Biology Commons^™

The Effects Of Osmotic Stress On Sodium, Potassium, And Chloride Metabolism In The Mongolian Gerbil, Meriones Unguiculatus, Mark William Hagood

Master's Theses

The effects of osmotic stress on sodium, potassium, and chloride metabolism and the physiological mechanisms governing these ions were studied in the Mongolian gerbil, Meriones unguiculatus. Animals were subjected to dietary regimens ranging from sodium-free to high-sodium diets for sixty days. Results indicate the gerbils were not physiologically stressed by the imposed diets. Apparently the animals regulate ion metabolism via intrarenal mechanisms and pituitary antidiuretic hormone while behavior and adrenal cortical activity are insignificant.

The Spatial Distribution Of Phytoplankton In Westhampton Lake, Richmond, Virginia, James William Newlin

Master's Theses

The hypothesis is that spatial distributions of phytoplankton standing crop and photosynthetic capacity in Westhampton Lake are homogeneous was tested. Distributions were analyzed with respect to horizontal and vertical planes separately and combined. The study was divided into three time period: 1) late summer stratification, 2) early fall mixing, and 3) fall turnover, based on isothermal lines of the lake at the deepest station. Phytoplankton standing crop was measured by spectrophotometric and fluorometric methods. The photosynthetic capacity was measured flurometrically. Combined horizontal and vertical spatial distribution of standing crop was clumped for the entire lake and during each time period. …

The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of Pinealectomized Male Mice Mus Musculus, Icr Strain, John Earnest Constantine

Master's Theses

One hundred two male mice , Mus musculus, ICR strain, age four weeks, were obtained. Fifty-one mice were pinealectomized and 51 were sham operated. The animals were divided into three photoperiod groups: 1.5L:22.5D, 14L:10D, 24L; 0D. The mice were subcutaneously injected daily with 10 ug melatonin or control solution from post-operative day J to post-operative day 60, On post-operative day 60 representatives of each photo­ period-surgery-injection regimen were paired with females. The remaining animals were killed and several organs were removed and weighed, Melatonin injections were progonadal in pinealectomized mice and inhibitory in sham mice in several instances. Histological examination …

Population Stability Of Three Species Of Zooplankton In Westhampton Lake, Richmond, Virginia, James Christopher Conyers

Master's Theses

Populations of zooplankton, Keratella cochlea's (Rotifera) Bosmina longirostris (Cladocera), and Mesocyclopsedax (Copepoda) were sampled in Westhampton Lake from June 30 to December 22, 1978. Population densities were estimated over time and analyzed for stability relative to the occurrence of rainfall. Two aspects of stability were used for analysis and given operational definitions as follows: Resistance - a population was resistant if its density was not more variable during periods of rain compared with periods of little or no rain; Persistence - a population was persistent if its density during periods of rain was not different from its density in periods …

The Vascular Flora Of The Kersey-Crump Creek Watershed, Hanover County, Virginia, Eddie Reeves Smith

Master's Theses

A floristic survey was conducted in the Kersey-Crump Creek watershed, Hanover County, Virginia from spring 1978 through summer 1980. This upper Coastal Plain area (42 km2) near the fall line yielded 514 species of vascular plants, representing 334 genera and 113 families. Four hundred and seventy-nine county records were established. Panax trifolium, colonizing a rich wooded creek bottom, was the only plant rare to Virginia. Voucher specimens are deposited in the herbaria of the University of Richmond, Virginia, and the College of William and Mary, Williamsburg, Virginia.

Reproductive And Mutagenic Effects Of 5-Thio-D-Glucose Injections In Male Mice, Mus Musculus, Icr Strain, Mary E. Mcmanaway

Master's Theses

Adult male ICR mice of proven fertility were intraperitoneally injected daily with 60 mg/kg of 5-thio-D-glucose for 28 days. Body weights of treated male mice were unaffected during the experimental period. Relative testicular weights were significantly reduced at 121 days after initial injections in 5-thio treated males, but no significant decrease was observed at 28 days.

Onset of sterility was estimated to occur at approximately 4 weeks and persisted for 5 to 6 weeks after cessation of treatment at which time fertility was restored.

Beginning with the first injections and continuing for 121 days, the males were mated with untreated …

The Effects Of Photoperiod And Melatonin Injections On The Reproductive System Of Male Mice, Mus Musculus, Icr Strain, Margaret Ann Shugart

Master's Theses

The reproductive effects of long (24L:OD), natural (14L:lOD), and short (1L:23D) photoperiods were studied in the male mouse, Mus musculus, ICR strain. One third of the mice in each photoperiodic regimen were sacrificed after 45 days. Half of the remaining mice in each regimen received daily melatonin (5-methoxy-N-acetyl tryptamine) injections for 45 additional days. Body weights, testicular and accessory sex organ weights were measured and microscopic examinations of the testes were made. Plasma testosterone levels were determined using radioimmunoassay. Other organ (pituitary, kidney, adrenal, thymus, thyroid) weights were also obtained.

Seasonal Sexual Cycle Of Nerodia Taxispilota (Serpentes: Colubridae) At The Northeastern Edge Of Its Range, David Roland White

Master's Theses

The seasonality of the sexual cycle of Nerodia taxispilota at the northeastern edge of its range was elucidated from specimens collected over a two-year period (1978-1979) from the Appomattox River near Hopewell, Virginia. The investigation centered on morphological changes in the testis of males and vitellogenesis and embryo development in females. Related reproductive parameters also studied were body size differences, seasonal sex ratios, comparative tail lengths, and tail mutilation.

Male and female cycles closely resembled those of other temperate zone colubrids. Spermatogenesis began in May and testis size peaked in late August. Testis length showed a time lag when compared …

Growth And Food Habits Of Micropterus Salmoides In Westhampton Lake, Richmond, Virginia, Charles H. Rawls Jr.

Master's Theses

Age, growth, and food habits of the population of Micropterus salmoides (largemouth bass) in Westhampton Lake were studied from September to November 1978. Two year classes (0 and I) were identified by determining numbers of annuli on the scales of the fish. Growth data indicated that the bass attain a size of 254 mm (10 in.) near the end of their second summer. The length-weight relationship was log W = -4.6829 + 2.9153 log TL. The Fulton condition factor for the population was 1.40. Food habits were described by numerical and frequency of occurrence methods. Young of the year sunfish …

The Interacting Effects Of Tetraiodothyronine And Epinephrine On The Activities Of Na+ + K+ -Dependent Adenosine Triphosphatase, Hexokinase And Pyruvate Kinase In The Cardiac Tissue Of White Rats, Timothy Joseph Dietrick

Master's Theses

The interacting effects of tetraiodothyronine (T4) and epi- nephrine on Na++K+-dependent ATPase, hexokinase, and pyruvate kinase in cardiac tissue of white rats were investigated in an attempt to elucidate the hormonal regulation of heart metabolism. Previous evidence has shown that 90% of the increase in oxygen consumption exhibited by hyperthyroid rats was due to an activation of Na++K+- dependent ATPase. In addition, hypothyroidism in sheep was re­ ported to lower cardiac Na++K+-dependent ATPase activity as well as 8-adrenergic binding sites for epinephrine. As T4 and epinephrine enhance carbohydrate metabolism, hexokinase and pyruvate kinase, two essentially irreversible glycolytic enzymes, were also …

Growth And Food Habits Of Micropterus Salmoides In Westhampton Lake, Richmond, Virginia, Charles H. Rawls

Master's Theses

Age, growth, and food habits of the population of Micropterus salmoides (largemouth bass) in Westhampton Lake were studied from September to November, 1978. Two year classes (O and I) were identified by determining numbers of annuli on the scales of the fish. Growth data indicated that the bass attain a size of 254 mm (10 in.) near the end of their second summer. The length-weight relationship was log W = - 4.6829 + 2.9153 log TL. The Fulton condition factor for the population was 1.40. Food habits were described by numerical and frequency of occurrence methods. Young of the year …

The Role Of Na+ + K+ -Activated Adenosine Triphosphatase In The Osmoregulating Marsh Clam, Rangia Cuneata, David Goodwin Sainting

Master's Theses

The marsh clam, Rangia cuneata has been shown in other laboratories to maintain body fluid osmolality above that of the medium in salinities below 10 o/oo. Since the membrane bound enzyme Na ++ K+ - ATPase has been implicated in the osmoregulatory processes in many aquatic organisms, the levels of Na++K+-ATPase activity and 3H-ouabain binding in homogenized tissue samples from mantle, gill, rectum, ventricle, kidney, and foot (including epithelial and muscle tissue) were measured. Mantle, kidney, and gill contained substantial concentrations o f Na + +K+ -AT Pase acti. vi. ty an d 3H- ouab ai. n bin d"i ng …

