Biology Commons^™

Discharge Responses Of The Nematocysts Of The Stinging Nettle Chrysaora Quinquecirrha To External Stimuli, Christa Merz Hubbard

Master's Theses

Chrysaora quinquecirrha nematocysts and isolated in suspension were systematically exposed to a wide range of chemical and mechanical stimuli to determine which ones would initiate discharge.

Nematocysts in situ were found to be highly responsive to stimuli and showed well-marked, immediate discharge when treated with acid, base and electrical stimuli. Slight discharge occurred with salt solutions, beef extract, beef extract and contact, human hair and change in temperature.

Discharge increased with the concentration of the reagent or the strength of the mechanical stimuli. A significant increase in discharge occurred in isolated nematocysts treated with HCl, acetic acid and sodium hydroxide. …

The Effects Of The Toxins Of Lophopodella Carteri (Ectoprocta) On The Blood Gas Properties Of The Bluegill Lepomis Macrochirus, Robert Allen May

Master's Theses

Lepomis macrochirus (bluegill) were exposed, in small containers, to homogenates of Lophopodella carteri, an ectoproct that contains substances toxic to gilled vertebrates. Blood pH, pco₂, and po₂ were determined with a blood gas analyzer. Blood carbonic anhydrase activity was measured manometrically.

The ectoproct toxins caused significant decreases in blood pH and po₂ and a significant increase in blood pco₂ and carbonic anhydrase activity. It is proposed that these changes in blood properties were initiated by a film of mucus covering the gill epithelium. The secretion of mucus is thought to be a response to irritation …

A Comparative Study Of Fish Populations In The Vicinity Of A Thermal Discharge In The James River, Virginia, Judson Wayne White

Master's Theses

The size, species composition and structure of fish populations in a six mi stretch of the James River in the Piedmont Province of Virginia were analyzed. Twenty collections were made by electrofishing from October 1972 through September 1973 from both the north side of the river, which received a thermal discharge from a power station, and the south side where temperatures were ambient. Parameters investigated were number of species, total number of individuals and the Shannon-Wiener and evenness indices of species diversity. Significant differences in seasonal patterns were found between the communities in the thermal discharge and those on the …

In Vitro Effects Of Prolactin, Cortisol, Aldosterone, And Cyclic Amp On Branchial Na+, K+ - Activated Atpase Of The Killifish, Fundulus Heteroclitus, Stephen Burke Kerby

Master's Theses

In vitro effects of prolactin, cortisol, aldosterone, and cyclic adenosine monophosphate were studied on branchial Na+, K+ - activated ATPase of freshwater adapted killifish, Fundulus heteroclitus. Decreases in ATPase activity were found after treatment with prolactin and aldosterone. Cyclic AMP caused an increase in ATPase activity. The action of cortisol on this enzyme was not clear.A dose - response relationship was found only for cyclic AMP .It is proposed that cyclic AMP may be involved in the adaptation of F. heteroclitus to seawater.

Changes In The (Na+ K+) - Dependent Atpase Activity In Gills Of The Euryhaline Teleost, Fundulus Heteroclitus, Upon Adaptation To Freshwater And Salt Water As Determined By Specific Activities And 3h - Ouabain Binding Sites, Mary Elizabeth Gilman

Master's Theses

Previous attempts to measure the (Na⁺+K⁺) - dependent ATPase in gills of euryhaline teleosts have yielded controversial results. In this study both the (Na⁺+K⁺) - dependent ATPase activity and the number of JH - ouabain binding sites, representing the number of ATPase molecules, were measured in gill tissue preparations of the killifish, Fundulus heteroclitus. The (Na⁺+K⁺) dependent ATPase activity and ouabain binding sites were greater in gills of fish fully adapted to freshwater than in those adapted to salinities of 17 ppt or 24 ppt. On the other …

Predicting Primary Productivity In Westhampton Lake, Richmond, Virginia., Gary Newton Moore

