 19:47:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-643210/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-643210/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":12158254,"identity":"0b899246-fbe0-4035-955f-4023d339b085","added_by":"auto","created_at":"2021-08-05 18:55:56","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":31747,"visible":true,"origin":"","legend":"There was a significant effect of invasive status on growth rate, with invasive snails growing more slowly than native counterparts (Fig 1; p = 0.016). ","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/a9732cbe27c2f7608da720d4.jpg"},{"id":12158252,"identity":"0efb765d-bc3c-4fe1-ba59-74692c84eb35","added_by":"auto","created_at":"2021-08-05 18:55:56","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":31251,"visible":true,"origin":"","legend":"Invasive status also influenced age at maturity, with invasive snails maturing earlier than native snails (Fig 2; p \u003c 0.001). ","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/28ee7781a06ef61e5124c451.jpg"},{"id":12158477,"identity":"3c981efb-3a49-4d7d-80d2-ad82caf0ec57","added_by":"auto","created_at":"2021-08-05 18:58:56","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":33347,"visible":true,"origin":"","legend":"While invasive status did not affect final length (Fig. 3; p = 0.337), final length did differ across populations (Fig. 6; p \u003c 0.001). ","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/578df3e59ca46f9b2f6d530c.jpg"},{"id":12158248,"identity":"ab041d4c-f823-440e-9238-80b88d50f81d","added_by":"auto","created_at":"2021-08-05 18:55:56","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":57361,"visible":true,"origin":"","legend":"Invasive status also influenced age at maturity, with invasive snails maturing earlier than native snails (Fig 2; p \u003c 0.001). The nested factor of population also affected growth rate (Fig. 4; p \u003c 0.001) ","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/1373f24b3abdc702f8f91ec3.jpg"},{"id":12158255,"identity":"41c64118-0410-4443-a137-e406e0ae3003","added_by":"auto","created_at":"2021-08-05 18:55:56","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":55029,"visible":true,"origin":"","legend":"Invasive status also influenced age at maturity, with invasive snails maturing earlier than native snails (Fig 2; p \u003c 0.001). The nested factor of population also affected growth rate (Fig. 4; p \u003c 0.001) but did not influence age to maturity (Figure 5; p = 0.111). While invasive status did not affect final length (Fig. 3; p = 0.337), final length did differ across populations (Fig. 6; p \u003c 0.001). ","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/718f84c145f0e97bb46d03b7.jpg"},{"id":12158253,"identity":"8a3b2d2d-a592-4263-b772-6abf4450a548","added_by":"auto","created_at":"2021-08-05 18:55:56","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":49533,"visible":true,"origin":"","legend":"Invasive status also influenced age at maturity, with invasive snails maturing earlier than native snails (Fig 2; p \u003c 0.001). The nested factor of population also affected growth rate (Fig. 4; p \u003c 0.001) but did not influence age to maturity (Figure 5; p = 0.111). While invasive status did not affect final length (Fig. 3; p = 0.337), final length did differ across populations (Fig. 6; p \u003c 0.001). ","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/3e316114eae2fe632dc4e958.jpg"},{"id":12158250,"identity":"9acd24df-aef2-40d5-b95a-63b5c87d9723","added_by":"auto","created_at":"2021-08-05 18:55:56","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":31772,"visible":true,"origin":"","legend":"In particular, the invasive snails exhibit the part of the native distribution associated with lower growth rate (Fig. 7) ","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/f7fdc1cadde78335c74472c2.jpg"},{"id":12158478,"identity":"e5049735-7bda-43b1-8a37-ab7ede23fb40","added_by":"auto","created_at":"2021-08-05 18:58:56","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":32964,"visible":true,"origin":"","legend":"In particular, the invasive snails exhibit the part of the native distribution associated with lower growth rate (Fig. 7) and earlier age of maturity (Fig. 8).","description":"","filename":"8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/48dffdb5b313abc88a39a425.jpg"},{"id":12158479,"identity":"deab219f-1ceb-4971-873d-c670196e987f","added_by":"auto","created_at":"2021-08-05 18:58:56","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":32140,"visible":true,"origin":"","legend":"By contrast, there was no evidence for non-representative sampling of final length between native and invasive lineages (Fig. 9). ","description":"","filename":"9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/c836397bdacfb6fc79adfc0a.jpg"},{"id":12158257,"identity":"a88b4f2b-af60-4ba5-a452-ace276f33cf5","added_by":"auto","created_at":"2021-08-05 18:55:56","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":42131,"visible":true,"origin":"","legend":"We addressed this question by visually comparing life-history phenotypes across invasive P. antipodarum versus North Island and South Island-origin snails. This comparison revealed that while there do exist asexual lineages that harbor the combination of high growth rate and early maturation that we expected, these lineages are almost exclusively from South Island populations (Fig. 10). ","description":"","filename":"10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/6e8a596e3679e63dc9fe3d4b.jpg"},{"id":13707565,"identity":"d5c6dd82-d43d-4bca-9369-64ac1d4a80a6","added_by":"auto","created_at":"2021-09-17 14:03:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":607430,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/5657722b-e783-4f29-9c54-a4cde6173389.pdf"},{"id":12158258,"identity":"d24e53e6-1b72-424d-ad4e-66f6cac74f97","added_by":"auto","created_at":"2021-08-05 18:55:57","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":26469899,"visible":true,"origin":"","legend":"","description":"","filename":"Donneetal.Supplemental.docx","url":"https://assets-eu.researchsquare.com/files/rs-643210/v1/f731f2a715d7b84993c14986.docx"}],"financialInterests":"","formattedTitle":"\u003cp\u003eLife-history Trait Variation in Native vs. Invasive Asexual New Zealand Mud Snails\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eBiological invasions have become a worldwide problem as a consequence of the increased spread of non-native species via anthropogenic activities (Mallez and McCartney \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Some non-native species will be able to establish in the novel environment, becoming invasive species that can pose serious problems such as decreasing native biodiversity and altering ecosystem function, and with the potential for severe economic impacts (Sakai et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2001\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSpecies that are able to adapt more quickly to novel environments are more likely to become successful invaders (Colautti and Barrett \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Gozlan et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), with life-history trait (LHT) variation of particular potential relevance to invasion success (Dlugosch and Parker \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2008a\u003c/span\u003e; Dlugosch and Parker \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2008b\u003c/span\u003e; Li et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). In particular, high growth rate, rapid reproduction, and short life span - so-called R-selected traits (MacArthur and Wilson \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e1967\u003c/span\u003e; Bengtsson and Baur \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e1993\u003c/span\u003e) - tend to characterize invasive taxa (Sakai et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Kimberling \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2004\u003c/span\u003e), to the extent that Sakai et al. (\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2001\u003c/span\u003e) proposed that LHT variation across taxa could directly explain why some species become successful invaders while others do not.