The Effects Of Ph On Chloride Flux In Fundulus Heteroclitus, Timothy Alton Washburn

Master's Theses

The effects of increasing hydrogen ion concentration on rate of chloride influx and efflux were studied in the killifish, Fundulus heteroclitus, adapted to fresh water. Because increasing hydrogen ion concentrations have been shown to inhibit sodium influx and because evidence exists to support coupling of chloride transport with sodium transport, the present study was undertaken to determine what effect pH would have on rate of chloride flux. Chloride efflux rates were studied after the addition of sodium bicarbonate to the medium. No significant pH-dependent changes in efflux rate were observed, except at very low pH. Influx rates were significantly changed, …

An Ultrastructural Study Of Intramuscular Melanocytes In Pet/Wmr Mice, Charles August Gomer

Master's Theses

An examination of the lateral head of the gastrocnemius of the PET/Wn!.r mouse was made with an electron microscope. Cells of the perimysium and endomysium were described and the relationship of these cells to muscle cells was characterized. The relationship between melanocytes and muscle cells found in this strain was the major focus. Melanocytes were seen to be present in the perimysium and endomysium with the greatest concentration in the endomysium. Melanocytes of the perimysium appeared segregated from the adjacent tissue by fibroblasts,which surround ed the melanocytes with their cytoplasmic processes, a well as by collagen fibers. Melanocytes of the …

The Quality Of Storm Runoff From Different Kinds Of Land Surfaces In The Drainage Basin Of Westhampton Lake, Richmond, Virginia, Margaret Emil Coppedge

Master's Theses

Samples of runoff were collected during storms from four different areas within the drainage basin of Westhampton Lake, Richmond, Virginia, between October, 1977, and January, 1978. The areas were a residential area, concrete street gutter, asphalt parking lot, and broadleaf forest.

The samples were analyzed for pH, levels of reactive phosphate, nitrate, and turbidity, and their effects on the growth of algae from Westhampton Lake.

The pH of runoff from the residential area, gutter, and forest usually ranged between 6-7 and the parking lot usually ranged between 4-5. Levels of turbidity varied considerably between storms and areas. Runoff from the …

Lactate Dehydrogenase Isozyme Patterns From Five Species Of Snakes : Comparison Of Rattlesnake Vibratory Muscle With Body Epaxial Muscle, Cecil Bernard Cross

Master's Theses

Lactate dehydrogenase (LDH) isozyme patterns of seven tissues in each of five species of snakes are described from their polyacrylamide gel electrophoretic characteristics. The tissues examined included vibratory tail muscle, non­ vibratory tail muscle, body epaxial muscle, heart muscle, whole blood, liver and kidney. The species of snakes included Crotalus adamanteus, C. h. horridus, Agkistrodon piscivorus and Sistrurus miliarius barbouri from the family Crotalidae and Natrix taxispilota from the family Colubridae. These snakes show a decreasing continuum of tail vibratory activity, respectively, to N. taxispilota, which has a non­vibratory tail muscle.

Crotalus adamanteus, C. h. horridus and A. piscivorus have …

Distribution Of Etheostoma Nigrum Rafinesque, Etheostoma Olmstedi Storer, And Their Introgressive Hybrid Populations In The James River Drainage, John Edward Clark

Master's Theses

An analysis of proportional measurements and meristic characters of Etheostoma nigrum and E. olmstedi identified five populations within the James River drainage. Etheostoma nigrum inhabited the montane and piedmont areas through the Fall Line; E. o. atromaculatum was distributed throughout the tidal river and its lower tributaries; and E. o. olmstedi was restricted to creeks on the upper coastal plain. Appomattox River and Falling Creek contained introgressive hybrid populations with character frequency distributions intermediate to those of E. nigrum and E. o. olmstedi. It is proposed that E. nigrum probably entered these drainages through stream piracy on piedmont tributaries of …

Antipredative Function Of The Gelatinous Coating Of The Eggs Of The Frog, Rana Pipiens, Walter Stanley Jennings

Master's Theses

The eggs of Rana pipiens, the southern leopard frog, were offered in several forms to Lepomis macro­ chirus, the bluegill. The fish were offered random trial discrimination tests while in groups of one or five in 40 1 aquaria. L. macrochirus learned to make distinct discriminations and rejected fertilized and unfertilized egg masses, boiled egg masses, dried frog eggs and gelatin made with homogenated frog eggs. In contrast, Shrimp-el-etts, Shrimp-el-etts dyed black, gelatin made with peptone, and ovarian eggs were accept­ ed readily. The results suggest a protective function for the gelatinous coat: both physical and chemical . The chemical …

