Life Sciences Commons^™

Seasonal Feeding Habits Of The River Otter (Lutra Canadensis) In Ditches Of The Great Dismal Swamp, Ronnie M. Pierce

Biological Sciences Theses & Dissertations

To determine the seasonal feeding habits of the river otter (Lutra canadensis) in the Great Dismal Swamp 209 scats were collected, from May 1977 to May 1978, and analyzed for content. Remains of crayfish were found with a frequency of occurrence of 82% while fish remains occurred in 62% of the scat. This is in direct contrast to previous studies (from other areas) which found fish with a greater frequency than crayfish. Fish consumption was believed to increase during periods of low water or low temperatures. Sunfish were represented most frequently and may be the preferred fish. Amphiuma remains …

Studies On The Anatomy Of The Parasitic Gymnosperm Parasitaxus Ustus (Podocarpaceaea), Evelyn Wilkinson

Biological Sciences Theses & Dissertations

An anatomical study of the parasitic gymnosperm Parasitaxus ustus was conducted. Material was collected in New Caledonia, embedded in paraffin or celloidin, sectioned and stained. The apical meristem consists of apical initial cells, central mother cells, the peripheral zone, and rib meristem. Leaves are scale-like, triangular and broadly decurrent at their bases. Resin ducts and prominent sclereids are present in leaves and the cortex of the stem. The parasite-host connection is in the form of a xylem to xylem connection in which the tracheids are connected by bordered pits.

Swimming As A Determinate To Immigration For Two Small Mammals In Coastal Virginia, Jeffrey Lewis Carter

Biological Sciences Theses & Dissertations

Small mammals were live trapped on the mainland and on an island located in the southeast corner of Virginia. The area was characterized by a mid-Atlantic coastal climate. White-footed mice (Perompsous fsucopus) were trapped on the mainland but not on the island, whereas meadow voles (Microtus psnnsylvimious) inhabited only the island. A series of swimming tests were performed in both the field and in the laboratory on both of these species to determine if swimming abilities could be the factor preventing Pszomysous from colonizing the island.

Both species of small mammals showed good swimming endurance in …

Additional Comments On Reproductive Strategies And Population Fluctuations In Microtine Rodents, Michael S. Gaines, William M. Schaffer, Robert K. Rose

Biological Sciences Faculty Publications

Recently, Schaffer and Tamarin (1973) proposed a model relating changes in reproductive effort (RE) to fluctuating densities in microtine rodents (lemmings and voles). They assumed (and presented data supporting this assumption) that the major effect of increased crowding would be a reduction in survival among prereproductives, thereby lowering the effective fecundity (Schaffer and Rosenzweig 1977) of their parents. As a consequence, Schaffer and Tamarin argued that the optimal reproductive expenditure, E(N), should decline with increasing population size, N. They also deduced the shape of the zero-growth isocline, N*(E), for differing levels of RE and plotted both E(N) and N*(E) on …

Development Of Pelagic Larvae And Postlarva Of Squilla Empusa (Crustacea, Stomatopoda), With An Assessment Of Larval Characters Within The Squillidae, Steven G. Morgan, Anthony J. Provenzano Jr.

OES Faculty Publications

Larvae of the predatory crustacean Squilla empusa were collected from the plankton in Chesapeake Bay and reared in the laboratory to permit description of the pelagic stages before the postlarval stage.

Characters such as rostral length and spinulation, carapace spinulation, relative size of telson, overall body size, and appearance probably are of more value for specific than for generic identification. The presence or absence of teeth on the dactylus of the second maxilliped, the presence or absence of a spine on the basis of the second maxilliped, and the number of epipods may be useful characters in determining generic alliances …

Animal-Sediment Relationship Study Of The Western Branch Of The Lynnhaven River, Charles Perry Seymour

Biological Sciences Theses & Dissertations

The animal-sediment relationships of the marine benthic infauna of an estuarine river system, Lynnhaven River, Virginia Beach, Virginia, were studied at six sites, sampled bimonthly for one year. Six species were found to dominate all of the sampling periods and sites for the year. The greatest number of individuals, biomass, and species were found at the sand sites. Deposit feeders were recorded in greater number than suspension feeders at both the sand and the mud sites.

Cluster and nodal analyses were successful in demonstrating animal-sediment relationships for the intertidal regions of the river system.