\u003c/p\u003e \u003cp\u003eWhile it seems clear that taxa with R-selected LHT are often more likely to be invasive, we know comparatively little about why some lineages \u003cem\u003ewithin\u003c/em\u003e species become invasive while others do not (Sakai et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Neiman and Krist \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Under the logic that the same principle of characterizing LHT variation can be applied within taxa to understand invasiveness (Hierro et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Eriksen et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2012\u003c/span\u003e), we evaluated intraspecific variation in LHT with respect to invasive status in a globally invasive New Zealand snail, \u003cem\u003ePotamopyrgus antipodarum\u003c/em\u003e. These snails are destructive invaders, exemplified in the categorization of \u003cem\u003eP. antipodarum\u003c/em\u003e as one of the \u0026ldquo;one-hundred worst\u0026rdquo; invasive species in Europe (Nentwig et al. \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Invasion success of \u003cem\u003eP. antipodarum\u003c/em\u003e has been attributed to factors including high population growth rate and tolerance to a wide range of environmental conditions (M\u0026oslash;ller et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e1994\u003c/span\u003e; Alonso and Castro-Diez 2008; Verhaegen et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2018a\u003c/span\u003e) and adaptive phenotypic plasticity (Kistner and Dybdahl \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2013\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Verhaegen et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2018a\u003c/span\u003e; Verhaegen et al. \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2018b\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eInvasive \u003cem\u003eP. antipodarum\u003c/em\u003e populations can achieve densities up to 800,000 individuals/m\u003csup\u003e2\u003c/sup\u003e (Dorgelo \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e1987\u003c/span\u003e; M\u0026oslash;ller et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e1994\u003c/span\u003e; McKenzie et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2013\u003c/span\u003e), which might help explain why and how \u003cem\u003eP. antipodarum\u003c/em\u003e can alter invaded ecosystems. This effect has been especially well documented in Polecat Creek, Wyoming, USA, where invasive \u003cem\u003eP. antipodarum\u003c/em\u003e are found at densities as high as 500,000/m\u003csup\u003e2\u003c/sup\u003e (Hall et al. 2006), consume 75% of primary production, and alter nutrient cycles (Hall et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). Invasive \u003cem\u003eP. antipodarum\u003c/em\u003e also have the potential to disrupt native food webs, with evidence from California and Utah that native fish \u0026ndash; including the endangered tidewater goby (\u003cem\u003eEucyclogobius newberryi)\u003c/em\u003e (Hellmair et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2011\u003c/span\u003e) and the rainbow trout (\u003cem\u003eOncorhynchus mykiss)\u003c/em\u003e (Vinson and Baker \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2008\u003c/span\u003e) \u0026ndash; are losing weight as a consequence of consumption of consuming \u003cem\u003eP. antipodarum\u003c/em\u003e, which have low nutritional value.\u003c/p\u003e \u003cp\u003eLarkin et al. (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) demonstrated substantial genetic variation for LHT phenotypes across native \u003cem\u003ePotamopyrgus antipodarum\u003c/em\u003e asexual lineages (defined as all snails descended from a single asexual female), making this system a powerful candidate for assessing how intraspecific LHT variation might drive invasion success. These tiny New Zealand freshwater snails have invaded every continent except Antarctica and Africa in the last 200 years (Alonso and Castro-Diez 2012; Collado \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Although native-range \u003cem\u003eP. antipodarum\u003c/em\u003e populations harbor sexual and asexual individuals, invasive \u003cem\u003eP. antipodarum\u003c/em\u003e are exclusively asexual (Lively \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e1987\u003c/span\u003e; Alonso and Castro-Diez 2012). Similar to other invasive species, invasive \u003cem\u003eP. antipodarum\u003c/em\u003e populations harbor low genetic diversity relative to the native range (Dybdahl and Drown \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Estoup et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Verhaegen et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2018a\u003c/span\u003e; Donne et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). High genetic diversity has been thought to be associated with successful invasion, but the likelihood that genetic variation will often be lost via founder effects during colonization leads to a potential \u0026ldquo;genetic paradox\u0026rdquo;: successful invasion despite low genetic variation (Dlugosch and Parker 2008; Dybdahl and Drown \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Estoup et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). While phenotypic plasticity likely plays some role in invasion success for \u003cem\u003eP. antipodarum\u003c/em\u003e (Kistner and Dybdahl \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2013\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Verhaegen et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2018a\u003c/span\u003e; Verhaegen et al. \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2018b\u003c/span\u003e), the very low genetic diversity characterizing invasive populations of these snails makes \u003cem\u003eP. antipodarum\u003c/em\u003e a powerful system to apply to the still-unresolved question of how species become successful invaders in the absence of genetic diversity (Dybdahl and Drown \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Estoup et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2016\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHere, we used a common-garden approach to quantify variation in LHT of individual growth rate, age at maturity, and size at maturity across invasive lineages in \u003cem\u003eP. antipodarum.\u003c/em\u003e We compared the means and variances of these LHT to the data from the same traits characterized by Larkin et al. (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) in a large set of asexual \u003cem\u003eP. antipodarum\u003c/em\u003e from the native range in New Zealand. These comparisons allow us to assess whether and to what extent the trait values and variation in the invasive lineages reflects that of the native snails. An outcome where the invasive snails consistently have LHT values that both reflect only a small fraction of the native range and are as expected under selection in a new habitat (e.g., for relatively rapid reproduction, early growth) is consistent with a scenario where selection favoring these phenotypes in the invaded range has played a major role. By contrast, if variation in invasive snails is similar to that of native snails and/or does not reflect expectations for selection in the invaded range, drift (including but not limited to founder effects) might be more likely than selection to be a primary evolutionary force in the invaded range (Keller and Taylor \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). We also investigated whether genetic and phenotypic variation were associated across invasive \u003cem\u003eP. antipodarum\u003c/em\u003e populations by using previously available SNP genotyping information for the invasive populations. A positive relationship between genetic and phenotypic variation would indicate that genetic variation could be relevant to invasive success. Regardless of particular outcomes, these comparisons between invasive and native ranges will provide insight into the mechanisms underlying invasion success of a destructive global invader.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe started by haphazardly selecting 40 asexual adult \u003cem\u003eP. antipodarum\u003c/em\u003e females from each of seven laboratory cultures that were originally founded by single female \u003cem\u003eP. antipodarum\u003c/em\u003e sampled from seven invasive populations in the United States and Belgium (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). These \u0026ldquo;founding females\u0026rdquo; were isolated in individual one-liter cups filled with ~\u0026thinsp;200 ml carbon-filtered tap water housed in a room held at 16℃. All snails were fed dried \u003cem\u003eSpirulina ad libitum\u003c/em\u003e, which is standard for laboratory-cultured \u003cem\u003eP. antipodarum\u003c/em\u003e (e.g., Zachar and Neiman, \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). The three founding females from Lake Ontario (On) did not survive the initial experiment setup. We checked each of the remaining 37 founding female cups three times a week for newly born offspring (\u0026ldquo;G1\u0026rdquo;).