The Effects Of Prolonged Ultraviolet Irradiation On The Pigment System Of Pet/Wmr Mouse Epidermis, Penny Suzanne Nair

Master's Theses

Repeated exposure to ultraviolet radiation brings about an increase in the DOPA-positive melanocyte population of the human. However, there is an age-dependent decline in the melanocyte population regardless of UV irradiation. In the rhesus monkey, a drop in the DOPA-positive epidermal melanocyte population has been observed after prolonged UV irradiation. The population of DOPApositive epidermal melanocytes in PET/Wmr mice reaches a peak during the first post-natal week after which the number of cells declines, fading almost completely within 3 weeks. Their occurrence in adult mice is rare. With UV irradiation (300 nm) the melanocyte population of newborn and adult PET …

The Effect Of Photoperiod On The Regressive Phase Of The Ovarian Cycle Of The Lizard, Anolis Carolinensis., John Dickens Pinch

Master's Theses

The effects of constant photoperiod (14 hours of light) and decreasing photoperiod (13-8 hours of light) on the regressive phase of the ovarian cycle of the lizard Anolis carolinensis were investigated. Changes in body, liver, ovary and oviduct weights were measured and microscopic examinations of several ovarian parameters were made. In both light regimens body and liver weights decreased over the first four weeks of the experiment but both increased at the sixth week. In addition, ovary weight was highly variable but exhibited a decreasing trend and oviduct weight decreased. There were decreases in the number of previtellogonic follicles and …

Seasonal Nearshore Distributions Of Fishes In A Piedmont Section Of The James River, Virginia, Eugene George Maurakis

Master's Theses

The seasonal nearshore distributions of 17 species of fishes were determined in natural and artificially heated areas in a 9.6 km stretch of the Piedmont section of the James River, Virginia from July, 1973 to June, 1974. Analyses of the seasonal distributions were based on abundance and percent frequency of occurrence data. The maximum abundance and percent occurrence of ten of the 17 species of fishes in natural temperature areas occurred in early autumn. Deviations from this pattern included Notropis analostanus, equally abundant throughout the year, and Lepisosteus osseus, Notropis amoenus, Notropis ardens, Notropis rubellus, Catostomus commersoni and Lepomis macrochirus, …

The Modification By Temperature Of The Effects Of Mammalian Follicle Stimulating Hormone And 17b-Estradiol On The Process Of Vitellogenesis In The Lizard, Anolis Carolinensis, Susan Howard Early

Master's Theses

The effects of porcine follicle stimulating hormone, 17B-estradiol, and a combination of the two on the process of vitellogenesis were studied in Anolis carolinensis maintained at 15C with no light for one week, and then at 15C or 32C with 14 hours of light for two additional weeks.

At both temperatures, the control animals subjected to 14 hours of light possessed greater numbers of previtel­logenic follicles and lower liver weights than the control animals sacrificed after one week in the dark. Animals maintained at the higher temperature and given different hormonal treatments showed significant increases in ovary and oviduct weights, …

The Relationship Between Gill Na+ + K+ -Activated Adenosine Triphosphatase Activity And Sodium Regulation In Acclimation Of The Blue Crab, John Lewis Harris

Master's Theses

Evidence from this study suggests that Na++K+-activated ATPase is involved in the ionic regulation of sodium in the hemo-lymph of the blue crab in low salinity environments. The time course of changes in gill Na++K+-ATPase specific activity follow- ing transfer of crabs from JO o/oo to 5 o/oo salinity indicates that a major increase in activity occurred within 2.5-3.0 hr. Apparently, a 8.8-11.1% decrease in hemolymph sodium ion concen-tration to about J55-J60 meq/1 in approximately 2-J hr was sufficient to activate the ATPase cation transport system in the gills of Callinectes sapidus. Following enzymatic activation, hemolymph sodium concentration gradually approached …

The Role Of An Eyestalk Extract In The Regulation Of The Blood Sodium And Calcium Concentrations Of The Blue Crab Callinectes Sapidus, Gregory Martin Ivy