A Potential Macroregulatory Mechanism For Growth Regulation In Neurospora Crassa, Martha Mooney

Biological Sciences Theses & Dissertations

Neurospora produces a phase specific, cationic mucopolysaccharide composed primarily of galactosamine (GAG-MP) which becomes part of the cell wall and is later secreted into the media. Its appearance coincides with the onset of the restricted phase of growth and causes efflux of small molecular weight metabolites when incubated with conidial cells. This activity may be a product of electrostatic interactions of the GAG-MP with the conidial plasma membrane. The activity is blocked by acetylation of the primary amines on the molecule, digestion by enzymes that hydrolyze carbohydrate linkages and the inclusion of NaCl (lM) in the GAG-MP/conidia reaction mixture. The …

The Fall And Winter Food Habits Of The Black Bear (Ursus Americanus) In The Great Dismal Swamp Of Virginia, Francis Leonard Daniel

Biological Sciences Theses & Dissertations

A study was conducted on the food habits of the black bear (Ursus americanus) in the Great Dismal Swamp of Virginia. A total of four stomachs and 42 scats were analyzed. Four samples were collected from September and October of 1975, and the remainder of the samples were collected from September 1976 to February 1977. The study was conducted to obtain information vital to the management of this species in the Great Dismal Swamp. Vitis spp. was the primary food item during the fall comprising 43% of the total diet, followed by fruits of Diospyros virginiana and Asimina triloba, each …

Mercury, Copper, And Zinc In Selected Ichthyofauna Of Lower Chesapeake Bay And Hampton Roads, Virginia, W. Bruce Aitenhead

OES Theses and Dissertations

Anchovys, croaker, spat, summer flounder and hogchokers were collected monthly to seasonally from November 1972 to October 1973 at three locations in the southern Chesapeake Bay region of Virginia.

The concentrations of mercury, copper and zinc were determined by atomic absorption spectrophotometry in whole fishes. Metal concentration varied with species and location. Anchovys had the highest mean concentrations of mercury and zinc while hog- chokers had the highest mean copper concentration. Mercury levels exceeding O.5 ppm were observed in species from all three loca- tions, but maximum heavy metal concentrations per species were highest in Craney Island fishes.

Temporal variations …

The Photosynthetic Action Spectra Of The Phytoplankton And Their Role In Governing Spatial And Temporal Distribution: A Numerical Modeling Approach, William Morrow Willis

OES Theses and Dissertations

In the present study a numerical modeling approach is employed to examine the role of division spedific differences in photosynthetic action spectra in governing the relative size of diatom and dinoflagellate carbon synthesis along various marine light regime gradients. A radiative transfer model taking into account both Rayleigh and Mie atmospheric optical properties is employed to define the light regime incident on the sea surface. The hydrospheric light regime is defined by an exponential decay model with a correction for diffuse back scatter. Taken together, the atmospheric and hydrospheric models define the spectral composition and intensity of light in the …

Herbaceous Production In Burned-Cut Burned-Uncut And Control Areas Of A Chamaecyparis Thyoides (L.) Bsp (Cupressaceae) Stand In The Great Dismal Swamp, Caroline Elisabeth Mckinley

Biological Sciences Theses & Dissertations

The herbaceous layer of an Atlantic white cedar (Chamaecyparis thyoides) stand in the Great Dismal Swamp was sampled to estimate the productivity of two burned areas and a control area. The herbaceous vegetation was sampled along three transects utilizing the harvest method and productivity values were estimated using peak biomass values for each individual species. The burned-cut area had the highest productivity (3623 kg ha^-l yr^-1) and was characterized by species of the Asteraceae, Poaceae, and Cyperaceae. The burned-uncut area had a productivity value of 1636 kg ha^-1 yr^-1 with similar species of the Asteraceae …

The Reproductive Cycle Of Microtus Ochrogaster In Eastern Kansas, Robert K. Rose, Michael S. Gaines

Biological Sciences Faculty Publications

About 800 Microtus ochrogaster were live—trapped at biweekly intervals from May 1971 through March 1973 in 3 grassland study areas in eastern Kansas, USA. Details of reproduction were determined by autopsy. Population density increased through the first winter, reached a peak in April 1972, then declined sharply during that summer and beyond. Body length, but not body mass, tended to be positively related to density. Both sexes matured at about the same weight; development was somewhat prolonged during the winter months, especially in the winter preceding the population peak. Pregnancy rates were high, approaching maximal iteroparity, throughout the study, with …

Description Of The Larval Development Of Squilla Empusa Say (Crustacea Stomatopoda) With Aspects Of Larval Ecology In Chesapeake Bay, Steven Gaines Morgan

OES Theses and Dissertations

Larvae of Sguilla empusa were collected from the plankton and were reared in the laboratory to describe the pelagic larval development and the postlarval stage. Nine pelagic stages are passed through before the postlarval stage is attained.

