Life Sciences Commons^™

Community Structure Of The Macrobenthos In Back Bay, Virginia, Michael F. Lane

Biological Sciences Theses & Dissertations

A study of the subtidal macrobenthos in Back Bay, Virginia was conducted to examine community structure in relation to sedimentary and water quality characteristics. Samples were collected in August and November of 1987 and February and May of 1988 at ten stations.

Three site groups and three temporal groups were identified by cluster analyses of species abundance. Species composition between site groups was relatively homogeneous and eight species accounted for most of the variation between site groups. A comparison of plots of the biological and physical data in discriminant space suggested that variations in the biological data between site groups …

A Laboratory Study Of Predation On The Trinidadian Guppy, Poecilia Reticulata, By Two Natural Piscine Predators: Effects Of Predator Size, Prey Size, And Habitat Complexity, Hayden Thomas Mattingly

Biological Sciences Theses & Dissertations

Test populations of different-sized guppies, Poecilia reticulata, were exposed to individuals of two natural predatory species, the pike cichlid Crenicichla a/ta and the killifish Rivulus harti, under conditions of varying prey (guppy) density and habitat complexity in the laboratory. Rivulus fed most frequently on newborn and juvenile guppies < 14 mm. Crenicichla consumed more and larger guppies than did Rivulus. The mean guppy size eaten by Crenicichla was dependent on the length of the individual predator, but as a group, the 15 Crenicichla tested were non-selective with respect to guppy size and gender. The prey gender preference of Rivulus could not he determined …

Population Dynamics Of Feral House Mice And Meadow Voles On A Dredge Disposal Site, Georgia E. Kratimenos

Biological Sciences Theses & Dissertations

The population dynamics of two species was studied for one year on Craney Island in Portsmouth, Virginia. This dredge disposal site provided good habitat for the house mouse, Mus musculus, whose opportunistic behaviors can withstand the sudden changes in a dynamic environment. Although the site was not optimal habitat, a population of Microtus pennsylvanicus, the meadow vole, was sustained there. Of the seven species of small mammals captured, 65% were house mice and 28% were meadow voles. Meadow voles were more successful at establishing short periods of residency than were house mice; on average, each meadow vole was …

The Identification, Distribution, And Status Of The Threatened Dismal Swamp Shrew (Sorex Longirostris Fisheri), Thomas M. Padgett

Biological Sciences Theses & Dissertations

Southeastern shrews (Sorex longirostris) were trapped throughout southeastern Virginia and northeastern North Carolina to determine if any morphological characters could

be identified that would aid in the identification and distribution of the threatened subspecies Sorex l._ fisheri, endemic to the Great Dismal Swamp, the more upland nominate subspecies Sorex l. longirostris, and possible intergrades between the two subspecies. Animals were classified a priori into three groups, based on their location of capture. Animals collected from the Great Dismal Swamp National Wildlife Refuge (GDSNWR) and associated bottomland habitats were designated as "fisheri", animals collected farthest from the Swamp as "longirostris", and …

Carnitine Mediated Alterations Of Ethanol And Fatty Acid Metabolism, Randall L. Mynatt

Doctoral Dissertations

The purpose of this dissertation was to examine the effect of dietary carnitine supplementation on ethanol and fatty acid metabolism. Rats were fed Purina chow as such (non-supplemented, NS) or supplemented with 0.5% L-carnitine supplemented CS). Carnitine supplementation for 7d resulted in decreased oxidation of an oral dose of [1-¹⁴C]-ethanol. Expired ¹⁴CO₂ was significantly reduced at hours 4-12 in the CS group. There were no significant differences in urinary excretion of the ¹⁴C-label remaining in tissues after 12h was also not significantly affected by carnitine supplementation. Blood-ethanol concentrations (BEC) were 88.5 and 125.9 mg/dl in …

Nitrogen Dynamics Of The Acacia Senegal Agroforestry System In The Sudan, Zakaria Abdalla Mohammed Saad

Biological Sciences Theses & Dissertations

The savanna is characterized by low rainfall, poor soil and vegetation types dominated by the Genus Acacia. Agroforestry systems evolved, the most notable of which is Acacia senegal agroforestry system (ASAS). It yields gum acacia, fuel and fodder and improved soil N, P, and pH and stability against erosion.

This study investigated the climatic, edaphic and biotic interactions of the ASAS that govern the nutrient dynamics, mainly N, and biomass. The effects of limited resources of soil, space and photoperiod on biomass, nodulation and rate of N fixation were investigated. Genetic differences among populations were studied. Progenies of selected …

The Demographic And Morphological Characteristics Of Black Bears In The Smoky Mountains, Peter Kleppinger Mclean

Doctoral Dissertations

Data on age, sex, body measurements, survival, and reproductive condition were collected from 1702 black bears (Ursus americanus) trapped in the Smoky Mountains (SM), 1972-1989. The age structure suggested a lightly to moderately exploited bear population. Bears of Great Smoky Mountain National Park (GSMNP or Park) were significantly (P = 0.026) older (mean = 4.52 yr) than those of Pisgah (3.86 yr) National Forest (P < 0.076). SM females had a mean minimum reproductive age of 4.2 yr, birth interval of 2.4 yr, and litter size of 2.0 cubs. The percentage of lactating females was significantly associated with age (X² = 20.6, 2 df, P < 0.001), and lactation rates were significantly related to white oak mast production (r² = 0.51, P < 0.01). The annual mortality rate was 26% and was lowest for Park bears (22%) and highest for those of the national forests (30%). Density ranged from 0.09 to 0.35 bears/km², and the intrinsic rate of growth (2-11%) indicated a slightly to moderately increasing population.

