This project explores species boundaries, coevolution, biodiversity, parasite life cycles, and ecology using the cestode (tapeworm) fauna parasitizing the spiny dogfish, Squalus acanthias, and several of its close relatives. One of the aims was to verify the species identity of all the shark specimens from which cestodes were collected. Chapter 1 details use of the elasmobranch "barcoding" gene, NADH2, to verify host identifications, as well as to raise doubt about the wisdom of recognizing the Black Sea population of S. acanthias as a distinct subspecies. Chapter 2 examines diversity in the monotypic cestode genus, Trilocularia, throughout the widespread anti-tropical distribution of S. acanthias (i.e., the North and South Pacific, the North Atlantic, and the Black Sea), and in its congeners. An integrative approach, including morphological (i.e., light microscopy, histology, and scanning electron microscopy) and molecular methods (i.e., 28S, ITS1, 16S genes), was employed. Results reveal a large amount of undiscovered diversity in this genus and suggest that species of Trilocularia may be undergoing speciation more rapidly than their hosts. Chapter 3 describes one of the new species discovered, Trilocularia eberti n. sp. from S. cf. mitsukurii, and provides a prototype for future descriptions of species in this genus. Chapter 4 investigates microthrix variation in Trilocularia from the stomach and the spiral intestine of S. acanthias off Rhode Island. Results suggest that variation seen within a host individual is likely due to developmental changes rather than species differences. Chapter 5 aims to further the understanding of cestode infections in a marine environment through space and time by examining seasonal infection parameters in the cestode community of S. acanthias from Rhode Island across three years. While some general trends may be maintained across disparate localities, spatial variation is likely due to differences in accessibility to intermediate hosts and host diet across sites. The knowledge gained from understanding cestode infections in the vast ocean environment allows us to speculate about the factors driving fluctuations in parasite infections in elasmobranchs.
|Advisor:||Caira, Janine N.|
|School:||University of Connecticut|
|School Location:||United States -- Connecticut|
|Source:||DAI-B 74/09(E), Dissertation Abstracts International|
|Subjects:||Ecology, Evolution and Development, Parasitology|
|Keywords:||Cestodes, Sharks, Species boundaries, Squalus, Tapeworms, Temporal patterns|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be