Data from: Evaluating shell variation across different populations of a freshwater snail

The freshwater snail Potamopyrgus antipodarum has become a model system for studying invasion ecology, host–parasite coevolution, the maintenance of sexual reproduction and ecotoxicology. One understudied aspect of this snail is the variation in morphology within and among populations, which could provide insights into ecological differences across its native range. In this study of 17 New Zealand lake populations of P. antipodarum we used linear measurements and geometric morphometrics to compare several aspects of shell size and shape. We found that, except for those from Lake Te Anau, most lake populations of P. antipodarum differ slightly in shape, but differ significantly in size and in the presence of spines, where larger and spinier snails are found in deeper regions. These striking distinctions in size and shell armature, but not in shape, suggest that the various components of form are under different selective regimes. Snails from Lake Te Anau are different in both shape and size, implying that this population is diverging from the rest of the species in multiple ways, making it an interesting study population for further research.

新西兰异玻螺（Potamopyrgus antipodarum）已成为入侵生态学、宿主-寄生虫协同进化、有性繁殖维持以及生态毒理学研究的经典模式系统。目前该螺类尚有一个未被充分探索的研究维度：种群内部及种群间的形态变异，这类变异或可为揭示其原生分布区内的生态差异提供关键启示。本研究针对17个新西兰湖泊中的P. antipodarum种群，采用线性测量法与几何形态测量学（geometric morphometrics），对其壳体大小与形状的多方面特征开展对比分析。结果显示，除采自蒂阿瑙湖（Lake Te Anau）的种群外，多数P. antipodarum湖泊种群在壳体形状上仅存在细微差异，但在壳体大小以及棘突有无方面差异显著：个体更大、棘突更发达的螺类多栖息于较深水域。壳体大小与防护结构存在显著分化，而壳体形状并无此类特征差异，这表明形态的不同组分受到不同的选择压力调控。采自蒂阿瑙湖的螺类种群在壳体形状与大小上均表现出明显分化，意味着该种群正从该物种的其他种群中以多维度方式逐步分化，具备作为后续研究对象的重要研究价值。