The larvae reared for descriptive purposes were subjected to sixteen combinations of temperature and salinity to determine their tolerance to the two parameters. Larvae survived longer and molted more frequently when reared at 25°/oo and 20°C or 25°C, which corresponds to the natural conditions of the Chesapeake Bay when the larvae were collected.

A three year planktonic survey conducted in the lower region …

Plant Distribution And Succession Within Interdunal Depressions On A Virginia Barrier Dune System, Robert Wayne Tyndall

Biological Sciences Theses & Dissertations

A unique series of interdunal depressions was recognized on the barrier dune system of southeastern Virginia. Plant distribution and succession, and environmental factors controlling them, were studied in the series. Plant community distribution appears to be predominantly controlled by soil moisture, interspecific competition, and feral hog disturbance. Both biotic and physiographic succession are apparent with Quercus virginiana probably climax for both. Salt spray and feral hog and migratory waterfowl activity are important controlling factors of plant succession. Results indicate that the zonal appearance of shrubs and trees on the Virginia and North Carolina coasts is due to the absence of …

The Effects Of Temperature And Salinity On The Larval Development Of The Grass Shrimp, Palaemonetes Pugio Holthuis Reared In The Laboratory, William Ray Floyd Iii

OES Theses and Dissertations

Palaemonetes pugio larvae, obtained by induced breeding of adults collected in the late fall of 1975 from the Lafayette River, Norfolk, Virginia, were reared in the laboratory using a six temperature by seven salinity factorial design in order to determine the effects of these factors on larval development. Test conditions involved temperature levels ranging from 10°C to 32.5°C and salinity levels from 5°/oo to 35°/oo. At each temperature-salinity condition, 36 larvae were reared individually in 25 ml of artificial seawater containing 25 mg/kg of polyethylene oxide. Food consisted of Artemia nauplii at a concentration of 30/ml of culture water. From …

A Seasonal Study Of Phytoplankton Composition Abundance And Productivity In Back Bay, Virginia, Robert Ringgold Comegys

Biological Sciences Theses & Dissertations

Phytoplankton samples were collected monthly (August 1974-June 1975) at two stations in the Back Bay system of southeastern Virginia. Measurements of phytoplankton productivity and potentially influencing environmental parameters (water and air temperature, turbidity, depth, pH, salinity, dissolved oxygen) accompanied sample collections. A total of 106 phytoplankton species, representing six algal divisions and 54 genera were identified. Cyanophyta species were dominant at both stations in the warmer months of August, September, October, and June, and in April at one station only. In all remaining months, Chlorophyta species were dominant, indicating a seasonal shift in phytoplankton composition during winter and spring. The …

Contributions To The Reproductive Biology And Natural History Of The Pirateperch, Aphredoderus Sayanus, Edward O. Murdy

Biological Sciences Theses & Dissertations

The purpose of this study was to describe the micro and macro-anatomy of the reproductive system and the testicular and ovarian development in Aphredoderus sayanus.

Specimens were collected at least once a month from September, 1976, through May, 1977, in Cypress Pond, a part of the Dismal Swamp drainage, outside of Suffolk, Virginia. Forty-three specimens had their gonads examined histologically, of these 13 were males, 29 were females and in one specimen the sex was not determinable.

Aphredoderus sayanus is a spring spawner, spent gonads were found on and after April 13, 1977. Gonads began to ripen in the …

Demonstration Of Unique Mycelial Components In Candida Albicans, David Jon Mancuso

Biological Sciences Theses & Dissertations

Mycelial (M) and blastopore (B) cell homogenates of Candida albicans strain BJ85 were compared to detect and recover unique M components. Qualitative differences in the protein and lipid content of Mand B homogenates were suggested by discontinuous polyacrylamide gel electrophoresis (DPAGE). In addition, a quantitative and possibly qualitative shift in the protein content during germ tube formation was implied by DPAGE. Unique M components were detected using both DPAGE and immunoelectrophoretic (IE) techniques. One unique M component by DPAGE, four by IE, and two by combined DPAGE and IE techniques were suggested. Of these three methods, only DPAGE and the …

Effect Of Nitrite And Nitrate On The Larval Development Of The Grass Shrimp Palaemonetes Pugio Holthuis, Carl Bingham Hinesman

OES Theses and Dissertations

The effects of nitrite and nitrate on survival and larval development of the grass shrimp Palaemonetes pugio were investigated in the laboratory. Nitrite concentrations assayed were 0 (control), 0.5, 1.0, 10, 25 and 50 mg NO₂/1. Nitrate concentrations tested were 0 (control), 100, 250, 500, 1000 and 2000 mg NO₃/1. Temperature and salinity conditions were 25 C and 25 ‰, respectively, and all tests occurred in the dark. Thirty-six larvae were reared in each assay, twelve from each of three adult females.

