Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 266-270.).

Thesis (M.Sc. Biology)--University of Waikato, 2006. / Includes bibliographical references (leaves 90-101) Also available via the World Wide Web.

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AN ABSTRACT OF THE THESIS OF Elizabeth C. Geiger, for the Master's degree in Geology, presented on August 28, 2008, at Southern Illinois University Carbondale. TITLE: PALEOECOLOGY OF PLEISTOCENE GASTROPODS IN GLACIAL LAKE DEPOSITS IN SOUTHERN ILLINOIS/MISSOURI MAJOR PROFESSOR: Dr. Scott Ishman During the Pleistocene Epoch in the central Midwest United States multiple glaciations and interglaciations occurred in response to the advance and retreat of glaciers. This study focused on the Illinoian and Wisconsinan glaciations, which are separated by the Yarmouthian and Sangamonian interglacials. The advance of glaciers during glacial stages caused major rivers and their tributaries to aggrade creating slackwater lakes in many tributary valleys to the Mississippi River. Gastropod assemblages, found in glacial lake deposits, were used to interpret paleoecology during major glacial advances. Gastropods were collected from four sites in southern Illinois and Missouri to compare the Illinoian and Wisconsinan glaciations to one another, as well as to compare similar aged glacial lake deposits. This study identified forty-eight gastropod species, which were analyzed using statistical procedures. Hierarchical cluster analyses resulted in the identification of gastropod assemblages that were interpreted using habitat classifications. The results indicate specific similarities and differences between the Illinoian and Wisconsinan glaciations regarding environmental and climatic conditions.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16376号 / 工博第3457号 / 新制||工||1523(附属図書館) / 29007 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 細田 尚, 教授 後藤 仁志, 准教授 米山 望 / 学位規則第4条第1項該当

The intensive tank culture of ornamental mouthbrooding cichlids poses several problems which limit their aquaculture potential. This project addressed some of these problems for Aulonocara baenschi. The production of juveniles in 2501 aquaria was accelerated when: a) aquaria were equipped with refuges, b) females of less than 70mm in standard length were used as broodstock, c) mouthbrooding females were replaced with gravid females at seven day intervals, and d) embryos were removed from the mouths of females at replacement times for artificial incubation. Two sex ratios also accelerated juvenile production. The sex ratio (male:females) 1:30 yielded the highest spawning returns per tank, and therefore represented the most effective utilization of aquarium space (a critical consideration for the small-scale culturist). Contrastingly, the sex ratio 1:12 yielded the highest clutch sizes and a high percentage female spawning return, and therefore represented the most effective utilization of broodstock (an important consideration for culturists inhibited by financial constraints or having an abundance of culture vessels). The reproductive behaviour of A. baenschi was described. Emphasis was given to aspects of reproduction of relevance to culture, for example; spawning times and seasons, clutch size and its relationship with female size, age and size of sexes at first spawning, embryo development rate and size of first swimming juveniles. The slow growth rate of juveniles, combined with a late attainment of marketable size (± seven months) was a major limitation affecting the cuIture potential of A. baenschi. Two factors favouring the cuIture of this species was the high survival rate recorded for both adults and juveniles, and the comparatively high prices fetched by fish on domestic wholesale markets (R4,00 per fish). It is recommended that A. baenschi should not be cultured exclusively for the relatively small South African ornamental fish market. A more profitable strategy for domestic culturists should involve a major production effort with A. baenschi and other desirable species of Aulonocara (e.g . A. ethelwynnae; A. hansbaenschi; A. stuartgranti & A. maylandi) for foreign markets (in particular, the U.S.A.; Western Europe & Japan). Not only are these markets massive, but prevailing exchange rates of the Rand with these currencies favour such a strategy.

A field investigation was carried out over two seasonal periods on an oligotrophic coastal British Columbia lake to determine the role of sinking in the formation of the chlorophyll maximum as well as some aspects of phytoplankton seasonality. Sinking rates of two diatoms were measured and found to be highest in the epilimnion and lowest at the depth of the chlorophyll maximum. Light affected sinking rate as well as the position of the chlorophyll maximum. The chlorophyll maximum formed at 10-12 m following the onset of seasonal thermal stratification and descended to ca. 22 m for the summer. A major factor in the formation of the chlorophyll maximum is the decrease of phytoplankton sinking rate at depth. Rhizosolenia eriensis is one of the first phytoplankters to bloom in the spring. Small flagellates (3-15 um) and occasionally Dinobryon sp. were also important numerically. In the summer Cyclotella spp. displaced R. eriensis as the dominant diatom in the epilimnion. The relative timing of seasonal maxima of blooms of various species remained similar during the two years investigated. Lake fertilization affected the phytoplankton standing stock. R. eriensis did not greatly benefit from fertilization since it sank out of the epilimnion and became a major constituent of the chlorophyll maximum before fertilization. Because of its large size and low C : cell volume ratio due to a large vacuole, R. eriensis is probably not a good food source for zooplankton. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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