Master's Theses

Several predictive photosynthetic models were tested using light, temperature, nutrient, chlorophyll, and primary productivity data collected from Westhampton Lake, Richmond, Virginia from February-September, 1972. A simple linear model, the Kendall rank correlation coefficient, was used to relate photosynthesis to individual meteorological, physical, chemical, and biological factors. iii Of the parameters measured, only the daily maximum photosynthetic efficiency ((P/chl) max ) was significantly correlated with photosynthesis. Five multiple factor (non-linear) models were tested. In the best fitting model, primary productivity was a function of the maximum observed ratio of photosynthesis/chlorophyll concentration, light intensity, temperature, nutrient concentrations, and chlorophyll concentration. The Pearson …

Effects Of Temperature And Ph On The Growth And Composition Of The Sporophyte And Gametophyte Generations Of Allomyces Arbusculus Butler (1911), Lawrence Wayne Lenz

Master's Theses

Pure cultures of the sporophyte and gametophyte generations of Allomyces arbusculus Butler (1911) were grown under varied conditions of temperature and pH. On solid media the gametophyte did not grow at 10 and 15 C; the sporophyte began slow growth after a long lag period at 15 C. There were no significant differences in growth between the sporophyte and gametophyte at 20 and 25 C. Increasing colony areas occurred for both generations at temperatures between 30 and 40 C, with the largest amount of growth for either generation at 35 C.

Colonies grown in broth media at various pH levels …

The Nature Of Miniature Melanocytes In Murine Epidermis, John Thomas Earnhardt

Master's Theses

In the epidermis of PET/Wmr mice the population of melanocytes reaches a peak and begins to decline during the first postnatal week, and has disappeared within four weeks. During this period a small number of weakly DOPA reactive miniature melanocytes are seen dispersed among the generally large, highly DOPA reactive melano­cytes typical of the animal. These miniature melanocytes appear early, are among the last to disappear, and their population remains relatively constant against the drastically changing population of typical melanocytes. In attempts to determine the nature of the miniature melanocytes, heterologous grafting was employed whereby the melanocytes were subjected to …

Evidence For An Ambidirectional Magnesium-Activated, Sodium-Potassium Dependent Adenosine Triphosphatase, John Dale Hempel

Master's Theses

Controversy exists as to whether the Na-K ATPases of euryhaline fishes are the same enzyme.This study demonstrates that the phosphorylated enzyme from gills of Fundulus heteroclitus adapted to freshwater and salt water migrate to the same position in SDS polyacrylamide gels. Similar behavior of the enzyme from both sources in different ionic media is also shown. Additionally, the possible ability or the enzyme to couple an osmoregulatory influx to an excretory efflux in freshwater fish is demonstrated. The term "ambidirectional" is proposed for this enzyme, and its place in certain membrane models is discussed.

The Effects Of Ultraviolet Irradiation On The Pigment Cells Of The Pet/Wmr Mouse Epidermis, Vaughan Henry Howard Jr.

Master's Theses

Epidermal melanocytes in mammals are known to occur in a variety of shapes, sizes, and colors. The basic melanocyte morphology is dependent upon genetics, but there are a number of environmental factors that can cause modification.

In the epidermis of PET/\vrnr mice, the population of rnelanocytes reaches a peak and begins to decline during the first post-natal week, and has disappeared within four weeks. Dispersed among the large, highly DOPA-reactive melanocytes are miniature melanocytes. These miniature melanocytes are weakly DOPA-reactive and appear early in the post-natal period. The miniature melanocyte population is relatively constant and these miniature cells are among …

Ddt Inhibition Of (Na+, K+)-Activated Atpase In Gill Tissue Of Fundulus Heteroclitus, Nancy Mccutcheon Slate

Master's Theses

The DDT inhibition of (Na+, K+) - activated ATPase in gill preparations of the euryhaline teleost, Fundulus heteroclitus, was measured. The (Na+, K+) -activated ATPase was found to be sensitive to DDT, with 74.6% of the enzyme's specific activity inhibited by 20 ppm DDT. The (Mg++)-activated ATPase was also sensitive to inhibition bv DDT but not to the extent of the (Na+, K+) - activat ed ATPase . Due to previous work which showed that DDT antagonized valinomycin-induced K+ conductance in a synthetic membrane, the effect of K+ on DDT inhibition was examined kinetically. The Km for K+ in gill …

Isolation And Identification Of The Toxic Principle In The Tissues Of The Ectoproct Lophopodella Carteri (Hyatt), Donald Coleman Smith

Master's Theses

The tissue of Lophopodella carteri (Hyatt) was isolated, and the agent toxic to fish present in the tissues was extracted. A chloroform-soluble component and a water-soluble component were separated from the filtrate of the homogenized tissues. Each component was tested for toxicity. The chloroform-soluble component was found to be extremely toxic. The water-soluble component was originally non-toxic, but after several months of freezing and defrosting the tissue, this component became toxic.

