Theses and Dissertations from UMD

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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

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Author: search.filters.author.Abraham, EytanSubject: search.filters.subject.Agriculture, Fisheries and Aquaculture

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    STUDIES ON REPRODUCTIVE BIOLOGY AND ENDOCRINOLOGY IN A PRIMITIVE TELEOSTEI, THE AMERICAN SHAD (Alosa sapidissima)
    (2004-07-07) Abraham, Eytan; Zohar, Yonathan; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    American shad is an anadromous fish that displays asynchronous ovarian development. In an effort to enhance our understanding of the reproductive cycle of this primitive Teleostei species, and provide better management tools for the Chesapeake fishery, we have conducted studies of its gonadal and hormonal cycles. We developed various assays to measure reproductive endocrine factors including: 17,20b-dihydroxy-4-pregnen-3-one (DHP) and GnRH. Fish were collected from the Susquehanna River during their spawning migration. One group of fish was sacrificed on site to assess reproductive parameters of wild shad. A second group was transported to a Maryland State hatchery and treated with gonadotropin-releasing hormone agonist (GnRHa) using several delivery systems. These treatments were followed during a two-week period by measurement of various hormonal levels. In addition, fecundity and fertilization of the hatchery groups were measured daily. Our results shed light on the reproductive physiology and endocrinology of the American shad and lay the foundation for usage of GnRHa to induce shad spawning in captivity.