Biology Commons^™

Colonial Independence Of Feeding Among Zooids Of The Ectoproct Lophodella Carteri (Hyatt), Leonard M. Bahr

Master's Theses

Possible interactions of feeding between zooids of colonies of the freshwater ectoproct Lophopodella carter! were investigated. Suspensions of Euglena gracilis at a concentration of 558x10³ cells ml^-1 were cleared by L. carter at a rate of 2.7 x 10^-3 ml min^-1 zooid^-1 for15 minute periods. The rate of ingestion of E. gracilis by L. carter was independent of the size of colony and decreased exponentially with time, declining to about one third the original rate in 60 minutes.

The Effects Of Coelomic Fluid And Isotonic Homogenates Of The Freshwater Bryozoan Lophopodella Carteri On Fish Tissue, Roger H. Meacham

Master's Theses

A study was made to determine if fish tissue was poisoned by the coelomic fluid extracted from the common coelomic cavity of colonies of the freshwater bryozoan, Lophopodella carteri (Hyatt). Additional studies were made of fish tissues, in vivo and in vitro, when exposed to homogenates of crushed colonies of L. carteri in isotonic medium.

The fish exposed to the coelomic fluid did not show any signs of respiratory distress and therefore the poisonous quality must be located elsewhere in the bryozoan. The homogenates were determined to be poisonous as fishes exposed to a 3.0% solution were killed within an …

A Comparative Study Of The Sulfhydryl Groups In The Gastrocnemius Of The Normal And X-Irradiated Pet Mouse, Robert Edward Shervette

Master's Theses

It has been recognized that hyperpigmentation of the skin is the result of eliminating the. -SH inhibition when treatment is by x-irraidiation. The results of a. study by fieams and Schaeffer indicate : a progressive increase of melanocytes in the skin with an increasing dosage of x-irradiation. However, it was also noted that the effect of x-irradiatin on the gastrocnemius of the PET mouse resulted in a decrease in the number of intramuscular melanocytes. The present study was designed to determine whether the changes in the x-irradiated muscle is related to possible changes in -SH concentration.The technique employed is a …

The Ultrastructure Of The Vibratory Muscle Of Crotalus Horridus, Louis Pastore

Master's Theses

A comparison of the vibratory and epaxial muscles of Crotalus horridus horridus Linnaeus wa smade. muscle fibers, fibrils, filaments, mitochondria and sarcoplasmic reticulum were described in this study. The sarcomeres of the epaxial muscle were almost three times the length of those of the vibratory muscle. The A band was observed to be about twice the length of the I band in the vibratory muscle. As seen in cross section the vibratory muscle had fibrils arranged in discrete packets with a limited number of thick myofilaments. In contrast, the fibrils of epaxial muscle were less conspicuously separated from each other …

The Comparative Osteology Of The Trunk Skeletons Of Three Species Of Paralichthys, Family Bothidae, From North Carolina, William Marion Hall

Master's Theses

Paralichthys albigutta Jordan and Gilbert, the gulf flounder, which occurs over sand bottoms, and Paralichthys let:nostigma Jordan and Gilbert, the southern flounder,which occurs over mud bottoms , are southern species with ranges extending into the Gulf of Mexico.Paralichthys dentatus, the summer flounder, is tho northern species and is tolerant of several types of bottoms but is most frequently found over sand or hard bottoms. The ranges of the three species overlap in an area along the eastern coast of the United States from central North Carolina to near Jacksonville, Florida. The flounders are closely related and unless the pig­ment pattern …

A Study Of Hybridization And Behavioral Characters In Percina Notogramma (Rany And Hubbs) And Percina Peltata (Stauffer), Family Percidae, Jules J. Loos

Master's Theses

In view of the close phylogenetic relationship between the two sym­patric species of darters, Percina notogramma (Raney and Hubbs) and Percina peltata (Stauffer), placed in the subgenus Alvordius by Bailey and Gosline (1955), it is of interest to compare them in more detail than has been done in the past. Percina notograrnma occurs only in the Chesapeake Drainage in Virginia, Maryland and West Virginia whereas P. peltata ranges from Virginia to New York. Adequate comparisons of their external. morphological characters have been presented by Raney and Hubbs (1948) in their original description of P. notogramma. Supplementary data were provided by …

