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Full-Text Articles in Life Sciences
A Multivariate Characterization Of Assemblages Of Planktonic Mysids Decapods And Sergestids In The Chesapeake Bay Mouth Area, John Charles Seibel
A Multivariate Characterization Of Assemblages Of Planktonic Mysids Decapods And Sergestids In The Chesapeake Bay Mouth Area, John Charles Seibel
Biological Sciences Theses & Dissertations
This study is the first to focus on the assemblages of the planktonic mysids, decapods, and sergestids found in the lower Chesapeake Bay. The assemblages of these organisms in the lower Chesapeake Bay and nearby shelf were characterized using three different statistical approaches, and the methods used were evaluated for their effectiveness at delineating ecologically meaningful assemblages. Three stations were sampled across the Chesapeake mouth and one offshore, with oblique and neuston net tows. Twenty-seven larval stages, representing at least 23 species, were found in sufficient numbers to be analyzed statistically. The statistical approaches were each based upon a different …
Differential Utilization Of Allochthonous And Autochthonous Carbon By Aquatic Insects Of Two Shrub-Steppe Desert Spring-Streams: A Stable Carbon Isotope Analysis And Critique Of The Method, Alfred Lynn Mize
Biological Sciences Theses & Dissertations
Stable carbon isotope analysis, a technique that measures the ratio of stable carbon-12 to stable carbon-13 in abiotic and biotic components of ecosystems, was used to assess the differential utilization of autochthonous and allochthonous carbon by aquatic insects of two cold desert spring-streams in the Columbia Basin of Washington State. The aquatic insects of Snively Springs, a heavily overgrown and densely shaded stream, has isotopic values close to that of stream aufwuchs (substrata scrubate) indicating substantial autochthonous carbon dependence. Aquatic insects of Douglas Creek, the more open and less shaded of the two streams, were equally dependent upon autochthonous and …
Seasonal Changes In Brown Adipose Tissue And Pelage Of The Southern Short-Tailed Shrew Blarina Carolinensis, Elisa Michelle Dew
Seasonal Changes In Brown Adipose Tissue And Pelage Of The Southern Short-Tailed Shrew Blarina Carolinensis, Elisa Michelle Dew
Biological Sciences Theses & Dissertations
Winter survival mechanisms in the southern short-tailed shrew, Blarina carolinensis, were studied by examining cellular changes in interscapular brown adipose tissue (ISBAT) and pelage characteristics in specimens collected each month of the year in eastern Virginia. On capture, each specimen was anesthetized with ether and then perfused with a 2.5% glutaraldehyde-2% formaldehyde solution. ISBAT tissues were examined histologically with the transmission electron microscopy. Because BAT is know to produce heat by nonshivering thermogenesis and is more developed in winter animals than summer animals, it was hypothesized that mitochondrial area of BAT would be relatively greater in winter than in summer. …