Two species of fish, Carassius auratus and Ictalurus nebulosus, were subjected to cold acclimation regimes. Acclimation temperatures were slowly lowered to 3°c, then held for a period of time. At various times during this regime, fish were taken out and allowed to spend time in a temperature gradient to determine their preferred temperatures. Carassius were left in the gradient just long enough to determine a measure of the acute temperature preference, while Ictalurus were left in the temperature gradient for longer periods of time to observe any changes that might occur as the fish adjusted to selected temperatures. In both species of fish, lower acclimation temperatures and increased time spent at low temperatures caused a preference for lower temperatures in the gradient.

Long-Evans rats were raised from birth to eight weeks of age at 5°C, 20°C and 30°C. Blood was taken from animals two to eight weeks of age and assayed for growth hormone and thyroid stimulating hormone. The 30°C reared rats were found to have the longest ear, tail and hind limbs, followed by the 20°C reared rats. The 5°C rats were found to have the shortest ear, tail and hind limb. The 30°C and 5°C reared rats were found to have similar masses at the termination of the experiment. The 20°C reared rats had the smallest mass. Differences in size between the three groups when compared on a weekly basis were not found to be related to weekly obtained serum levels of growth hormone and thyroid stimulating hormone. Food consumption was greatest for the 5°C reared rats followed by the 20°C reared rats. The 5°C reared rats were found to have the lowest routine metabolic rate in the 5°C chamber. The 20°C reared rats were found to have the lowest routine metabolic rate in both the 20°c and 30°C chamber. When 30°C and 20°C reared rats were put in the 5°C chamber with the 5°C reared rats, they initially lost mass, however after three weeks in the 5°C chamber they began to gain mass. The 30°C reared rats gained mass at a greater rate than did the 20°C reared rats. The 5°C reared rats continued to gain mass throughout this period. While in the 5°C chamber the total food consumption of the 20°c reared rats was the greatest, whereas the 5°C and 30°C reared rats consumed similar amounts of food.

It is the purpose of this research to study the effect of temperature on the life cycle of D. nebulosa. D. nebulosa is considered a stenothermal species from a warm environment and has been reported in Texas and Florida, the West Indies, Mexico, Central America, and as far south as Brazil. According to the hypothesis of Hunter (1964), the capacity of this species for adaptation to different temperatures would not be expected to be as great as that of a eurythermal species. Stenothermal species are relatively limited by the environmental temperature, and therefore, one would expect a marked decrease in the length of the life cycle with increasing temperatures. On the other hand, eurythermal species are relatively independent of the environmental temperature, soa relatively less decrease in the length of the life cycle with increasing temperature would be expected.

It has been estimated by the Department of the Interior that by 1985 nearly one-quarter of all surface water in the United States will be used in removal of waste heat produced in electric generation. This will involve subjecting tremendous quantities of plankton to rapid fluctuations in temperature. The biological effect of such treatment on primary productivity and composition of zooplankton populations is not fully understood. To date little published information is available on the effect of rapid temperature fluctuations on plankton. Such temperatures are the result of heat exchange found in the cooling system of a steam-generating electric station. Patiria miniata is a dominant member of many subtidal and intertidal communities and consequently is an ecologically important species. Additionally, the adults can be induced to spawn throughout the year on demand, providing a constant source of larvae for experiments Larvae of P. miniata may be cultured from egg to juvenile in the laboratory with relative ease. The first 3 sections of this thesis describe techniques and baseline data used to conduct the primary experiment. The first section determines the minimum concentration of l-methyladenine required to induce spawning and if variations in quantity or concentrations had any significant effect on spawning times. Development and growth, the second section, sets limits for what will be considered “normal” larvae. The third section of this project describes the use of biological stains as a means to identify larvae receiving varying treatments when cultured en masse. The primary purpose and last section of this report is to answer the question how much of a thermal shock can the larvae of P. miniata withstand and still continue normal development.

No description available.

The cardiovascular system plays a vital role in protecting the body from temperature extremes due to its unique ability to store, transport, and dissipate heat. A comprehensive study of the thermoregulatory aspects of the system is severely limited by its complexity and the interdependency of its many component variables. Before a formal study can be initiated, certain fundamental properties of the cardiovascular system must be established and the physical processes associated with heat and mass transport must first be understood. To this end, over six hundred variables relating to the system's heat transport characteristics were identified. The variables were grouped to form dimensionless quantities using the Buckingham Pi Theorem. Each dimensionless quantity, or parameter, is composed of definable physical quantities that reflect the interaction between various components of the system. From the analysis, a series of reference scales was identified and, in turn, used to facilitate the physical interpretation of each resulting parameter. As a result of this analysis, a working set of physical and experimental quantities was derived to identify significant heat and mass transport processes involved in cardiovascular thermoregulation and to establish the relative rate at which these processes occur. / M.S.

Call number: LD2668 .T4 1961 I73

Call number: LD2668 .T4 1984 N37 / Master of Science

Call number: LD2668 .T4 1985 M62 / Master of Science

No description available.