Electrical Response Of Frog Skin Epidermis To Sodium Ions, James H. Martin

Master's Theses

Presently, the theory is held that the total frog skin potential (P.D.) is generated within the epidermis at two borders, the "outer border" and the "inner border, " which are said to be specifically permeable to Na⁺ and K⁺, respec­tively. This thesis concerns itself only with the electrical response of the "outer border" to varying Na⁺ concentrations in the solutions at the epidermis, [Na⁺]_o. Contrary to expectation from the Nernst equation, the P.D. changes by only 17 to 35 mV, instead of theoretically 58 mV upon a 10 fold change in [Na …

Respiratory Activity Of Vibratory, Tail Epaxial And Midbody Expaxial Muscle In Crotalus Horridus, Aqkistrodon Contortrix, And Thamophis Sirtalis., James E. Forbes

Master's Theses

The purpose of this study was to determine if the muscles associated with tail vibration in snakes are physiologically specialized for vibration. Timber rattle­ snakes (Crotalus horridus) , copperheads (Agkistrodon contortrix) and garter snakes (Thamnophis sirtalis) were used. The copperhead represented a species which vibrates its tail but has no vibratory apparatus comparable to that of the rattlesnake. The garter snake does not vibrate its tail. A comparison of respiratory activities was made between the vibratory and tail epaxial muscle and the mid­ body epaxial muscle within and between the three species. Oxygen consumption of teased muscle fibers and muscle …

The Effects Of A Nerve Growth-Promoting Protein On The Integument Of Pet Mice, Craig Bauman Satterlee

Master's Theses

A factor which specifically stimulates the growth of sensory and sympathetic nerve cells has been under investigation for a number of years. This factor, originally isolated in 1951, from mouse sarcomas 37 and 180, was named the "nerve growth factor". Its action was first shown in vivo by inoculating the sarcoma into chick embryos and subsequently in vitro by culturing chick ganglia and mouse sarcoma together. In the years immediately following the initial discovery, much more potent sources of NGF were found in the salivary glands and salivary secretions of a variety of species. These include rattle snake venom, and …

A Comparative Study Of The Parasite Of Certain Salientia From Pocahontas State Park, Virginia, Ronald Arthur Campbell

Master's Theses

Four species of salientia representing three selected habitats were collected from May 5th through October 4th, 1966 and examined for parasites. Of the 116 host specimens, 30 were Rana catesbeiana Shaw; 29 clamitans Latreille; 29 Bufo fowleri Hinckley; 28 Hyla versi­color (Le Conte). A total of 34 species of parasites was recovered: Protozoa, 10; Trematoda, 9 ; Cestoda, 2; Nematoda, 11; Acanthocephala, 1; and Acarina, 1.

Although a relatively small number of hosts was examined , the results generally agree with those found in more extensive investigations of similar type. The aquatic hosts, R. catesbeiana and R. clamitans, harbored the …

A Metabolic Study Of The Isolated Perfused Snake Liver, James E. Turner

Master's Theses

A metabolic study was made on the isolated, perfused liver of Natrix fasciata fasciata (Linnaeus, 1776). Uric acid production, perfusate protein levels, serum protein patterns, perfusate glucose levels, and bile production were evaluated in this study as criteria of liver function.

The perfused liver was found to produce uric acid up through the fourth hour of perfusion. No significant differences (between the perfusions) were found in uric acid production/ gm of liver tissue.

Perfusate protein and glucose levels were found to be of a fluctuating or cyclic nature. There was found to be an inverse relationship between these two levels: …

Interference Of Ultraviolet Inactivated Parainfluenza 3 And Echo 21 Viruses With The Active Viruses In Tissue Culture, William Ernest Steinmetz

Master's Theses

Experiments were conducted to investigate the possibility of the production of interference by ultraviolet inactivated (UVI) Parainfluenza 3 (Para 3) and Echo 21 viruses with active Para 3 and Echo 21 viruses in tissue culture (TC).