Master's Theses

The effect of bilateral eyestalk ligation or ablation on the blood Na+ and ca++ concentrations of the euryhaline blue crab, Callinectes sapidus, was measured in 10 o/oo and 5 o/oo sea water. The ablations caused a significant decrease in the blood Na+ and ca++ over a 24 hour period. The serum Na+ level increased significantly 6 hours following injections of an eyestalk extract whereas the blood total ca++ level did not change significantly. Eyestalk ligation, however, did not cause significant blood Na+ and ca++ changes. The blood Na+ level of intact crabs increased significantly in acclimating to colder water when …

Populations Of Lepomis Auritus (Redbreast Sunfish) In A Thermally Influenced Section Of The James River, Virginia, John Rawls Saecker

Master's Theses

From October 1971 - September 1973, electrofishing was used to collect 1004 specimens of Lepomis auritus (year classes 0 - V) from a thermally influenced section of the James River near Blemo Bluff, Virginia. Collections of fish from the natural and heated water temperature habitats were analyzed as to year classes, season, length and sex.

The Effects Of Topical Nitrogen Mustard On The Pigment System In Pet/Wmr Mouse Epidermis, Ronald Lee Salisbury

Master's Theses

Miniature melanocytes have been observed scattered among the typical melanocytes in the skin of the PET/Wmr mouse strain, They are weakly DOPA reactive and their cell bodies and nuclei are one quarter the size of those in typical melanocytes, Both populations reach a peak during the first postnatal week and then gradually disappear within the following three weeks. The miniatures appear very early and are among the last cells to disappear. During the first postnatal week, their population remains relatively constant against a radically changing population of typical melanocytes. That they may represent a stage in the development of typical …

Melanin In The Longnose Gar, Lepisosteus Osseus, George William Minson

Master's Theses

Examination was made of the melanophores of three Lepisosteus osseus (longnose gar), one dark, one intermediate, and one normal in pigmentation. Melanophore counts were made per mm² from anterior, mid, and posterior areas of both the dorsal and ventral surfaces of each of the three fish. The data were tested with a four-factor analysis of variance. By microscopic examination the melanophores were classified as to branching in the sample areas. Neither number of melanophores nor degree of branching explained divergence in pigmentation. However, divergence was attributed to the melanosome color and concentration in the melanophores.

Effects Of The Toxins Of The Ectoproct, Lophopodella Carteri, On Oxygen Consumption In Gill Tissues Of The Bluegill, Lepomis Macrochirus, Barbara Harper Green

Master's Theses

Large and small bluegill, Lepomis macrochirus, were exposed to homogena tes of Lophopodella carteri, an ectoproct that contains substances toxic to some gilled vertebrates. Oxygen consumption tests on the excised gill tissues of the bluegill indicated that the ectoproct toxins caused a lowering of oxygen consumption of the gill tissues. Oxygen consumption of the gill tissues of the smaller fish was reduced to a greater extent than that of larger fish. An inverse relationship was found be tween the temperature of the medium and the period of time for death to occur. It is proposed that the toxins cause physiological …

Actions Of Mammalian Gonadotrophins In Female Anolis Carolinensis (Green Anole) Within Selected Parameters Of Photoperiod And Temperature, Frank Loving Holt Jr.

Master's Theses

The effects of either porcine FSHt equine LH, or both combined upon the pregametic a.nd gametic phases of the ovarian cycle of Anolis carolinensis {green anole)were investigated in animals maintained under one of three photothermal. regimens: 3 hours light at 15 C; 14 hours light at 15 C; or 14 hours light at 32 C.

Increases in pre-vitellogenic follicle diaaeter and ovarian weight were significantly greater at 32 C than at 15 c. A trend towards decreased numbers of atretic follicles with increased gonadotrophin dosage occurred in response to 14 hours light at 32 C. Gonadotrophin dosages which stimulated vitello­ …

Effects Of The Toxins Of Lophopodella Carteri (Ectoprocta), On Blood Lactate And Electrolytes Of Lepomis Macrochirus (Bluegill), Robert Fisher Dance

Master's Theses

Specimens of bluegill (Lepomis macrochirus) were exposed to homogenates of Lophopodella carter, an ectoproct that contains substances toxic to some gilled vertebrates. The homogenates caused significant decreases in blood Na+ and Cl - and a significant increase in lactate. Potassium levels were unaffected. It is proposed that these changes in blood. properties were caused by damage to ion transport mechanisms of the gill epithelium.