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCharacteristics of founding females. These eight 36-locus SNP genotypes represent results from the same collections reported in Donne et al. (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), which are also used in the present study.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSampling Location\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSample ID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e# Founding Females\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e# Founders that Reproduced\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSNP Genotypes\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGeraardsbergen, Belgium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGb\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e328\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMadison River, MO, USA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMd\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e327\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGunpowder Falls, MD, USA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMr\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e327;333\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpring Creek, PA, USA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e327\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePolecat Creek, WY, USA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePc\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e327;332;338\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSnake River, ID, USA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSn\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e327;332;333;\u003c/p\u003e \u003cp\u003e338;339;341\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLake Ontario, NY, USA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOn\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e328;336\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFor the first five G1s produced by each founding female, we recorded the date that each G1 was found and then isolated each G1 in an individual one-liter cup filled with ~\u0026thinsp;200ml carbon-filtered water. We checked these G1 cups once a week until we observed calcification of the G1 shell, typically about a month after birth. We then measured the G1 to the nearest hundredth of a millimeter by placing the snail next to a ruler and taking a photo of the snail and ruler under a dissecting microscope. We then used ImageJ software to measure the length of each shell from the aperture to apex. We continued to check the G1 cups weekly, recording the date when a G1 reached 3 mm, which is considered the lower threshold of size for potential reproductive maturity for \u003cem\u003eP. antipodarum\u003c/em\u003e females (McKenzie et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). We then continued to check G1 cups once a week for offspring (G2), and we recorded the date upon which the first G2 produced by each G1 was observed (\u0026ldquo;age at maturity\u0026rdquo;). On the day of first observation of G2 production, we again measured snail length as previously described (\u0026ldquo;final length\u0026rdquo;; \u003cem\u003eP. antipodarum\u003c/em\u003e growth ends at or shortly prior to reproduction) (Winterbourn1970; McKenzie et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2013\u003c/span\u003e).\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analyses of life-history trait values\u003c/h2\u003e \u003cp\u003eWe used these newly collected data as well as data collected in an identical manner from the same experimental setup in native asexual \u003cem\u003eP. antipodarum\u003c/em\u003e (Larkin et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) to evaluate whether native vs. invasive status affected growth rate (growth per day of each G1 until 3 mm), age at maturity (age in number of days between G1 birth and G2 production), and final length (shell length at first reproduction for each G1). We started by using a Kolmogorov-Smirnov (K-S) test with the combined data from the invasive and native snails in order to evaluate whether the three dependent variables followed the normal distribution required for parametric analyses. While final length was normally distributed (K-S statistic\u0026thinsp;=\u0026thinsp;0.030, df\u0026thinsp;=\u0026thinsp;301, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.200), age at maturity (K-S statistic\u0026thinsp;=\u0026thinsp;0.111, df\u0026thinsp;=\u0026thinsp;301, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and growth rate (K-S statistic\u0026thinsp;=\u0026thinsp;0.080, df\u0026thinsp;=\u0026thinsp;301, \u003cem\u003ep\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001) were not. We then used an inverse square-root transformation to achieve normality for age at maturity (K-S statistic\u0026thinsp;=\u0026thinsp;0.043, df\u0026thinsp;=\u0026thinsp;301, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.200), and we used an inverse log transformation to achieve normality for growth rate (K-S statistic\u0026thinsp;=\u0026thinsp;0.045, df\u0026thinsp;=\u0026thinsp;301, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.200).\u003c/p\u003e \u003cp\u003eBecause Larkin et al. (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) showed that growth rate is negatively correlated with age at maturity and positively correlated with final length in native-range asexual \u003cem\u003eP. antipodarum\u003c/em\u003e, we used Kendall rank correlation to evaluate the relationship between growth rate and age at maturity and final length in the invasive snails. We used Kendall rank correlation because this analytical approach is not restricted to only linear relationships as are other correlation analyses. Similar to Larkin et al. (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), age at maturity was negatively associated with growth rate and final length was positively associated with growth rate (age at maturity: tau = -0.516, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001; final length: tau\u0026thinsp;=\u0026thinsp;0.163, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.047). To analyze whether these LHT (growth rate, age at maturity and final length) differed between the native and invasive lineages, we used a three-level nested ANOVA model (α\u0026thinsp;=\u0026thinsp;0.05) to analyze growth rate and a three-level nested ANCOVA model (α\u0026thinsp;=\u0026thinsp;0.05), including growth rate as a covariate to analyze age at maturity and final length. Status (invasive vs. native) was a fixed main factor while population and family were random factors. Family (defined as all G1 produced by the same founding female) was nested within population (lake or stream of origin), allowing us to control for descent from the same founding female. Nesting population within status allowed us to account for variation contributed by the source of the population.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eDoes genetic variation predict phenotypic variation?\u003c/h2\u003e \u003cp\u003eThe invasive snails that we used for this experiment were sampled from populations that had been previously genotyped in Verhaegen et al. (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2018a\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003eb\u003c/span\u003e) and Donne et al. (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). We used these data to make an initial attempt to address whether genetic and phenotypic variation were associated across invasive populations. Under the presumption that phenotypic variation is at least partially linked to genetic variation, we expected that invasive populations with relatively low genetic variation should harbor less phenotypic variation than invasive populations with relatively high genetic variation. With specific respect to the populations that we used, we predicted that snails from populations Gb, Md and PA - each with only one genotype detected in Donne et al. (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) - should exhibit low phenotypic variation relative to populations Sn and Pc, which harbored 6 and 5 SNP genotypes, respectively. We also predicted that populations Md and PA should display similar phenotypes because they share a SNP genotype. Finally, we evaluated whether there was a relationship between the extent to which there was significant among-family differences in LHT within invasive populations and population genetic variation, predicting a greater magnitude of among-family differentiation for populations with higher SNP genotype diversity. We addressed this possibility by using two-level nested ANOVA models (α\u0026thinsp;=\u0026thinsp;0.05) for each of the eight invasive populations to determine whether the random factor of family differed in growth rate. We used the same approach but with a two-level nested ANCOVA model (α\u0026thinsp;=\u0026thinsp;0.05), including growth rate as a covariate, to evaluate across-family variation in age at maturity and final length for each of the eight populations. We then used Kendall rank sum correlation analyses to determine whether the \u003cem\u003eF\u003c/em\u003e statistic for the family factor for each invasive population from the one ANOVA and two ANCOVA analyses were associated with the number of SNP genotypes per population. We predicted that a situation where genotypic diversity reflected phenotypic diversity should manifest in a positive relationship between \u003cem\u003eF\u003c/em\u003e statistics and population genotype number.