Nitrite levels of'5 and 50 mg NO₂/1 significantly reduced survival of larvae …

A Baseline Study On The Possible Mechanisms Of Larval Stomatopod Distribution On The Carolina Shelf, Carl Robert Berman Jr.

OES Theses and Dissertations

The South Carolina Marine Resources Institute provided the author with 198 station samples containing 2,193 stomatopod larvae. These larvae had been collected during ichthyoplankton Bongo tows on five separate cruises aboard the Institute's vessel R/V DOLPHIN (February, 1972 to January, 1975). The larvae were examined microscopically and divided into early, middle, and late stages according to known growth criteria. The larval distribution was plotted geographically, by seasons, and larval density (larvae/m3) was graphed against distance offshore. Using these data, together with the circulation characteristics on the Carolina Shelf, significant distributional data appeared which supported the hypothesis that the stomatopod population …

Temperature And Salinity Tolerance Of The Larvae Of The Sand Shrimp, Crangon Septemspinosa (Say), Karen Lyttle Hinsman

OES Theses and Dissertations

The effects of temperature and salinity on the larval development of the sand shrimp, Crangon septemspinosa, were investigated in the laboratory using 30 combinations of temperature and salinity in a five by six factorial experiment. The five temperatures were 5°c, 10°c, 15°c, 20°c, and 25°c and the six salinities were 10°/oo, 15°/oo, 20°/oo, 25°/oo, 30°/oo and 35°/oo. Thirty-six larvae were used for each temperature-salinity combination. Temperature and salinity produced significant differences (1% level) in survival and the duration of larval development. Highest survival occurred at 15°c and 20°/oo. At optimum temperatures (15°c to 20°c) larvae exhibited the broadest tolerance …

Live Trap Preference Among Grassland Mammals, Robert K. Rose, Norman A. Slade, James H. Honacki

Biological Sciences Faculty Publications

In two independent studies, small mammals of grassland communities in eastern Kansas, when given a choice, preferred Fitch to Sherman live traps. Except for the harvest mice in the demographic study, the type of preferred trap and magnitude of selection was remarkably comparable, with microtines showing slight, and cricetines strong, preferences overall. The merits of each type of trap are compared, and related to season, weather, prior experience, and trap-associated mortality.

Feeding Ecology Of Black Sea Bass Centropristis Striata On An Artificial Reef Off Virginia (Perciforms: Serranidae), Ping K. Chee

OES Theses and Dissertations

The feeding ecology of the black sea bass, Centropristis striata, associated with artificial reefs shows seasonal and size-related changes. Monthly collections totaling 520 black sea bass taken from an artificial reef near the Chesapeake Light Tower, Virginia, between August 1975 and May 1976, were analyzed for food habits as revealed by number, volume, frequency of occurrence and a modified Index of Relative Importance.

The black sea bass feeds on the artificial reef as well as the adjacent areas. When food was abundant on the reef, food items from the reef and the surrounding area were consumed. Upon depletion of the …

Duck Plague Virus An Investigation Of Cytopathic Effects, In-Vitro Host Range, And Inhibition By Phosphonoacetic Acid, Ronald Attanasio

Biological Sciences Theses & Dissertations

Duck plague is a hemorrhagic, necrotic disease found exclusively in the order Anseriformes, family Anatidae (ducks, geese, swans). The etiologic agent has been reported to be a herpes-like virus. The Holland strain of duck plague was found to induce cytopathic effects in cell culture (perinuclear vacuolation followed by lysis). A simple reproducible plaque assay for quantitating the virus was developed. Under conditions of the plaque assay, one-hit kinetics were observed. The host range of duck plague virus in cell culture was found to include the order Galliformes, family Phasianidae (pheasants, quails and partridges). Duck plague virus-induced cell culture cytopathic effects …

Effect Of The Chesapeake-Elizabeth Sewage Outfall Virginia Beach, Virginia On The Distribution And Ecology Of Benthic Foraminifera, James M. Bates Jr.

OES Theses and Dissertations

Sediment and bottom water samples from seven stations at the Chesapeake Elizabeth sewage outfall, Virginia Beach, Virginia were collected in order to evaluate the effect of the outfall on benthic foraminifera. The top centimeter of sediment was analyzed for living and total (live plus dead) foraminiferal densities, chlorophyll a, sediment grain size, ATP, percentage of silt and clay, and total organic carbon. Bottom water salinity, temperature, and ammonia were also analyzed.