Four major experiments were conducted: the effect of UVI Para ~ on active Para 3 in rhesus monkey kidney cell (MKC) tissue culture; the effect of UVI Para 3 on active Para 3 in HEp-2 TC; the effect of UVI Para 3 on Echo 21 in MKC TC; and the effect of UV! Echo 21 on Echo 21 in MKC TC. The rates of …

The Comparative Osteology Of The Skulls Of Three Species Of Paralichthys, Family Bothidae, Anne Caperton Beirne

Master's Theses

This study was undertaken to determine if there were osteological variations in the skulls of young summer flounders, Paralichthys dentatus (Linaeus), southern flounders, Paralichthys lethostigma Jordan and Gilbert and - gulf flounders, Paralichthys albigutta Jordan and Gilbert that could be used as bases of species separation. As two of the species (dentatus and lethostigma) are of considerable economic importance, it would be of substantial value to establish skeletal characters that would help identify the young and. subsequently aid in determining their particular habitats where they occur in the same area.The three are closely related and difficult to recognize unless the …

Some Morphological And Histological Effects Of The Poison Of Lophopodella Carteri (Hyatt) On Young Ambystoma Opacum (Gravenhorst) And Carassius Auratus (Linnaeus), Eric Justin Collins

Master's Theses

Larvae of the marbled salamander, Ambystoma onscum, and the goldfish, Carassius auratus, were subjected to poi­ soning by homogenates of Lonhopodella carteri. Stock homogenates were prepared by grinding specimens of frozen L. carteri in a rotary blender and adding distilled water to give a 20 percent concentration (wt./vol.); the stock was used to prepare working solutions.

Homogenates from bryozoans collected in 1964 were approximately twice as poisonous as those from the 1963 col­ lection. It ls possible that chemical changes during stor­ age and bacterial action prior to freezing caused deterioration of the poisonous principle in the material from 1963. …

Percina Notogramma Montuosa Hogarth, A New Subspecies Of A Percid Fish From The Upper James River, William Thomas Hogarth

Master's Theses

Percina notogramma montuosa is described from 50 specimens taken in the tributaries of the upper James River. It is best separated from Percina notogramma notogramma, which inhabits the lower James, Rappahannock, York, Potomac and Patuxent rivers, on the basis of lateral-line scales (average difference 89%) and scales around the caudal peduncle (average difference 79%). A comparison of the meristic indices resulted in an average difference of 89%. A total of 18 out of 31 meristic and proportional characters were found to give significant differences.

The relatively few specimens from the Rappahannock, Potomac and Patuxent rivers precluded an intensive investigation of …

Some Factors Involved In Growth And Sporulation Of Pilobolus Crystallinus Tode And Pilobolus Umbonatus Buller, Kenneth L. Poff

Master's Theses

Pilobolus umbonatus Buller and P. crystallinus Tode grew normally in a nitrogen atmosphere but their sporagnia were non-pigmented. When palced in anaerobic jars along with obligately anaerobic and obligately aerobic bacteria, the fungi grew in the range of oxygen concentrations too low for growth of the aerobic bacterium, but high enough to prevent growth of the anaerobe. The fungi did not grow when the oxygen was depleted to the point that allowed growth of the anaerobic bacterium. Catalase was not produced by the hyphae and trophocysts which normally grow beneath the surface of the medium, but was present in the …

Photoperiodism And Other Factors Affecting The Germination Of Statoblasts Of Lophopodella Carteri (Hyatt), Elizabeth Ann Bergin

Master's Theses

Sample groups of the statoblasts of Lophopodella carteri (Hyatt) were pretreated by drying, cooling, freezing, immersion in water and combinations of these conditions. Then, they were subjected to 24-hour dark and 8, 12, and 24 hour light photoperiods . A control was maintained under natural dark-light (day-night) conditions. The analysis of variance and Newman-Keuls tests were used to analyze the data. The cool wet pretreatment gave the best germination for the statoblasts. For the photoperiods, statoblasts in 8 and 12 hour light periods and the control had the highest germination rate.