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cu\u003eEffect of status and population on life-history traits\u0026nbsp;\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eThere was a significant effect of invasive status on growth rate, with invasive snails growing more slowly than native counterparts (Fig 1; \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.016). Invasive status also influenced age at maturity, with invasive snails maturing earlier than native snails (Fig 2; \u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001). The nested factor of population also affected growth rate (Fig. 4; \u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001) but did not influence age to maturity (Figure 5; \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.111). While invasive status did not affect final length (Fig. 3; \u003cem\u003ep =\u0026nbsp;\u003c/em\u003e0.337), final length did differ across populations (Fig. 6; \u003cem\u003ep \u0026lt;\u0026nbsp;\u003c/em\u003e0.001).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; We then used the R package \u003cem\u003eggplot2\u0026nbsp;\u003c/em\u003ev.3.2.1 to visually compare the distributions of the LHT between the native and invasive lineages, asking whether these distributions suggested that the invasive lineages reflected a non-representative sample of the variation found in the native lineages. \u0026nbsp;These visual comparisons of the distribution of the growth rate and age and maturity data across native and invasive lineages were consistent with a situation where the invasive snails do not representatively feature native variation. In particular, the invasive snails exhibit the part of the native distribution associated with lower growth rate (Fig. 7) and earlier age of maturity (Fig. 8). By contrast, there was no evidence for non-representative sampling of final length between native and invasive lineages (Fig. 9).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cu\u003eGenetic variation vs phenotypic variation\u0026nbsp;\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003eCounter to predictions if genetic variation drives phenotypic variation, our comparisons of SNP genotype diversity against phenotypic variation or trait standard deviation (e.g., growth rate SD) did not reveal any obvious relationships (Figs. S1-3; Kendall\u0026rsquo;s rank sum correlations: growth rate: tau: -0.149,\u003cem\u003e\u0026nbsp;p\u0026nbsp;\u003c/em\u003e= 0.687; age at maturity: tau = -0.149, \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.687; final length: tau = 0.00, \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 1.00). Our analysis of whether there existed relationships between the extent of within-population family-level variation for LHT in the invasive populations vs. population SNP genotypic diversity did not reveal evidence for such relationships (Figs. S4-6, Tables 2 and 3; Kendall\u0026rsquo;s rank sum correlations: growth rate: tau: -0.447, \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 0.227; age at maturity: tau = 0.00, \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 1.00; final length: tau = 0.00, \u003cem\u003ep\u0026nbsp;\u003c/em\u003e= 1.00).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u0026nbsp;\u003c/strong\u003eSummary of outcomes of ANOVA/ANCOVA models evaluating the effect of family within invasive populations on life-history traits.\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\" cellspacing=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"14.042553191489361%\"\u003e\n \u003cp\u003e\u003cstrong\u003eTrait\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.23404255319149%\"\u003e\n \u003cp\u003e\u003cstrong\u003ePopulation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"27.02127659574468%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEffect\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"19.148936170212767%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003eF\u003c/em\u003e(df)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"22.5531914893617%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"14.042553191489361%\"\u003e\n \u003cp\u003eGrowth rate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.23404255319149%\"\u003e\n \u003cp\u003eGb\u003c/p\u003e\n \u003cp\u003eMd\u003c/p\u003e\n \u003cp\u003eMr\u003c/p\u003e\n \u003cp\u003ePA\u003c/p\u003e\n \u003cp\u003ePc\u003c/p\u003e\n \u003cp\u003eSn\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"27.02127659574468%\"\u003e\n \u003cp\u003eFamily(Population)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"19.148936170212767%\"\u003e\n \u003cp\u003e0.803(1,8)\u003c/p\u003e\n \u003cp\u003e8.184(2,5)\u003c/p\u003e\n \u003cp\u003e1.347(4,14)\u003c/p\u003e\n \u003cp\u003e2.712(3,12)\u003c/p\u003e\n \u003cp\u003e0.741(3,7)\u003c/p\u003e\n \u003cp\u003e0.963(3,10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"22.5531914893617%\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003cp\u003e0.026\u003c/p\u003e\n \u003cp\u003e0.301\u003c/p\u003e\n \u003cp\u003e0.092\u003c/p\u003e\n \u003cp\u003e0.56\u003c/p\u003e\n \u003cp\u003e0.45\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"14.042553191489361%\"\u003e\n \u003cp\u003eAge at maturity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.23404255319149%\"\u003e\n \u003cp\u003eGb\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eMd\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eMr\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003ePA\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003ePc\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eSn\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"27.02127659574468%\"\u003e\n \u003cp\u003eFamily(Population)\u003c/p\u003e\n \u003cp\u003eGrowth rate\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"19.148936170212767%\"\u003e\n \u003cp\u003e4.678(1,6)\u003c/p\u003e\n \u003cp\u003e0.166(1,6)\u003c/p\u003e\n \u003cp\u003e1.703(2,3)\u003c/p\u003e\n \u003cp\u003e28.501(1,3)\u003c/p\u003e\n \u003cp\u003e2.584(4,11)\u003c/p\u003e\n \u003cp\u003e2.202(1,11)\u003c/p\u003e\n \u003cp\u003e0.922(3,11)\u003c/p\u003e\n \u003cp\u003e5.486(1,11)\u003c/p\u003e\n \u003cp\u003e5.733(3,6)\u003c/p\u003e\n \u003cp\u003e19.446(1,6)\u003c/p\u003e\n \u003cp\u003e0.630(3,8)\u003c/p\u003e\n \u003cp\u003e10.487(1,8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"22.5531914893617%\"\u003e\n \u003cp\u003e0.074\u003c/p\u003e\n \u003cp\u003e0.7\u003c/p\u003e\n \u003cp\u003e0.32\u003c/p\u003e\n \u003cp\u003e0.013\u003c/p\u003e\n \u003cp\u003e0.096\u003c/p\u003e\n \u003cp\u003e0.17\u003c/p\u003e\n \u003cp\u003e0.46\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.039\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.034\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.62\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e0.012\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"14.042553191489361%\"\u003e\n \u003cp\u003eFinal length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.23404255319149%\"\u003e\n \u003cp\u003eGb\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eMd\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eMr\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003ePA\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003ePc\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eSn\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"27.02127659574468%\"\u003e\n \u003cp\u003eFamily(Population)\u003c/p\u003e\n \u003cp\u003eGrowth rate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"19.148936170212767%\"\u003e\n \u003cp\u003e0.951(1,6)\u003c/p\u003e\n \u003cp\u003e0.563(1,6)\u003c/p\u003e\n \u003cp\u003e67.452(2,3)\u003c/p\u003e\n \u003cp\u003e58.307(1,3)\u003c/p\u003e\n \u003cp\u003e7.125(4,11)\u003c/p\u003e\n \u003cp\u003e21.102(1,11)\u003c/p\u003e\n \u003cp\u003e0.419(3,11)\u003c/p\u003e\n \u003cp\u003e6.942(1,11)\u003c/p\u003e\n \u003cp\u003e0.780(3,5)\u003c/p\u003e\n \u003cp\u003e7.314(1,5)\u003c/p\u003e\n \u003cp\u003e1.922(2,6)\u003c/p\u003e\n \u003cp\u003e0.109(1,6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"22.5531914893617%\"\u003e\n \u003cp\u003e0.37\u003c/p\u003e\n \u003cp\u003e0.48\u003c/p\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003cp\u003e0.004\u003c/p\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003cp\u003e0.74\u003c/p\u003e\n \u003cp\u003e0.023\u003c/p\u003e\n \u003cp\u003e0.55\u003c/p\u003e\n \u003cp\u003e0.043\u003c/p\u003e\n \u003cp\u003e0.23\u003c/p\u003e\n \u003cp\u003e0.75\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u0026nbsp;\u003c/strong\u003eSummary of Kendall rank sum correlation analysis evaluating the relationship between \u003cem\u003eF-\u003c/em\u003estatistics and number of SNP genotypes for invasive populations.