The chloroform-soluble component was purified by thin-layer chromatography. Several lipid classes were obtained, of which one was toxic. This toxic class was further purified by thin-layer chromatography resulting in …

The Effects Of Estradiol And Thyroxine On The Plasma And Liver Proteins Of The Thyroidectomized Water Snake, Albert D. Morrongiello

Master's Theses

The effects of thyroidectomy, estradiol treatment, and thyroxine treatment on plasma and liver protein concentrations in the water snake, Natrix fasciata fasciata (Linnaeus, 1766), were investigated. There was a significant lowering of liver protein concentrations following thyroidectomy. This deficit could be replaced with thyroxine alone, but could not be replaced by treatment of thyroidectomized snakes with estradiol alone or with a combination of estradiol and thyroxine.

The plasma resolved into nine plasma proteins when electrophoresed in polyacrylamide gels. Although thyroidectomized snakes treated with estradiol only or a combination of estradiol and thyroxine showed enhancement in two protein fractions, the significance …

The Role Of The Adrenal Gland In The Survival Of White Rats Subjected To The Parotid Toxin Of The Toad, Bufo Marinus, Mark A. Green

Master's Theses

Six groups of white labor atory rats were utilized in this experiment. A sham-operated group and an adrenalectomized group were used as controls. Four other groups were adrenalectomized and given replacement therapy of cortisone, deoxycorticosterone acetate, epinephrine, and norepinephrine. All groups were then given injections of toad toxin from the parotid glands of Bufo marinus. Their heart and breathing rates were recorded for 60 minutes.

All of the untreated adrenalectomized rats showed altered heart and breathing rates and were killed by the toxin. Cortisone and nor ­ epinephrine aided the adrenalectomiz ed rats to survive. but cortisone was the …

Spacing And Orientation Of The Siphons Of The Tunicate, Styela Plicata, Alfred Page Chestnut

Master's Theses

The spacing and orientation of sipons of Styela plicata (Lesueur)in swift and slow currents were examined. Within aggre­ crates, the siphons were spaced farther apart in slow currents than in swift currents. The siphons were not horizontally oriented but were vertically oriented in slow currents. The adaptive values of spacing and orientation under different currents are discussed.

Quantitative Growth Relationships Of Microcoleus Vaginatus (Gom.) Ex Drouet And Alcaligenes Sp. In A Sucrose-Salts Medium, James Rexford Brownell

Master's Theses

The blue-green alga, Microcoleus vaginatus (Gom.) ex Drouet 1968, and a bacterium, Alcaligenes sp., collected from the same habitat, were cultured together and separately in mineral salts media with and without sucrose. Growth of axenic M. vaginatus was stimulated by sucrose. In association with the bacterium in sucrose-containing media algal growth was suppressed, while in inorganic media it was stimulated. Factors involved in this algal-bacterial system probably included competition for the carbon source, changes in pH, and accumulation of cellular waste and lytic products.

An Electrophoretic Comparison Of The Gill Plasma Membrane Proteins Of Freshwater And Saltwater-Adapted Killifish, Fundulus Heteroclitus, Earl Dean Hammit

Master's Theses

A study was undertaken to compare proteins present in the gill membranes of freshwater and salt­ water adapted killifish, Fundulus heteroclitus. For this purpose, a method for the preparation or gill plasma membranes was developed. Polyacrylarnide gel electrophoresis indicated that the two types of gills possessed many membrane proteins in common. However, the freshwater adapted group possessed a single protein not found n the saltwater adapted group and the latter contained a protein not found in the freshwater adapted group.

A Survey Of Fresh-Water Oligochaeta And Their Commensal Ciliates From The Richmond, Virginia Area, Elsa Queen Falls

Master's Theses

The distribution of North American aquatic oligochaetes and the ciliates inhabiting their guts have received very limited attention. For this reason, the present study was initiated to survey fresh ­water oligochaetes of the families Aeolosomatidae, Naididae, Opistocystidae, and Lumbriculidae in four bodies of water of the Richmond, Virginia area and to determine the incidence of commensal ciliates within the gut .

