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

根据目前已知的情况，南美淡水黄貂绦虫的多样性和宿主特异性似乎比它们的海洋同类小得多。然而，新的数据表明，可能有比之前认为的更多的物种，而且每个绦虫物种可能都高度特定于其黄貂鱼宿主物种。本项目运用分类学和系统化的工具对这一问题进行研究。作为这项研究的基础的绦虫标本包括保存在博物馆的标本，以及最近野外收藏的标本。具体地说，将调查两个属或两组绦虫物种。在秘鲁从新的地点和黄貂鱼宿主收集的绦虫将用以前没有在该小组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通过DNA序列数据得到加强。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。对绦虫之间进化相关性的测试将作为一个分析框架，以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，以及南美淡水黄貂绦虫的起源。这项工作将阐明绦虫和黄貂鱼宿主的淡水和海洋系统是否存在根本差异。这项研究有可能产生有用的信息，并适用于未来的研究，重点是进化生物学、分类学、生物地理学、生物多样性、生态学和保护。对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，也有助于在原产国更容易获得有关生物多样性的知识。标本被存放在收集它们的国家的博物馆里，这些标本可以供世界各地的科学家以及初学者研究和分析。与马奎斯博士的合作有可能带来互惠互利。这种跨国界共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门知识，并导致在国际同行评议的期刊上联合发表结果，继续研究，彼此之间和未来的学生之间交流思想和合作努力。

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.