\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\" cellspacing=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.92%\"\u003e\n \u003cp\u003e\u003cstrong\u003eTrait\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"34.56%\"\u003e\n \u003cp\u003e\u003cstrong\u003eKendall\u0026rsquo;s tau\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"31.52%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.92%\"\u003e\n \u003cp\u003eGrowth rate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"34.56%\"\u003e\n \u003cp\u003e-0.447\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"31.52%\"\u003e\n \u003cp\u003e0.23\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.92%\"\u003e\n \u003cp\u003eAge at maturity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"34.56%\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"31.52%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.92%\"\u003e\n \u003cp\u003eFinal length\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"34.56%\"\u003e\n \u003cp\u003e0.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"31.52%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur goal was to provide a deeper understanding of why some lineages within species become invasive, and in particular, if variation in life-history traits may help promote invasive success in \u003cem\u003eP. antipodarum\u003c/em\u003e. This experiment revealed significant differences in growth rate and age at maturity between native and invasive snails, suggesting that invasive and native \u003cem\u003eP. antipodarum\u003c/em\u003e differ with respect to important life-history traits. As expected, invasive lineages matured earlier than native lineages. This result is consistent with study outcomes in other invasive species (Chucholl \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; H\u0026ocirc;rkov\u0026aacute; and Kov\u0026aacute;č \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). By contrast, the lower growth rate in invasive vs native lineages departed both from our predictions and from studies in other invasive taxa (Chucholl \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; H\u0026ocirc;rkov\u0026aacute; and Kov\u0026aacute;č \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Together, these data suggest that invasive \u003cem\u003eP. antipodarum\u003c/em\u003e display some distinct life-history variation from native counterparts but do not wholly exhibit the suite of life-history trait variation commonly associated with invasion success.\u003c/p\u003e \u003cp\u003eInvasive lineages almost exclusively reflect the relatively slow component of native variation in growth rate (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e). While this result also suggests that invasive lineages are capturing only a small fraction of the phenotypic distribution from native lineages, at face value, relatively low growth rate in invasive lineages differs from expectations for invasive populations. The \u003cem\u003elower\u003c/em\u003e growth rate that we observed in invasive \u003cem\u003eP. antipodarum\u003c/em\u003e relative to native counterparts is particularly puzzling in light of the general expectation that early maturation is associated with rapid growth rate (Stearns and Koella \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e1986\u003c/span\u003e). One possible explanation for this result could lie in the distribution of phenotypic variation in native \u003cem\u003eP. antipodarum\u003c/em\u003e. In particular, there is marked phylogeographic structure dividing North and South Island New Zealand \u003cem\u003eP. antipodarum\u003c/em\u003e (Neiman and Lively \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Paczesniak et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Because invasive \u003cem\u003eP. antipodarum\u003c/em\u003e primarily originate directly or indirectly from the North Island (St\u0026auml;dler et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Donne et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), we considered whether the phenotype we observed - relatively low growth rate and early maturation - is a common feature of North Island \u003cem\u003eP. antipodarum\u003c/em\u003e.\u003c/p\u003e \u003cp\u003eWe addressed this question by visually comparing life-history phenotypes across invasive \u003cem\u003eP. antipodarum\u003c/em\u003e versus North Island and South Island-origin snails. This comparison revealed that while there do exist asexual lineages that harbor the combination of high growth rate and early maturation that we expected, these lineages are almost exclusively from South Island populations (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003e). The implications are that the invasive \u003cem\u003eP. antipodarum\u003c/em\u003e might tend to grow slowly because they did not sample genotypes associated with high growth rate. Because these invasive snails are asexual, there is no way - barring the generation of new phenotypes via mutation - for the rapid evolution of a combined high growth rate/early maturation phenotype. Because current sampling of North Island lineages is quite sparse (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003e), additional wider characterization of phenotypic variation in North Island \u003cem\u003eP. antipodarum\u003c/em\u003e will be needed to provide a more definitive test of this hypothesis.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eRelatively small size at maturity is commonly reported among invasive taxa (Sakai et al. \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). Counter to this expectation, we did not observe a difference in final length between native and invasive \u003cem\u003eP. antipodarum\u003c/em\u003e. It is important to note that these life-history generalizations may not apply to all invasive taxa. Indeed, Bengtsson and Baur (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e1993\u003c/span\u003e) found that size at maturity did not differ between invasive and native terrestrial gastropod species (primarily slugs and snails). Bengtsson and Baur (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e1993\u003c/span\u003e) went on to suggest that invasive species could exhibit a combination of r and k-selected traits rather than strictly r-selected traits. More recent studies do report that invasive species often differ in the traits associated with successful invasion (van Kleunen et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Hodgins et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Indeed, van Kluenen et al. (2015) suggests that invasive species do not have a \u0026ldquo;one size fits all\u0026rdquo; combination of traits that explains success.\u003c/p\u003e \u003cp\u003e \u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003ePopulation of origin affects life-history traits in\u003c/span\u003e \u003cspan type=\"ItalicUnderline\" class=\"ItalicUnderline\" name=\"Emphasis\"\u003eP. antipodarum\u003c/span\u003e\u003c/p\u003e \u003cp\u003eGrowth rate and final length differed across invasive \u003cem\u003eP. antipodarum\u003c/em\u003e populations (Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e and \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e. Evidence for population-level differences in growth rate in invasive \u003cem\u003eP. antipodarum\u003c/em\u003e has also demonstrated by Dybdahl and Kane (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2005\u003c/span\u003e), who showed that populations from Snake River, ID grew at higher rates at 24℃ than populations from Columbia River, OR and Madison River, MO. We found that snails from Snake River, ID grew more slowly than Madison River, MO in a common environment at 16℃. Because our experiment was conducted in a common-garden condition, it is tempting to conclude these differing responses are due to genetic adaptation to local habitat or nonadaptive population structure that translate into different responses to the laboratory conditions in which the experiment took place. A non-mutually exclusive explanation for these results is an adaptive plastic response to temperature. In particular, the Snake River population could fit a Master-of-some situation (Richards et al. \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) where plasticity in LHT allows invasive snails to increase their fitness under favorable conditions.