Intestinal Absorption And Lipolysis Of Safflower Oil And Other Unsaturated Vegetable Oils In Rats, Robert Leslie Gregory

Master's Theses

The intestinal lipolysis and absorption of safflower, corn, peanut, olive, cottonseed and soybean oils were studied in the rat. Oils and pancreatic lipase were injected into the rat jejunum and ileum (ligated in situ), and the amount of esterified fatty acids absorbed and free fatty acids present in the gut after 3 hours was determined.

Safflower oil was absorbed significantly less than the other oils. There was no significant difference between the absorption rates of the other oils. When the oils were subjected to porcine pancreatic lipase in vitro, safflower oil also exhibited the lowest rate of hydrolysis.

The rates …

A Comparative Study Of Solubilized Proteins From Phycomyces Blakesleeannus By Disc Electrophoresis, Douglas Burton Gillespie

Master's Theses

Mycelial, sporangiophore, and zygospore solubilized protein fractions o Phycomyces blakesleeanus Burgeff were separated on polyacrylamide gels and stained. Protein patterns of 8 and 13 day old mycelia of the + strain were identical as were the patterns of the same two age groups of the - strain. The + mycelia exhibited 9 protein bands while the - strain contained 10 bands. Seven bands were homologous to both strains. Sporangio­phore samples of 5 and 10 day old cultures from + and - strains contained 4 protein bands homologous to all 4 samples. The protein band at 9 mm was also …

The Induced Differentiation Of Mouse Ectoderm To Epidermis By Growth On Freeze-Thawed Dermis, Albert Joseph Banes

Master's Theses

Previous investigators have grown or maintained adult or embryonic skin in tissue culture and on the chorioallantoic membrane (CAM) of chickens. These studies have revealed two important factors involved in culturing skin: (1) the presence of an inducer which originates in the dermis and affects the phenotype of epithelial cells; and (2) the influence of the physical surface of the substrate on which epidermis is cultured.

The current investigation presents evidence that ectoderm from the limb buds of 10 to 12 day-old mouse embryos can form an epidermis when combined with dermis killed by alternate freezing and thawing, and cultured …

A Determination By Thin-Layer Chromatography Of The Chemical Nature Of The Poison Produced By The Bryozoan Lophopodella Carteri (Hyatt), John Michael Dolan

Master's Theses

A study was undertaken to isolate and characterize by thin-layer chromatography the poisonous principle produced by the freshwater bryozoan, Lophopodella carteri (Hyatt).

The bryozoan homogenate was divided into a lipid and non-lipid portion and each was assayed for toxicity. Only the lipid extract was lethal to fishes. The lipid part was divided into six classes by thin-layer chromatography. When tested, four of the six classes were toxic. Thin­ layer chroatography was used to subdivide each class into fractions. Assays showed toxicity in nine of fourteen fractions.

Evidence indicates that the poisonous princi ple is a lipid and the large number …

Comparative Age And Growth Of Two Darters, Percina Peltata (Stauffer) And Percina Notogramma (Raney And Hubbs), In Virginia, Garnett William Link

Master's Theses

Two closely related species or darters, Percina peltata and Percina notogramma, occur sympatrically in Virginia. An analysis or the number of scale annuli and standard length measurements on 447 peltata and 195 notogrannna revealed four year classes in both species, with very few individuals surviving to III-year class. Both species had approximately 1:1 sex ratios after the first year, in which males were predominant. The growth of both species was approximately the same after the first year; however peltata, the larger species, apparently gains an advantage during the first year which it never loses. The sexes did not …

The Effects Of Estradiol And Growth Hormone On Liver And Plasma Protein Of The Hypophysectomized Water Snake, Terry Chong Der

Master's Theses

The effects of estradiol and ovine growth hormone (GH) on liver and plasma protein of hypophysectomized Nat rix fasciata (southern banded water snake) were investigated. Liver and plasma protein concentrations were determined colorimetrically end expressed a mg/gm wet weight tissue.