When sodium hypochlorite was used to surface-sterilize the stato­ …

Histological And Cytological Changes In The Small Intestine Of Hyla Versicolor Le Conte During Metamorphosis, Henry B. Robinson

Master's Theses

The object or the present study was to determine the histological and cytological changes that occur, during metamorphosis, in the small intestine of versicolor Le Conte. It was felt that such a study would clarify and amplify earlier observations.

A Histomorphological Comparison Of The Urinary Systems In The Serranid Fishes, Roccus Sexatilis (Walbaum) And Roccus Americanus (Gmelin), Irwin Beitch

Master's Theses

The urinary systems of Roccus saxatilis (Walbaum) and Roccus Americanus (Gmelin) were studied to check the validity of the monogeneric classification and to examine the osmoregulatory mechanism that allows the species to survive in environments of various salinities. The gross anatomy of the urinary systems of 13 R saxatilis and 12 R. americanus showed a number of similarities to exist, e.g. the general mesonephric form and size, uretal position and length, and the renal venous system. The head kidney, a hemopoietic organ, was larger in R. ­saxatilis than in R. americanus. Histological comparisons were made of H and E serial …

Some Effects Of Ph, Temperature And Light On The Production Of Zoosporagia In Saprolegnia Parasitica Coker, Philip C. Lee

Master's Theses

Pure cultures of Saprolegnia parasitica Coker were grown under varied conditions of temperature, pH, and light conditions. In liquid medium colonies were spherical with a zonal effect in the distribution of zoosporangia.

Near the limiting extremes of pH and temperature, beaded hyphal tips were found in place of normal sporangia. Teorell Universal buffer in the sporulation water inhibited production of sporangia. The pH minimum was 4.0 - 4.1, optimum 6.3 - 7.4, and maximum 8.o - 8.3. The maximum number of sporangia was produced at 15 C. Between 3.4 and 5 C , a delay in sporulation was noted and …

A Survey Of Parasitism In A Population Of Pigeons, Robert Flynn Jochen

Master's Theses

Numerous papers relative to parasites in pigeons can be found in the literature, but information concerning parasitic infections in pigeons of Virginia is scant, and no survey of parasitism has been made. Furthermore, no one survey or parasitism in pigeons of North America has included the incidence of both ectoparasites and endoparasites. Information relative to the incidence of individual parasites or groups of parasites, however, is available in recent literature, as well as information concerning isolated cases of parasitism

The present study was undertaken to (1) determine the nature and extent of parasitism in a population of pigeons in Henrico …

Determinants Of Occurrence And Distribution Of Fungi In Marine Environments, Paul W. Kirk

Master's Theses

Studies ware made of the effects of temperature and nutrient levels on salinity optima for growth and sporulation of Chaotomium Globosum and two marine Pyranomycetes, Torpedospora radiata, and Halosphaeriopais sp. Methods of culture and evaluation of sporulation were also investigated.

Discussion focused on ecological implications of data, in particular, on the probable survival value to a marine-fit fungus or a Phoma pattern mechanism-envolving vegetative and reproductive phases. As the seasons progress, the region where concentrations and proportions or salts are most favorable remains similar to that where vitamin requirements are least and biotic factors are most favorable.

Blood Oxygen Capacity Of Birds, J. R. Powell

Master's Theses

Avian blood oxygen capacity (BOC: Vol. %) was measured by a modified Roughton - Scholander syringe method with regard to parameters of body weight and sex. Two samples, collected from the Richmond vicinity, were investigated: the domestic pigeon (Columba livia Gmelin) and 25 other bird species.

