Adaptive responses and invasion: the role of plasticity and evolution in snail shell morphology

• Published in: Ecology and evolution 2013-02, Vol.3 (2), p.424-436
• Main Authors: Kistner, Erica J., Dybdahl, Mark F.
• Format: Article
• Language: English
• Subjects: Adaptation; Adaptive evolution; Biological evolution; Canonical variate analysis; Creeks & streams; Environmental conditions; Evolution; Evolution & development; Flow velocity; Gardens & gardening; Introduced species; Invasive species; Mollusks; Morphology; morphometric landmarks; Mud; Nonnative species; Original Research; Phenotypic plasticity; Plastic properties; Plasticity; Plastics; Population; Populations; Potamopyrgus antipodarum; Rivers; shell morphology
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.471

Invasive species often exhibit either evolved or plastic adaptations in response to spatially varying environmental conditions. We investigated whether evolved or plastic adaptation was driving variation in shell morphology among invasive populations of the New Zealand mud snail (Potamopyrgus antipodarum) in the western United States. We found that invasive populations exhibit considerable shell shape variation and inhabit a variety of flow velocity habitats. We investigated the importance of evolution and plasticity by examining variation in shell morphological traits 1) between the parental and F1 generations for each population and 2) among populations of the first lab generation (F1) in a common garden, full‐sib design using Canonical Variate Analyses (CVA). We compared the F1 generation to the parental lineages and found significant differences in overall shell shape indicating a plastic response. However, when examining differences among the F1 populations, we found that they maintained among‐population shell shape differences, indicating a genetic response. The F1 generation exhibited a smaller shell morph more suited to the low‐flow common garden environment within a single generation. Our results suggest that phenotypic plasticity in conjunction with evolution may be driving variation in shell morphology of this widespread invasive snail. Invasive species often exhibit either evolved or plastic adaptations in response to spatially varying environmental conditions. We tested for evolved and plastic responses in an introduced aquatic freshwater snail by examining variation in a key fitness component: shell morphology. Our results suggest that both plastic and genetic responses are driving shell shape variation in this widespread invasive snail.