Both extrinsic and intrinsic factors govern the population. Food …

Life History, Ecology, And Morphology Of The Ravine Salamander, Plethodon Richmondi, Ronnie D. Jewell

Theses, Dissertations and Capstones

The distribution of P. richmondi and P. cinereus has been of interest to herpetologist for many years. Plethodon cinereus is found throughout the state except for part of the Allegheny Plateau Province where P. richmondi occurs. There is a somewhat abrupt end to their ranges where they overlap which does not appear to be influenced by elevational differences, vegetation patterns, or general climatic changes. The propose of this study was to determine if temperature and/or moisture are limiting the distribution of P. richmondi and P. cinereus in West Virginia. The natural history of P. richmondi has not in West Virginia …

Vegetation Ecology Of Tidal Freshwater Swamps Of The Lower Chesapeake Bay, United States Of America, Richard D. Rheinhardt

Dissertations, Theses, and Masters Projects

Woody and herbaceous vegetation were sampled in 23 tidal swamps along a tidal freshwater tributary of lower Chesapeake Bay. Four vegetative categories were ordinated with Detrended Correspondence Analysis (DECORANA). Species distribution patterns of each strata were compared with respect to edaphic factors, a wetness index, and mean water table depth. Woody species are restricted to hummocks (topographic highs). Hummocks drain as quickly as the tide drops and so are partially inundated for only short periods each day. Although low in canopy diversity, tidal swamps are floristically rich in herbaceous and woody understory species, ranking them among the most speciose in …

Limnology Of Two New Lakes, Mount St. Helens, Wa, Valerie Jean Kelly

Dissertations and Theses

Coldwater Lake and Castle Lake are two new lakes which were formed in the aftermath of the volcanic eruption of Mount St . Helens, WA in May, 1980. This research describes the limnology of these lakes ten years later, and includes physical, chemical, and biological parameters. The two lakes are compared and contrasted. Previous research on the eruption and its aftermath, as well as earlier studies of the lakes are described.

Stock Enhancement Of Caribbean Spiny Lobster, Panulirus Argus Latrielle, Using Artificial Shelters: Patterns Of Survival And Dynamics Of Shelter Selection, David Bryan Eggleston

Dissertations, Theses, and Masters Projects

Field tethering experiments in seagrass beds of Bahia de la Ascension, Mexico examined the impact of different-sized artificial shelters upon survival of three juvenile size-classes of the Caribbean spiny lobster, Panulirus argus. The artificial shelters were concrete structures (casitas) that simulate lobster dens. In the tethering experiments, spiny lobster survival was generally higher in smaller than larger casitas, though the effect depended upon the relationship between lobster and shelter size. Thus, spiny lobster survival depends not only upon the availability of shelter, but also on the scaling between shelter size and lobster size. These results suggest that placement of appropriately-scaled …

Nutrient Standing Stocks And Partitioning In A Forested Coastal Plain Watershed: Groundwater, Stream And Marsh Creek, Sandra A. Hartenstine

Dissertations, Theses, and Masters Projects

No abstract provided.

Factors Affecting Parental Investment Strategies In Male Waterbugs, Scott Kight

Masters Theses

Male giant waterbugs (Belostoma flumineum Say) brood eggs oviposited on their dorsi by conspecific females. Preliminary observations indicate that viable egg pads are sometimes discarded before hatching. Theory predicts that such behavior should occur only if costs incurred by brooding exceed benefits of hatching the egg pad. The amount of paternal investment per pad should be similar for both large and small pad sizes, but as egg pads become smaller, investment per egg increases. Thus, smaller pads should be more likely to be discarded unhatched than larger ones. Similarly, egg pads containing inviable eggs should also be more frequently …

Factors Affecting Survival Of Early Life Stages Of Striped Bass, John Clarke Mcgovern

Dissertations, Theses, and Masters Projects

In 1988 laboratory presentations, bay anchovy, and Atlantic menhaden tested positive as potential predators. Consumption of striped bass larvae by bay anchovy increased at higher prey densities to a maximum of 42 larvae/h at prey densities of 1,650/m&\sp3&. Examination of 229 stomachs of bay anchovy collected during peak spawning in 1988 and 1989 provided direct evidence of predation on striped bass eggs and larvae. The relationship between patterns of survival inferred from the back-calculation of juvenile hatchdates were compared with data sets describing predator and prey fields, egg production, food abundance, and changing environmental conditions during the 1988 and 1989 …

Ecology Of Estuarine Fish Assemblages In Patos Lagoon, Brazil (32 Degrees S), And York River, Usa (37 Degrees N), With Review Of Zoogeography Of Fishes In Western Atlantic Warm-Temperate And Tropical Estuaries, Joao P. Vieira

Dissertations, Theses, and Masters Projects

The first two chapters of this study examine faunal composition and latitudinal patterns in diversity of fishes in warm-temperate and tropical estuarine waters of the western Atlantic from La Plata River (35&\sp\circ&S), Argentina, to Chesapeake Bay (37&\sp\circ&N), USA (33 faunal reports). Species distributions generally corresponded with previously recognized marine zoogeographic regions, and cluster analyses also showed that faunal similarity among estuarine sampling sites was related to the type of sampling gear used and to the type of habitat that was sampled in each estuary. The total number of fish species reported is positively related to the size of the area …