Stress, including extreme or rapidly changing temperatures, are known to have deleterious effects on fish health and physiology. This thesis examines the combined effects of elevated acclimation temperature and acute handling stress on the number of antibody producing cells, plasma lysozyme concentrations, and the number of pronephric leukocytes in juvenile chinook salmon (Oncorhynchus tshawytscha). An additional goal of this thesis was to explore the effects of a temperature fluctuation, as a potential instigator of thermal shock, on innate immunity in wild fall chinook salmon of the Columbia River, specifically to determine if there are effects on plasma lysozyme concentrations and on the frequencies of lymphocytes, neutrophils, and thrombocytes in circulation. Finally, based on results found in an experiment involving elevated acclimation temperature, the relationship between the number of antibody producing cells and fish body weight was examined. Plasma lysozyme concentrations and the number of pronephric leukocytes were both affected by acclimation to 21°C compared to 13°C. While a positive relationship was found between temperature and lysozyme, an inverse relationship was found between temperature and the number of pronephric leukocytes. Plasma lysozyme concentrations, the number of pronephric leukocytes, and the number of antibody producing cells did not respond to the stressor, and the combination of elevated temperature and stress did not have an additive effect on any of the physiological or immunological variables studied. Differences between controls and temperature-treated fish were not detected among individual time points throughout a temperature fluctuation experiment, despite overall responses in plasma lysozyme concentrations and the frequencies of circulating lymphocytes. The frequencies of circulating neutrophils and thrombocytes did not respond to the thermal stressor. Finally, a significant positive relationship was detected between the number of antibody producing cells (assessed by a hemolytic plaque assay) and body weight among non-stressed fish acclimated to 21°C and 13°C. Regardless of acclimation temperature, these results emphasize the importance of the standardization of fish size for immunological experiments. Results from this thesis suggest that some components of innate immunity are affected by elevated acclimation temperatures and that the adaptive immune system is affected by acclimation temperature differently in small and large fish.

Every year, countless juvenile Pacific salmon leave streams and rivers on their migration to feeding grounds in the North Pacific Ocean and the Bering Sea. After periods ranging from a few months to several years, adult salmon enter rivers along the coasts of Asia and North America to spawn and complete their life cycle. Within this general outline, various life history patterns, both among and within species, involve diverse ways of exploiting freshwater, estuarine, and marine habitats. There are seven species of Pacific salmon. Five (coho, chinook chum, pink, and sockeye) occur in both North America and Asia. Their complex life histories and spectacular migrations have long fascinated biologists and amateurs alike. Physiological Ecology of Pacific Salmon provides comprehensive reviews by leading researchers of the physiological adaptations that allow Pacific Salmon to sustain themselves in the diverse environments in which they live. It begins with an analysis of energy expenditure and continues with reviews of locomotion, growth, feeding, and nutrition. Subsequent chapters deal with osmotic adjustments enabling the passage between fresh and salt water, nitrogen excretion and regulation of acid-base balance, circulation and gas transfer, and finally, responses to stress. This thorough and authoritative volume will be a valuable reference for students and researchers of biology and fisheries science as they seek to understand the environmental requirements for the perpetuation of these unique and valuable species.

When the first edition of Inland Fishes of California was published in 1976, it was a benchmark reference. Since that time, our knowledge of California's freshwater fishes has dramatically increased. This completely revised edition incorporates a vast amount of new information and creates a fresh synthesis of the historical data. Written by the leading expert on California's freshwater fishes and illustrated with beautiful line drawings, this compendium is the single best source for understanding and identifying the state's freshwater fishes. It is an essential resource for anyone who needs to have accurate and detailed information on California's fishes at their fingertips. Since the 1870s, the state's native fishes have been joined by thirty-four alien species, which now dominate many bodies of water. This book treats both native and introduced species, first in a key for identification, and then in individual species accounts covering characteristics, taxonomy, names, distribution, and life history. Each account includes the author's personal assessment of how well the species is doing and problems associated with its management. Most of the native fishes are found only in California and show many wonderful adaptations for living in the state's diverse waters. Unfortunately, many are also in danger of extinction. The message underlying the first edition of this book was that we knew astonishingly little about many of California's inland fishes. Although our knowledge is increasing, full accounts of some native fishes may not be complete before they become extinct. Preventing the loss of native fishes is the major goal of this book, and Moyle makes important suggestions for conservation strategies as well as presenting up-to-date information on ecology, life history, and distribution. With this knowledge, preserving our native fishes becomes possible even in the face of the state's growing economy and population.