Discerning the Ecological History of a Cyptogenic Marine Snail, Littorina Littorea

L.滨藜是新英格兰潮间带群落中的重要生态优势种，通过竞争和过度放牧影响着潮间带物种的分布和丰度。 尽管它的地位显赫，但它的地理历史仍然不清楚。 L. 1840年在北美新斯科舍省的皮克图首次记录到木桐。 在圣劳伦斯湾建立后的40年内，它向南传播了1500公里，到达纽约。 100多年来，科学家们一直在争论入侵美国东北部的种群是从欧洲引进的，还是原产于加拿大，并向南扩展了其范围。通常用来确定一个物种是否是非本地的一个特征是，与本地范围相比，引入种群的遗传多样性（创始人效应）减少。 通过对大西洋两岸的蜗牛种群进行基因测序，PI将辨别出L。美国东北部的一个小林地。 此外，L.在北美，littorea感染了至少五种营养传播的吸虫寄生虫。 因此，PI将采用一种新的第二种方法，通过检查引入区域内寄生虫物种本身遗传多样性的潜在减少。 由于寄生虫通常只感染一小部分宿主，PI预计创始人效应在与宿主一起引入的寄生虫中更为明显。 本研究采用多方面的方法来解决L。北美近岸群落的滨水区生态史。 这将为L.通过对山毛榉遗传多样性的分析，研究山毛榉的遗传多样性。石松及其吸虫寄生虫。智力优势。 该项目不仅将告知占主导地位的海洋物种的生态历史，而且还将开发一种强大的通用方法来告知许多隐源物种的起源。对寄生虫和宿主的遗传信号进行分析可能会被证明是揭示入侵物种生态历史的有力组合。 更广泛的影响。 该项目包括一名研究生和几名本科生的支持。该项目将为本科生创造指导研究的机会，特别是通过涉及在浅滩海洋实验室REU计划的学生。该项目的成果将在高影响力的期刊、科学会议上的演讲和一个公开网站上广泛传播。 如果这项工作的结果是有利的，他们将提供充足的数据，使一个强大的重新提交一个完整的建议，以支持在这个系统中的相关后续工作。

L. littorea is a conspicuous and ecologically dominant species in the intertidal community of New England, influencing the distribution and abundance of intertidal species through competition and heavy grazing. Despite its prominence, its biogeographic history remains unclear. L. littorea was first recorded in North America in 1840 in Pictou, Nova Scotia. Within 40 years of its establishment in the Gulf of Saint Lawrence, it had spread ~1500 km southwards to New York. For over 100 years scientists have debated whether the population that invaded the northeast United States was introduced from Europe or was native to Canada and expanded its range southwards. A characteristic often used to determine whether a species is nonindigenous is a reduction in its genetic diversity (founder effects) in the introduced population compared to the native range. By genetically sequencing snail populations on both sides of the Atlantic, the PIs will discern the ecological history of L. littorea in the northeastern United States. Additionally, L. littorea is infected with at least five trophically transmitted trematode parasites within North America. Thus, the PIs will employ a novel second approach by examining the potential reduction in the genetic diversity of the parasite species themselves in the introduced region. Since parasites typically infect only a fraction of hosts, the PIs expect founder effects to be more pronounced in parasites introduced with the hosts. This study uses a multifaceted approach to resolve L. littorea.s ecological history in the nearshore community of North America. New evidence will be generated on the biogeographic origin of L. littorea by assessing the genetic diversity of L. littorea and its trematode parasites. Intellectual Merit. Not only will this project inform the ecological history of a dominant marine species, but it will also develop a powerful general approach to inform the origin of many cryptogenic species. Analyses of genetic signals of both parasites and hosts may prove to be a powerful combination in unveiling the ecological history of invasive species. Broader Impacts. This project includes support of a graduate student and several undergraduates. This project will create mentored research opportunities for undergraduates in particular by involving a student at the Shoals Marine Laboratory REU program. Results of this project will be broadly disseminated in high impact journals, presentations at scientific meetings, and a publicly available website. If results of this work are favorable they will provide ample data to allow a strong resubmission of a full proposal to NSF to support related follow-up work in this system.