Dissertation Research, Patterns of Diversity and Host Specificity in the Cestodes of Freshwater Stingrays

根据目前已知的情况，南美淡水黄貂鱼的绦虫似乎比它们的海洋同类物种多样性和宿主特异性要低得多。然而，新的数据表明，可能存在比以前认为的更多的物种，并且每种绦虫物种可能对其黄貂鱼宿主物种高度特异性。这个项目用分类学和系统的工具来研究这个问题。作为研究基础的绦虫标本包括存放在博物馆的标本和最近实地收集的标本。具体来说，将调查绦虫物种的两个属或组。从秘鲁新地点和黄貂鱼宿主收集的绦虫将采用以前未在该组中实施的方法进行研究，特别是组织学和扫描电子显微镜。新描述的物种的特征将与DNA序列数据增强。博物馆标本，包括许多位于巴西机构的标本，将与巴西圣保罗大学的费尔南多·马奎斯博士一起研究。对绦虫之间进化亲缘关系的测试将作为一个分析框架，用于探索广泛的进化问题，如宿主和寄生虫之间的共同进化、地理模式以及南美淡水黄貂鱼绦虫的起源。这项工作将阐明淡水系统和海洋系统中绦虫和黄貂鱼宿主之间是否存在根本差异。这项研究有可能为未来的进化生物学、系统学、生物地理学、生物多样性、生态学和保护等领域的研究提供有用的信息。对诸如秘鲁等南美国家的动物群进行基本的生物研究，既有助于记录生物多样性，又有助于在原产国更容易获得这种生物多样性的知识。标本被保存在收集它们的国家的博物馆里，供世界各地的科学家和初学者研究和分析。与马奎斯博士的合作具有互惠互利的潜力。这种跨国界分享鲜为人知的群体的专门知识的交流，将保存和扩大分类学专业知识，并导致结果在国际同行评议的期刊上联合发表，继续研究，以及彼此之间和未来学生之间的思想交流和合作努力。

Based on what is currently known, the tapeworms of South American freshwater stingrays appear to be much less diverse and host specific than their marine counterparts. However, new data indicate that there may be more species than previously thought, and that each tapeworm species may be highly specific to its stingray host species. This project investigates this problem with taxonomic and systematic tools. The tapeworm specimens that are the basis of the study include specimens deposited in museums, and specimens from recent field collections. Specifically two genera, or groups of tapeworm species, will be investigated. Tapeworms collected in Peru from new localities and stingray hosts will be studied with methods not previously implemented on the group, specifically histology and scanning electron microscopy. Characterization of newly described species will be augmented with DNA sequence data. Museum specimens, including many that are located at Brazilian institutions, will be studied in conjunction with Dr. Fernando Marques of the University of Sao Paulo, Brazil. Tests of evolutionary relatedness among the tapeworms will serve as an analytical framework to explore broad evolutionary questions such as coevolution between host and parasite, geographic patterns, and the origin of the tapeworms of South American freshwater stingrays. This work will shed light on whether there are fundamental differences between the freshwater and marine systems of tapeworms and stingray hosts. This study has the potential to generate information useful and applicable to future studies focusing on evolutionary biology, systematics, biogeography, biodiversity, ecology, and conservation. Basic organismal research on the fauna of South American countries such as Peru serves to both document biological diversity and make knowledge of that biodiversity more available within the country of origin. Specimens are deposited in museums in the country from which they were collected, and these become available for study and analysis by scientists throughout the world, as well as beginning students. The collaboration with Dr. Marques has the potential for reciprocal benefits. Such exchanges in which expertise of poorly known groups is shared across borders will preserve and expand taxonomic expertise, as well as result in joint publications of the results in international, peer-reviewed journals, continued research, and exchange of ideas and cooperative efforts among one another and among future students.