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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Morphological and molecular analyses of the blacknose dace species complex (Genus Rhinichtys) in a large zone of contact in West Virginia

Smith, Geoffrey D. January 2007 (has links)
Theses (M.S.)--Marshall University, 2007. / Title from document title page. Includes abstract. Document formatted into pages: contains vii, 58 pages including maps. Bibliography: p. 27-30.
2

Intra-specific variation in Rhinichtys c. cataractae (Valenciennes) and Rhinichthys atratulus meleagris (Agassiz) and anatomical and ecological studies of Rhinichthys c. cataractae

Becker, George C. January 1962 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 247-250).
3

Movement of fishes in a network of streams and implications for persistence

Albanese, Brett 20 December 2001 (has links)
Mark-recapture studies sample unevenly over distance and generate biased or distance-weighted movement data, where short distances are sampled more frequently than long distances. I examined how study design affects the degree of distance-weighted sampling and observed movement distributions of stream fish. A modeling study illustrated how distance-weighting increases with the number of mark sites and decreases with the length of stream sampled during recapture. Sub-sampled empirical data sets indicated that longer movements can be detected by increasing the length of the recapture section and that a substantial proportion of fish may move long distances outside of study areas. I also examined factors that were associated with movement in a network of streams. The probability of emigrating from a site was positively related to intermittency and body size and negatively related to distance from the mainstem creek and habitat complexity. Movement rates, measured as the number of fish moving upstream through a trap per day, were positively related to increases in flow, daylength, and water temperature. Distance moved was greater for fish that were initially marked within intermittent reaches. Overall, some species moved in association with several of these factors but others did not respond to any factors. Finally, I identified species-level attributes that were associated with colonization rates after experimental defaunation. Movement rate and abundance explained the most interspecific variation in colonization rates when compared to competing predictors (spatial distribution, body size, and family). Recovery occurred slowly and several species had not restored more than half of their pre-defaunation abundance within a year. Despite slow recovery for some species, defaunation had only a short-term (i.e., < 3 months) effect on relative abundance patterns. This study has important implications for conservation. Improvements in study design will allow detection of longer movements that may be a key component of species invasions, demographic rescue, and colonization. Species that move in association with multiple factors may be better colonists than species that do not. Finally, species that are rare and less-mobile will recover their populations slowly and will be vulnerable to extirpation in systems impacted by frequent pulse disturbances. / Ph. D.

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