\u003c/p\u003e \u003cp\u003eThe across-population variation in final length is in agreement with previous studies in \u003cem\u003eP. antipodarum\u003c/em\u003e, where shell height (similar measurement to present study: length of shell from the aperture to apex) in invasive European populations varied as a function of local habitat conditions. Thus, one possibility is that some of the across-population variation that we observed in final length could also be due to genetic adaptation to local habitat as well as nonadaptive heritable differences in size across invasive populations. Previous studies of \u003cem\u003eP. antipodarum\u003c/em\u003e shell morphology have concluded that shell size is predominantly driven by phenotypic plasticity (Kistner and Dybdahl \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Verhaegen et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2018a\u003c/span\u003e). In particular, Kistner and Dybdahl (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) found significant differences in shell size between asexual founder females sampled from natural populations and their offspring produced in a lab setting. These phenotypic differences between mothers and their asexually produced offspring is expected if phenotypic plasticity plays an important role in determining shell size in invasive \u003cem\u003eP. antipodarum\u003c/em\u003e. Determination of the extent to which these results regarding plasticity in shell size extend across \u003cem\u003eP. antipodarum\u003c/em\u003e will require inclusion of a wide range of invasive populations and careful quantification of maternal vs. offspring shell size in controlled environmental conditions.\u003c/p\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eIs there a relationship between genotypic and phenotypic variation?\u003c/h2\u003e \u003cp\u003eInvasive \u003cem\u003eP. antipodarum\u003c/em\u003e populations may have non-representatively sampled native genetic variation that is beneficial for invasion. This possibility is consistent with the fact that invasive lineages of \u003cem\u003eP. antipodarum\u003c/em\u003e display specific and narrow fractions of the life-history variation expressed in native \u003cem\u003eP. antipodarum\u003c/em\u003e. In particular, the invasive lineages express primarily the early-maturation fraction of variation in this trait found in native \u003cem\u003eP. antipodarum\u003c/em\u003e, suggesting that invasive lineages reflect a non-representative sample of native distribution (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWhether those observed phenotypic changes in invasive \u003cem\u003eP. antipodarum\u003c/em\u003e are primarily due to natural selection versus genetic drift (e.g., founder effect) is a harder question to tackle. Keller and Taylor (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2008\u003c/span\u003e) suggested that this question could be answered by using molecular markers to pair the invasive lineages (descendants) to the ancestral lineages found in the native range. With this information in hand, researchers can then use a common garden experiment to quantify and compare the phenotypic divergence between individuals sampled from the two ranges. Next, comparison of the genotypic diversity of the ancestor and descendants across neutral markers (e.g. microsatellites, SNPs) can allow the researchers to establish a neutral expectation of founder effect consequences for genetic diversity in the invasive population. If LHT are subject to selection, and if observed phenotypic change in these traits exceed the expectation of divergence at neutral loci between the native and invasive populations, it is reasonable to interpret this outcome as evidence for selection as a driver of the change in the invasive range. This conclusion is especially well supported if the direction of selection favors LHT that promote invasiveness (Keller and Taylor \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2008\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWe do not have available the genetic data that we would need to differentiate between selection and genetic drift as the main mechanism for the different values and distributions of important LHT between native and invasive \u003cem\u003eP. antipodarum\u003c/em\u003e populations. We did take initial steps towards this goal by using previously available SNP genotyping information for the invasive populations to evaluate whether genetic variation might be relevant to invasive success (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). W predicted that populations with relatively high genotypic variation (e.g., Pc, Sn) would display more phenotypic variation than populations with lower genotypic variation (e.g., Gb, Md, PA). These comparisons of SNP genotype diversity against trait standard deviation (e.g., growth rate SD) did not reveal obvious relationships, counter to our prediction that greater genotypic variation would lead to greater phenotypic variation. It was especially striking that snails from Sn, which harbors six SNP genotypes, did not exhibit more phenotypic variation than any of the other invasive populations (Figs. S1-3). We similarly found no evidence for a relationship between the extent of across-family phenotypic variation and genotypic variation (Figs. S4-6). Although these results suggest that increased genetic variation does not necessarily translate into greater phenotypic variation in invasive \u003cem\u003eP. antipodarum\u003c/em\u003e, a greater number of invasive populations sampled from a wider geographic range need to be genotyped and phenotyped to provide a rigorous test of this possibility.\u003c/p\u003e \u003c/div\u003e "},{"header":"Summary \u0026 Conclusions","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e\u003c/h2\u003e \u003cp\u003eWe detected significant differences in growth rate and age at maturity between native and invasive \u003cem\u003eP. antipodarum\u003c/em\u003e. These results - and especially the notably short time to maturity of invasive vs. native snails - suggest that these LHT could be important for invasion success. The invasive \u003cem\u003eP. antipodarum\u003c/em\u003e exhibited lower growth rate than their native counterparts, counter to general assumptions that high growth rate is beneficial for invasive success. We did not detect a significant difference in final length between the native and invasive snails, which differs from predictions of life-history models that higher growth rate is associated with early maturation at a small body size (Stearns and Koella \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e1986\u003c/span\u003e). Our results also indicate that invasive \u003cem\u003eP. antipodarum\u003c/em\u003e are non-representatively reflecting certain parts of the native-range variation, also consistent with the possibility that selection may favor those traits in the invasive range. Finally, we found no evidence for a strong relationship between genotypic diversity and phenotypic diversity in invasive populations, providing an indirect line of evidence in support of the idea that phenotypic plasticity is an important source of adaptive variation for these asexual snails.\u003c/p\u003e \u003cp\u003eAltogether, our study helped illuminate connections between LHT variation and invasive success while also raising future questions about the invasive success of \u003cem\u003eP. antipodarum.\u003c/em\u003e Future studies should aim to directly compare phenotypes and genotypes of ancestral lineages to descendent lineages to provide more insight into the role of genetic and phenotypic variation in invasion success.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003e\u003cu\u003eAcknowledgements\u0026nbsp;\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Josie Bliss, Mia Battani, Clara Lenger, Mikaela Johnson, Sydney Stork, Alex Kern, and Ben Ripperger for snail maintenance. We acknowledge Laura Bankers, Curt Bankers, Kyle McElroy, Bennett Brown, J.D. Woodell, and J. Moreno for help with collecting snails. We acknowledge Max Sampson and Tyler Dennis for help with statistical analyses. Steve Hendrix and Andrew Forbes provided helpful feedback on earlier versions of the manuscript. We are grateful to the Carver Trust, Rick and Linda Maxson, and the National Science Foundation Grant 1753851 for funding support.