A Study Of The Roots On Stem Cuttings Of Pedilanthus Tithymaloides Smallii (Millsp.) Dressler, Leonard Morrow

Master's Theses

The geographical distribution of Pedilanthus tithymaloides is variously listed as Tropical America (Engler, 1919); from Florida to Venezuela (Taylor, 1936); and Caribbean America (Dressler, 1957). Because of its use as an ornamental, the plant is also found in Mexico, China and Java (Dressler, 1957); Hawaii (Degener. 1940); and Bermuda (Britton, 1918). Banerji (1951) and Rao (1956) have worked with fresh hedge material from India. White et al (1941) report that the species is found growing on the graves of natives in Zululand and Rhodesis, and acknowledge that the introduction "from American into the native kraals is a mystery."

The present …

A Survey Of The Food Habits And Distribution Of The Fishes Of Tuckahoe Creek, Virginia, With Special Emphasis On Lepomis Macrochirus Rafinesque, David Andrew Flemer

Master's Theses

An integral part of the ecological study of any organism is a good understanding of the food relationships. Basic studies of the distribution and ecology of common fresh-water fishes are necessary before a more detailed analysis can be made of the fishes in a particular area. Lagler (1956) states that food habit studies help determine population levels, rates of growth, and condition of the fishes. He also concludes that they serve as a partial basis for determining the status of various predatory and competing forms. Raney (1942) states that an intelligent fishery management program depends heavily upon information gained through …

Observations On The Biology Of Pelomyxa Palustris Greeff, Collected Under Polysaprobic Conditions, Daniel Henry Stern

Master's Theses

Pelomyxa palustris Greeff, the largest rhizopod of which we have knowledge, was described in 1870 by Greeff who named the organism Pelobius. According to Penard (1902) it was redescribed by Archer in 1871 and reviewed. by Greeff (1874) who then gave it the name P. palustris.

A Comparison Of The Blood Oxygen Capacity In Semi-Terrestrial And Aquatic Frogs, Francis Burke Leftwich

Master's Theses

The present investigation is a comparison of the blood oxygen capacity in three species of frogs: a semi-terrestrial form R. pippins, the meadow frog; and two aquatic forms, R. clamitans, the green frog; and R. catesbeiana, the bullfrog. The habitats or these frogs are described by Wright and Wright (1949) as follows: R. pipiens inhabits swampy marsh lands, upland backwaters, overflows, and ponds in the spring. In summer it is found in swamp lands, grassy woodlands, or in cultivated hay and grain fields. In winter it hibernates in pools or marshes. It has been found as far as …

A Comparison Of The Blood Oxygen Capacity In Painted Turtles (Chrysemys Picta Schneider) And Box Turtles (Terrapene Carolina Linne), Harold J. Payne

Master's Theses

Among factors necessary for an animal to maintain life is the presence of an oxygen carrier that will transport a sufficient quantity of oxygen necessary for respiratory metabolism. In animals whose blood contains hemoglobin, which is a pigment that loads and unloads oxygen, this carrying capacity is referred to as blood oxygen capacity. It is a measure of the amount of oxygen that will combine with whole blood when completely mixed with air. It is usually expressed in volumes per cent (ml. 02/100 ml. blood) and corrected to standard temperature and pressure.

A search of available literature revealed that there …

A Critical Study Of The Chromosomes In Two Species Of Myxophyceae, John Thomas Mullins

Master's Theses

The Myxophyoeae or blue-green algae have been frequent subjects for cytological investigation since Schmitz (1879) first called attention to two regions in the protoplast. Since that publication the morphological and chemical nature of the genetic material and the mechanism of cell division in the Myxophyceae has been a controversial subject, The evidence that has been presented is, tor the most part, more voluminous than enlightening.

This investigation was undertaken in order to verify the methods and check the results obtained with the smear technique by Strickland (1948). Additional methods were also applied which might enable a more critical evaluation of …

The Comparative Morphology Of The Central Nervous System Of The Larva, Pupa, And Adult Of Epilachnia Corrupta, Raymond F. Moore

Master's Theses

The nervous system of insects has been subject of much study and research. By far the greatest part of this work has been on the orders of Orthopters, Lepidopters, Hymenopters, Diptera, and Coleoptera. This has been limited, in most cases, to a particular stage in the life history of the insect. This paper looks to study the morphology of the central nervous system of Epilachnia corrupta through all its stages in its life cycle.