Significant increases in liver protein levels occurred 48 and 7 hours after a single injection of estradiol in hypophysectomized animals. A single injection of GH had a like effect . Estradiol had a greater effect on liver protein levels than did GH. When estradiol and GH were administered together to hypophysectomized animals there was no apparent additive effect of the …

The Effect Of Photoperiod On The Diurnal Fluctuations In Photosynthetic Rate Of Two Species Of Marine Phytoplankton, Richard Allmon Smith

Master's Theses

Photosynthetic rates were measured under constant conditions over a 24 hour period for cultures of Skeletonema costatum and Amphidinium carterae grown under various light - dark regimes. Photosynthetic rate fluctuated for both species under all photoperiods except for A. carterase under 8 hours light per day. Maximum photosynthetic rates occurred generally in the middle of the. light period and minimum rates.in the middle of the dark period. The ratio of maximum to minimum rates, or Pmax/min, differed significantly under the various photoperiods. Pmax/min values . for A. carterae were significantly greater than for s. costatum. The greatest Pmax/min for S …

A Comparison Of The Vibratory Muscle, Tail Epaxial Muscle, And Body Epaxial Muscle Respiratory Activities In Sistrurus Miliarius, Coluber Constrictor, And Natrix Fasciata, Craig Todd Kerins

Master's Theses

The rattlesnake can be distinguished from other types of snakes by its rattling apparatus. Klauber (1956) describes the rattle as an apparatus consisting of varying numbers of three lobed keratin segments. The segments arc arranged in a string by the loose interlocking of the segment lobes. The rattle is attached to tho. snake by the style, the modified terminal vertebra of the rattlesnake. The style is distally branched, forming a rigid core for the proximal rattle segments. A sound, unique to the rattlesnake, is produced when the segments arc vibrated at great frequencies by the snake's posterior tail musculature (Klauber, …

The Effect Of Estradiol On Protein And Nucleic Acids Of The Liver Of Natrix Fasciata, Alex Jordan

Master's Theses

The effects of estradiol on RNA, DNA, and protein concentrations in the liver of Natrix fasciata (southern banded water snake) were investigated. Nucleic acid and protein concentrations were determined spectrophotometrically and expressed as mg/gm wet weight tissue.

Significant increases in both RNA and protein occured 48 hours after a single injection of estradiol. After 72 hours the mean RNA level in estradiol treated snakes had decreased significantly from the 48 hour level. The mean protein level at 72 hours, although lower than the 48 hour level, did not decrease significantly.

Liver DNA concentrations in experimental and control snakes were the …

An Ultrastructural Investigation On The Origin Of Murine Langerhans Cells, Stanley Powell Tompkins

Master's Theses

The mammalian epidermis has been described as consisting of three different cell populations: keratinocytes, pigment cells, and Langerhans cells. Ultrastructural investigations of mamalian skin within the last decade have resulted in criteria whereby these cell types can be differentiated upon electron microscopic examination.

The present study was undertaken to investigate the occurrence of epidermal Langerhans cells in both neural crest-free and normal PET mouse skin, and to present evidence for a possible origin of the epidermal Langerhans cells of murine skin.

Refractoriness Of Pet Mouse Integument To The Nerve Growth Factor, Walter Hollified Dorman

Master's Theses

This paper deals with the refractoriness of PET mouse integument to the subcutaneous administration of nerve growth factor. Newborn mice were injected once daily with NGF through ten injections. Gross and histological examination showed that the skin of the experimental animals was completely unresponsive to this agent. No alterations in the hair growth cycle or pattern were observed.

The Effects Of Estradiol Benzoate On Protein Synthesis By The Isolated Perfused Snake Liver, William Ralph Boone

Master's Theses

The effect s of estradios benzoate on protein synthesis by the isolated perfused liver of Natrix fasciata fasciata (Linnaeus, 1766), the southern banded water snake, were investigated. The incorpora­tion of carbon-14 labeled leucine into plasma protein of the liver perfusate was used as an index of protein synthesis by the perfused liver.

Both control and experimental livers demonstrated incorporation of the labeled leucine into plasma protein. However, estrogen treated livers expressed significantly greater incorporation of the amino acid into plasma protein giving an almost linear response. Total plasma protein levels were also significantly higher in the perfusions involving estrogen treated …