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFunding: Carver Trust, Rick and Linda Maxson, National Science Foundation Grant 1753851 Conflicts of interest/Competing interests: None declared\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEthics approval: Not applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConsent to participate: Not applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConsent for publication: Not applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAvailability of data and material: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003eCode availability: Not applicable\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAlonso A, Castro-D\u0026iacute;ez P (2008) What explains the invading success of the aquatic mud snail \u003cem\u003ePotamopyrgus antipodarum\u0026nbsp;\u003c/em\u003e(Hydrobiidae, Mollusca)? Hydrobiologia 614:107\u0026ndash;116 doi: 10.1007/s10750-008-9529-3\u003c/li\u003e\n \u003cli\u003eAlonso \u0026Aacute;, Castro-D\u0026iacute;ez P (2012) The exotic aquatic mud snail \u003cem\u003ePotamopyrgus antipodarum\u003c/em\u003e (Hydrobiidae, Mollusca): State of the art of a worldwide invasion. Aquat Sci 74: 375\u0026ndash;383 doi: 10.1007/s00027-012-0254-7\u003c/li\u003e\n \u003cli\u003eBengtsson J, Baur B (1993) Do pioneers have r-selected traits ? Life-history patterns among colonizing terrestrial gastropods. Oecologia 94:17\u0026ndash;22\u003c/li\u003e\n \u003cli\u003eChucholl, C (2012) Understanding invasion success: Life-history traits and feeding habits of the alien crayfish \u003cem\u003eOrconectes immunis\u003c/em\u003e (Decapoda, Astacida, Cambaridae). Knowl Manag Aquat Ecosyst 404 doi: 10.1051/kmae/2011082\u003c/li\u003e\n \u003cli\u003eColautti RI, Barrett SCH (2013) Rapid adaptation to climate facilitates range expansion of an invasive plant. Science 342:364\u0026ndash;366 doi: 10.1126/science.1242121\u003c/li\u003e\n \u003cli\u003eCollado GA (2014) Out of New Zealand: Molecular identification of the highly invasive freshwater mollusk \u003cem\u003ePotamopyrgus antipodarum\u003c/em\u003e (Gray, 1843) in South America. Zool Stud 53 doi: 10.1186/s40555-014-0070-y\u003c/li\u003e\n \u003cli\u003eCox TJ, Rutherford JC (2000) Thermal tolerances of two stream invertebrates exposed to diurnally varying temperature. NZ J Mar Freshwater Res 34:203\u0026ndash;208 doi: 10.1080/00288330.2000.9516926\u003c/li\u003e\n \u003cli\u003eDlugosch KM, Parker IM (2008a) Founding events in species invasions: genetic variation, adaptive evolution, and the role of multiple introductions. Mol Ecol 17:431\u0026ndash;449 doi: 10.1111/j.1365-294X.2007.03538.x\u003c/li\u003e\n \u003cli\u003eDlugosch KM, Parker IM (2008b) Invading populations of an ornamental shrub show rapid life history evolution despite genetic bottlenecks. Ecol Lett 11:701\u0026ndash;709 doi:10.1111/j.1461-0248.2008.01181.x\u003c/li\u003e\n \u003cli\u003eDonne C, Neiman M, Woodell JD, Haase M, Verhaegen G (2020) A layover in Europe: Reconstructing the invasion route of asexual lineages of a New Zealand snail to North America. Mol Ecol 29:3446\u0026ndash;3465 doi: 10.1111/mec.15569\u003c/li\u003e\n \u003cli\u003eDorgelo J (1987) Density fluctuations in populations (1982-1986) and biological observations of \u003cem\u003ePotamopyrgus jenkinsi\u0026nbsp;\u003c/em\u003ein two trophically differing lakes. Hydrobiol Bull 21:95\u0026ndash;110\u003c/li\u003e\n \u003cli\u003eDybdahl MF, Drown DM (2011) The absence of genotypic diversity in a successful parthenogenetic invader. Biol Invasions 13:1663\u0026ndash;1672 doi: 10.1007/s10530-010-9923-4\u003c/li\u003e\n \u003cli\u003eDybdahl MF, Kane SL (2005) Adaptation vs. phenotypic plasticity in the success of a clonal invader. Ecol 86:1592\u0026ndash;1601\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eEriksen RL, Desronvil T, Hierro JL, Kesseli R (2012) Morphological differentiation in a common garden experiment among native and non-native specimens of the invasive weed yellow starthistle (\u003cem\u003eCentaurea solstitialis\u003c/em\u003e). Biol Invasions 14:1459\u0026ndash;1467 doi: 10.1007/s10530-012-0172-6\u003c/li\u003e\n \u003cli\u003eEstoup A, Ravign\u0026eacute; V, Hufbauer R, Vitalis R, Gautier M, Facon B (2016) Is there a genetic paradox of biological invasion? Annu Rev Ecol Evol Syst 47:51\u0026ndash;72 doi: 10.1146/annurev-ecolsys-121415-032116\u003c/li\u003e\n \u003cli\u003eGozlan RE, Z\u0026aacute;horsk\u0026aacute; E, Cherif E, Asaeda T, Britton JR, Chang CH, Hong T, Miranda R, Musil J, Povz M, Tarkan AS, Tricarico E, Trichkova T, Verreycken H, Weiperth A, Witkowski A, Zamora L, Zweimueller I, Zhao Y, Esmeili HR, Combe M (2020) Native drivers of fish life history traits are lost during the invasion process. Ecol Evol 10:8623\u0026ndash;8633 doi: 10.1002/ece3.6521\u003c/li\u003e\n \u003cli\u003eHall RO, Tank JL, Dybdahl MF (2003) Exotic snails dominate nitrogen and carbon cycling in a highly productive stream. Front Ecology Environ 1:407\u0026ndash;411 doi: 10.1890/1540-9295(2003)001[0407:ESDNAC]2.0.CO;2\u003c/li\u003e\n \u003cli\u003eHellmair M, Goldsmith G, Kinziger AP (2011) Preying on invasives: The exotic New Zealand mudsnail in the diet of the endangered tidewater goby. Biol Invasions 13:2197 doi: 10.1007/s10530-011-0054-3\u003c/li\u003e\n \u003cli\u003eHierro JL, Villarreal D, \u0026Ouml;zkan Eren, Graham JM, Callaway RM (2006) Disturbance facilitates invasion: The effects are stronger abroad than at home. Am Nat 168:144\u0026ndash;155 doi:\u0026nbsp;\u003ca href=\"https://doi.org/10.1086/505767\"\u003ehttps://doi.org/10.1086/505767\u003c/a\u003e\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHodgins KA, Bock DG, \u0026nbsp;Rieseberg LH (2018) Trait evolution in invasive species. Annu Plant Rev 1 doi: 10.1002/9781119312994.apr0643\u003c/li\u003e\n \u003cli\u003eH\u0026ocirc;rkov\u0026aacute; K, Kov\u0026aacute;č V (2014) Different life-histories of native and invasive \u003cem\u003eNeogobius melanostomus\u003c/em\u003e and the possible role of phenotypic plasticity in the species\u0026rsquo; invasion success. Knowl Manag Aquat Ecosyst 412 doi: 10.1051/kmae/2013081\u003c/li\u003e\n \u003cli\u003eJokela J, Lively CM, Dybdahl MF, Fox JA (1997) Evidence for a cost of sex in the freshwater snail \u003cem\u003ePotamopyrgus antipodarum\u003c/em\u003e. Ecology 78:452\u0026ndash;460\u003c/li\u003e\n \u003cli\u003eKeller SR, Taylor DR (2008) History, chance and adaptation during biological invasion: separating stochastic phenotypic evolution from response to selection. Ecol Lett 11:852\u0026ndash;866 doi: 10.1111/j.1461-0248.2008.01188.x\u003c/li\u003e\n \u003cli\u003eKimberling DN (2004) Lessons from history: predicting successes and risks of intentional introductions for arthropod biological control. Biol Invasions 6:301\u0026ndash;318\u003c/li\u003e\n \u003cli\u003eKistner EJ, Dybdahl MF (2013) Adaptive responses and invasion: the role of plasticity and evolution in snail shell morphology. Ecol Evol 3:424\u0026ndash;436 doi: 10.1002/ece3.471\u003c/li\u003e\n \u003cli\u003eKistner EJ, Dybdahl MF (2014) Parallel variation among populations in the shell morphology between sympatric native and invasive aquatic snails. Biol Invasions 16:2615\u0026ndash;2626 doi: 10.1007/s10530-014-0691-4\u003c/li\u003e\n \u003cli\u003eLarkin K, Tucci C, Neiman M (2016) Effects of polyploidy and reproductive mode on life history trait expression. Ecol Evol 6:765\u0026ndash;778. doi: 10.1002/ece3.1934\u003c/li\u003e\n \u003cli\u003eLi XM, She DY, Zhang DY, Liao WJ (2015). Life history trait differentiation and local adaptation in invasive populations of \u003cem\u003eAmbrosia artemisiifolia\u003c/em\u003e in China. Oecologia 177:669\u0026ndash;677 doi: 10.1007/s00442-014-3127-z\u003c/li\u003e\n \u003cli\u003eLively CM (1987) Evidence from a New Zealand snail for the maintenance of sex by parasitism. Nature 328:519\u0026ndash;521\u003c/li\u003e\n \u003cli\u003eMallez S, McCartney M (2018) Dispersal mechanisms for zebra mussels : population genetics supports clustered invasions over spread from hub lakes in Minnesota. Biol Invasions 20:2461\u0026ndash;2484 \u0026nbsp;doi: 10.1007/s10530-018-1714-3\u003c/li\u003e\n \u003cli\u003eMacArthur RH, Wilson EO (1967) The theory of island biogeography\u003cem\u003e.