Thesis (Ph. D.)--Wildlife and Fisheries Sciences Dept., South Dakota State University, 2009. / Includes bibliographical references. Also available via the World Wide Web.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1961. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 144-149).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 59-63).

This thesis explores the feeding habits of sunfish and bluegill in Texas lakes. Data gathered for this study is aimed to aid conservation of these pan fish by making a contribution toward a greater life history understanding of each species.

The ninety-six hour TLm value for molybdenum as sodium molybdate to bluegills was determined as 1320 ppm molybdenum in ion-free water. / Master of Science

A video-computer monitoring system was developed for use evaluating the effects of environmental factors and toxicants on fish behavior. The system recorded the X and Y coordinates of individual fish at 4-second intervals in a 50 cm square observation area and subsequently calculated 13 different behavioral parameters from the resulting time series of coordinates. The standard (control) swimming behavior of bluegills, Lepomis macrochirus, Raf., in the system was characterized in terms of activity, turning and spatial selection parameters over periods of 3 to 4 days and at two temperatures, 5 and 22 °C. Activity started at high levels on Day 1 and gradually decreased with time. The rate of this decrease was greater at 5 °C than at 22 °C. Turning behavior did not change in scale with time but did become more variable after an initial exploratory period. Spatial selection trends included a tendency for bluegills to spend more time around the periphery of the observation area than in the central area, and a tendency to spend more time in the downstream end of the observation area than in the upstream end. The behavioral responses of bluegills to abrupt, sub lethal (1 and 10% of the 96-hr LC50) gradients of ammonium chloride at 22 °C were assessed using the same system. The lower concentration gradients produced temporary increased activity and increased use of near-gradient areas. These responses were considered to be related to exploratory behavior. The higher gradients produced avoidance by 3 out of 4 fish; but these results conflicted with those obtained from previous tests conducted at 14 °C. Because of this discrepancy it was hypothesized that low temperatures interfere with the ability of bluegills to either detect ammonia after a certain period of exposure or their ability to behaviorally compensate for physiological stress produced by ammonia- gradients of this strength. / Ph. D.

Normal ranges of values for hematological parameters of bluegill gathered seasonally from three lakes were determined. Sexual, seasonal, and inter-lake variations were found. Effects of 2-wk exposure to turbidity on blood parameters included an increase in rbc size and a decrease in small lymphocytes. Effects of 3-hr exposure were increases in rbc count, hemoglobin, and pH and decreases in PG2 and large lymphocytes. The effects of 0.44 and 0.88 ppm chloramines were an increase in blood pH, a decrease in MEV, and severe spastic reactions resulting in loss of equilibrium or death in 90% of the fish. Effects of Flexibacter columnaris included an increase in transformed lymphocytes and a decrease in small lymphocytes.

The effects of sublethal copper on metabolism were in vestigated in bluegill (Lepomis macrochirus) by measuring whole body oxygen consumption in fish exposed to sublethal copper alone and in conjunction with a temperature increase. In vitro oxygen consumptions of liver, brain, and gill were also measured under these two conditions, as was the accumulation of copper in these tissues. In addition, the concentration of copper in bile was measured. Copper was found to decrease whole body oxygen consumption in animals exposed to copper alone, although the oxygen consumptions of tissues were not significantly altered. This indicates that copper is acting to decrease VO₂ at a higher level of integration than the individual tissues. In animals subjected to an increase in temperature as well as sublethal copper, oxygen consumption was higher than controls five days after the temperature was increased, indicating a delay in temperature acclimation. This increase was reflected in higher in vitro oxygen consumption in the liver and gill indicating that sublethal copper delays temperature acclimation by acting directly on the tissues. Tissue copper accumulation was seen first in the gills followed by accumulation in the liver. Copper was not found to accumulate in the brain. Increased copper levels were found in the bile at all tested exposure times. A discussion of the ecological implications of these findings is included. / M. S.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains vii, 88 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

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