No description available.

M.Sc. / Please refer to full text to view abstract

Thesis (M.Ph.)--Chinese University of Hongkong. / Bibliography: leaves 366-391.

Thesis (M.S.)--University of North Carolina at Wilmington, 2004. / Includes bibliographical references (leaves : [58]-64).

Thesis (M.S.)--University of New South Wales, 1999. / Title from PDF title page (viewed on May 2, 2005). Includes bibliographical references (p. [134]-154).

No description available.

A comparative, year long (15 month) study of three lakes (Whonock, Munday, Como) in the Lower Fraser Valley, British Columbia was undertaken to gain information on the physicochemical and seasonal limits of scale-bearing Synuraceae (Chrysophyta). In addition, sporadic collections were made in different lakes in this region to augment the information provided from the three main lakes. The synuracean taxa are reviewed with worldwide distribution lists, and environmental and seasonal information are discussed. Thirty-one taxa of Chrysophyceae were identified, of which 20 are in the Synuraceae. Eight taxa within this family are new records for British Columbia, viz. : Mallomonas cratis var. asmundiae Wujek et Van der Veer Mallomonas papillosa Harris et Bradley Mallomonas doignonii var. tenuicostis Asmund et Cronberg Mallomonas transsylvanica Peterfi et Momeu Mallomonopsis ouradion (Harris et Bradley) Harris Paraphysomonas vestita (Stokes) de Saedeleer Synura splendida Korshikov Synura glabra Korshikov It was found that the Synuraceae are not restricted to cold waters, as often assumed. Some taxa are present throughout the year. They do seem to favour acidic and sometimes dystrophic environments, and it is suggested that factors such as pH or water chemistry should be investigated as probable controlling factors for synuracean populations. Of the 11 non-synuracean Chrysophyceae noted', six are new records for the Province: Bicoeca kepneri, Chrysococcystis elegans, Dinobryon crenulatum, Epipyxis lauterbornii, Epipyxis utriculus var. acuta, and Eusphaerella turfosa. / Science, Faculty of / Botany, Department of / Graduate

published_or_final_version / Biological Sciences / Master / Master of Philosophy

On the basis of three morphological characters (e.g., filament, width, chloroplast number, and type of cell end wall), six filament types of Spirogyra were collected along Bear Creek in the Santa Catalina Mountains near Tucson, Arizona. The occurrence and distribution of filament types showed seasonal and geographical patterns. Filaments were more frequently collected in early summer from pools at lower elevation. Growth of Spirogyra may be influenced by water temperature, pH, and water amount. Most filaments occurred more abundantly while water temperture and pH were relatively high. The number of filament types was greatest at sites with a semi-permanent water supply rather than in temporary and permanent pools. Of the six types of Spirogyra, Type V showed morphological and genetic changes through vegetative growth and sexual reproduction in a clonal culture in the laboratory. After 33 months culturing, a narrower filament-width group (Group II, 22.0 ± 1.1 μm) was produced in the original clone (Group I, 30.9 (+OR-) 0.7 μm). Groups I and II were homothallic and sexually compatible. Zygospores from the cross of I x II yielded germlilngs of Groups I, II, III (27.2 ± 1.0 μm) and a binucleate IV (44.9 ± 0.8 μm). Chromosome counts were: Group I (24), Group II (12), Group III (18), and Group IV (24, one nucleus). Relative nuclear-DNA fluorescence values increased as filament width and chromosome number increased. Cytologically, Group I is a tetraploid, Group II a diploid, and Group III a triploid. Systematically, Groups I, II and III key out to pirogyra singularis, S. communis, and S. fragilis, respectively, using Transeau's monograph on Zygnemataceae. These species are interpreted to be a species complex of S. communis (whose name has priority) with the ancestral haploid (x = 6) missing. Five years after isolation of the original strain in this species complex filaments corresponding to Groups I and II were found at the original collection site. The two field-collected groups were indistinguishable from the laboratory species complex in morphology and chromosome number. Homothallic conjunction within two field width groups yielded progeny similar to those from homothallic conjunction of groups in the laboratory species complex. Filament widths of progeny were generally within the width limits of respective parental groups. The four intergroup crosses between laboratory and field width groups were successful and yielded progeny representing Groups I, II, and III. The similarities in morphology, chromosome numbers, and reproductive behavior of laboratory and field width groups imply that the laboratory species complex of S. communis has a natural counterpart in the field.

This project was designed to investigate the effects of carbon dioxide (CO2) levels on the growth and pigment ratios (chemotaxonomy) of freshwater algal species typical to the south Florida surface waters. Green algae, diatoms, and cyanobacteria were cultured under 400 or 800 ppm CO3 in air for several weeks. Growth monitoring used a cell counter, hemocytometer, and chlorophyll fluorescence. Pigments were analyzed using HPLC-PDA. Experiments with certified CO2 concentrations (400, 600, 800, 1200 ppm) were conducted with helium degassed ultrapure water and each of three culture media. Theoretical and experimental pH values with water matched exactly. However, each culture media proved to exhibit significant buffer capacity. Cell growth monitoring was problematic except for the cyanobacterium Microcystis aeruginosa. That species responded to increased CO2 (800 ppm) with increased growth rates as predicted. The other species gave erratic results mainly due to difficulties in obtaining valid consistent cell counts. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection