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

University Of Connecticut, Storrs CT

Investigators

Abstract

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.