\u003c/em\u003e Princeton University Press, Princeton, NJ\u003c/li\u003e\n \u003cli\u003eMcKenzie VJ, Hall WE, Guralnick RP (2013) New Zealand mudsnails (\u003cem\u003ePotamopyrgus antipodarum)\u0026nbsp;\u003c/em\u003ein Boulder Creek, Colorado: environmental factors associated with fecundity of a parthenogenic invader. Can J Zool 91:30\u0026ndash;36 doi: 10.1139/cjz-2012-0183\u003c/li\u003e\n \u003cli\u003eM\u0026oslash;ller V, Forbes VE, Depledg MH (1994) Influence of acclimation and exposure temperature on the acute toxicity of cadmium to the freshwater snail \u003cem\u003ePotamopyrgus antipodarum\u0026nbsp;\u003c/em\u003e(Hydrobiidae). Environ Toxicol Chem 13:1519\u0026ndash;1524 doi:\u0026nbsp;\u003ca href=\"https://doi.org/10.1002/etc.5620130914\"\u003e10.1002/etc.5620130914\u003c/a\u003e\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eNeiman M, Krist A (2016) Sensitivity to dietary phosphorus limitation in native vs. invasive lineages of New Zealand freshwater snail. Ecol Appl 26:2218\u0026ndash;2224 doi: https://doi.org/10.1002/eap.1372\u003c/li\u003e\n \u003cli\u003eNeiman M, Lively CM (2004) Pleistocene glaciation is implicated in the phylogeographical structure of \u003cem\u003ePotamopyrgus antipodarum\u003c/em\u003e, a New Zealand snail. Mol Ecol 13:3085\u0026ndash;3098 doi: 10.1111/j.1365-294X.2004.02292.x\u003c/li\u003e\n \u003cli\u003eNentwig W, Bacher S, Kumschick S, Py\u0026scaron;ek P, Vil\u0026agrave; M (2018) More than \u0026ldquo;100 worst\u0026rdquo; alien species in Europe. Biol Invasions 20:1611\u0026ndash;1621 doi: 10.1007/s10530-017-1651-6\u003c/li\u003e\n \u003cli\u003ePaczesniak D, Jokela J, Larkin K, Neiman M (2013) Discordance between nuclear and mitochondrial genomes in sexual and asexual lineages of the freshwater snail \u003cem\u003ePotamopyrgus antipodarum.\u003c/em\u003e Mol Ecol 22:4695\u0026ndash;4710 doi: 10.1111/mec.12422\u003c/li\u003e\n \u003cli\u003eRichards CL, Bossdorf O, Muth NZ, Gurevitch J, Pigliucci M (2006) Jack of all trades, master of some? On the role of phenotypic plasticity in plant invasions. Ecol Lett 9:981\u0026ndash;993 doi: 10.1111/j.1461-0248.2006.00950.x\u003c/li\u003e\n \u003cli\u003eSakai AK, Allendorf, FW, Holt JS, Lodge DM, Molofsky J, With KA, Baughman S, Cabin RJ, Cohen JE, Ellstrand NC, McCauley DE, O\u0026rsquo;Neil P, Parker IM, Thompson JN, Weller SG (2001) The population biology of invasive species. Annu Rev Ecol Syst 32:305\u0026ndash;332 doi: 10.1146/annurev.ecolsys.32.081501.114037\u003c/li\u003e\n \u003cli\u003eSt\u0026auml;dler T, Frye M, Neiman M, Lively CM (2005) Mitochondrial haplotypes and the New Zealand origin of clonal European \u003cem\u003ePotamopyrgus\u003c/em\u003e, an invasive aquatic snail. Mol Ecol 14:2465\u0026ndash;2473. doi: 10.1111/j.1365-294X.2005.02603.x\u003c/li\u003e\n \u003cli\u003eStearns SC, Koella JC (1986) The evolution of phenotypic plasticity in life-history traits: Predictions of reaction norms for age and size at maturity. Evolution 40:893\u0026ndash;913 doi: 10.1111/j.1558-5646.1986.tb00560.x\u003c/li\u003e\n \u003cli\u003evan Kleunen M, Dawson W, Maurel N (2015) Characteristics of successful alien plants. Mol Ecol 24:1954\u0026ndash;1968. doi: 10.1111/mec.13013\u003c/li\u003e\n \u003cli\u003eVerhaegen G, Neiman M, McElroy KE, Bankers L, Haase M (2018a) Adaptive phenotypic\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;plasticity in a clonal invader. Ecol Evol 8:4465\u0026ndash;4483 doi: 10.1002/ece3.4009\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eVerhaegen G, Neiman M, Haase M (2018b) Ecomorphology of a generalist freshwater gastropod: Complex relations of shell morphology, habitat, and fecundity. Org Divers Evol 18:425\u0026ndash;441 doi:10.1007/s13127-018-0377-3\u003c/li\u003e\n \u003cli\u003eVerhaegen G, Jungmeister KV, Haase M (2020) Life history variation in space and time: environmental and seasonal responses of a parthenogenetic invasive freshwater snail in northern Germany. Hydrobiologia 848:2153\u0026ndash;2168 doi: 10.1007/s10750-020-04333-8\u003c/li\u003e\n \u003cli\u003eVinson MR, Baker MA (2008) Poor growth of rainbow trout fed New Zealand mud snails. \u003cem\u003ePotamopyrgus antipodarum\u003c/em\u003e N Am J Fish Manag 28:701\u0026ndash;709. doi: 10.1577/m06-039.1\u003c/li\u003e\n \u003cli\u003eWinemiller KO, Rose KA (1992) Patterns of life-history diversification in North American fishes: implications for population regulation. Can J Fish Aquat Sci 49:2196\u0026ndash;2218 doi: 10.1139/f92-242\u003c/li\u003e\n \u003cli\u003eWinemiller KO (2005) Life-history strategies, population regulation, and implications for fisheries management. Can J Fish Aquat Sci 62:872\u0026ndash;885. doi: 10.1139/f05-040\u003c/li\u003e\n \u003cli\u003eWinterbourn M (1970) The New Zealand species of \u003cem\u003ePotamopyrgus\u0026nbsp;\u003c/em\u003e(Gastropoda:Hydrobiidae). Malacologia 10:283\u0026ndash;321\u003c/li\u003e\n \u003cli\u003eZachar N, Neiman M (2013) Profound effects of population density on fitness-related traits in an invasive freshwater snail. \u003cem\u003ePLoS ONE\u003c/em\u003e 8:e80067 doi: 10.1371/journal.pone.0080067\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"oecologia","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"oeco","sideBox":"Learn more about [Oecologia](https://www.springer.com/journal/442)","snPcode":"442","submissionUrl":"https://submission.nature.com/new-submission/442/3","title":"Oecologia","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Biological invasions, Potamopyrgus antipodarum, Phenotypic variation, Genetic variation, freshwater snail","lastPublishedDoi":"10.21203/rs.3.rs-643210/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-643210/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cem\u003ePotamopyrgus antipodarum \u003c/em\u003eis a New Zealand freshwater snail that is invasive worldwide. While native \u003cem\u003eP. antipodarum \u003c/em\u003epopulations are characterized by frequent coexistence between obligately sexual and obligately asexual individuals, only the asexual snails are known to invade other ecosystems. Despite\u0026nbsp;low genetic diversity and the absence of sex, invasive asexual \u003cem\u003eP. antipodarum \u003c/em\u003eare highly successful. Here, we quantified variation in three key life-history traits across invasive \u003cem\u003eP. antipodarum\u003c/em\u003e lineages and compared this variation to already documented variation in these same traits in asexual native lineages to provide a deeper understanding of why some lineages become invasive. In particular, we evaluated 1) if invasive lineages of \u003cem\u003eP. antipodarum \u003c/em\u003ecould be successful because they represent life-history variation from native ancestors that could facilitate invasion, and 2) if invasive populations with higher genetic variation would display relatively high phenotypic variation. We found that invasive snails displayed a non-representative sample of native diversity, with invasive snails growing more slowly and maturing more rapidly than their native counterparts. These results are consistent with expectations of a scenario where invasive lineages represent a subset of native variation that is beneficial in the setting of invasion. Nevertheless, there was no evidence for a relationship between genetic and phenotypic variation, indicating that increased genetic variation does not necessarily translate into greater phenotypic variation, and consistent with earlier studies suggesting an important role for phenotypic plasticity in the \u003cem\u003eP. antipodarum\u003c/em\u003e invasion. Together, these results help illuminate the mechanisms driving the worldwide expansion of invasive populations of these snails.\u003c/p\u003e","manuscriptTitle":"Life-history Trait Variation in Native vs. Invasive Asexual New Zealand Mud Snails","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-08-05 18:55:54","doi":"10.21203/rs.3.rs-643210/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2021-09-17T17:48:30+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2021-08-03T05:36:37+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2021-06-22T00:00:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"Oecologia","date":"2021-06-20T13:29:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"oecologia","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"oeco","sideBox":"Learn more about [Oecologia](https://www.springer.com/journal/442)","snPcode":"442","submissionUrl":"https://submission.nature.com/new-submission/442/3","title":"Oecologia","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"aad3080d-cb29-43d3-b5ea-fab50c6f0150","owner":[],"postedDate":"August 5th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":6253809,"name":"Oceanography"}],"tags":[],"updatedAt":"2022-06-20T00:06:41+00:00","versionOfRecord":[],"versionCreatedAt":"2021-08-05 18:55:54","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-643210","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-643210","identity":"rs-643210","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}