Living foraminiferal density increased from March to July and with distance from the outfall. Total foraminiferal density also increased from March to July. The set of environmental variables was …

A Comparative Study Of A Salt Water Impoundment With Its Adjacent Tidal Creek Pertinent To Culture Of Crassostrea Virginica (Gmelin), William D. Anderson Iii

OES Theses and Dissertations

Certain physical, chemical and biological characteristics associated with the culture of subtidal Crassostrea virginica were assessed in a salt water impoundment and its adjacent tidal feeder creek. Large seed oysters (initial y = 57.3 mm) were transferred from a somewhat polluted estuary of Charleston Harbor to floating, mid-water, and bottom hardware cloth trays (200/tray) in a four hectare pond. Identical trays at comparable depths were placed in the tidal creek and each location was sampled monthly for growth and survival. Surface and bottom water samples were collected weekly throughout the study and hourly during four seasonal 25 hour stations. Standard …

The Food Habits Of Ictalurus Natalis, Centrarchus Macropterus And Perca Flavescens In Lake Drummond In The Dismal Swamp Of Virginia, Steven C. Russell

Biological Sciences Theses & Dissertations

The food habits of yellow bullhead catfish (Ictalurus natalis), yellow perch (Perea flavescens), and fliers (Centrarchus macropterus) in Lake Drummond in the Dismal Swamp were examined. Seventy yellow bullheads (42 mm to 255 mm), 136 yellow perch (41 mm to 280 mm), and 110 fliers (81 mm to 140 mm), were collected with gill nets, traps, seins, and electro-fishing gear from June through November of 1975. Frequency of occurrence and volumentric data were used to evaluate the relative importance of food items. Spearman's rank correlation coef­ficient was determined from the data to test differences …

An Investigation Of The Nucleotide Cyclic 3'5' Adenosine Monophosphate In Young Hypocotyls Of Pisum Sativum L., Gary Marsh Hilton

Biological Sciences Theses & Dissertations

Concentrations of cAMP increased with time in pea hypocotyls assayed at 24 hour intervals over a period of four days. The highest concentration was 20.1 pmoles/mg protein which occurred in 96 hour hypocotyl tips. Ninety-six hour root bodies (dissected region between tip and embryo) achieved a concentration of 8.6 pmoles/mg. Concentrations of cAMP in embryos remained constant around one pmole/mg for three days and values doubled on the fourth day.

Hypocotyls, after germination for 72 hours, were dissected and incubated for various lengths of time in water and 3xl0^-8M IAA. Tips incubated for two hours showed a tenfold …

Studies Of The Purification Of Nad-Dependent And Nadp-Dependent Isocitrate Dehydrogenase By General Ligand Affinity Chromatography, Geoffrey H. Bertkau

Chemistry & Biochemistry Theses & Dissertations

Purification of Yeast NAD⁺-dependent isocitrate dehydrogenase was partially successful when utilizing an NAD⁺-ribosyl-hydrazide Sepharose affinity chromatography column. Although no specific elution system was found, a maximum purification of sixty-five fold was achieved with 0.5M KCl elution. A 38-fold purification was obtained when 20mM NAD⁺ was employed for elution.

Yeast and calf liver NADP⁺-dependent isocitrate dehydrogenase were also found to bind to NAD⁺-ribosyl-hydrazide Sepharose as well as the NAD⁺-dependent enzyme. Again, elution was achieved with either o,5M KCl or 20 mM NADP⁺.

Ammonium sulfate fractionation decreased the yield …

Kinetic And Binding Studies On L-∝-Glycerophosphate Dehydrogenase, Paul Richard Rosevear

Chemistry & Biochemistry Theses & Dissertations

The properties of the coenzyme, NAD, binding site of chicken muscle L-∝-glycerophosphate dehydrogenase were studied. Adenosine monophosphate, adenosine diphosphate and adenosine diphosphoribose were sha.vn to inhibit the enzyme competitively with respect to NAD. The presence of adenosine, pyrophosphate and ribose regions in the coenzyme binding site of the enzyme was suggested by the inhibitor constants obtained for these compounds.

Disodium monoalkyl phosphates, n-butyl to n-dodecyl phosphate, inclusive, were also shown to inhibit the L-∝-glycerophosphate dehydrogenase catalized reaction competitively with respect to NAD. A positive chain length effect was observed in the binding of these compounds to the enzyme, suggesting the …