Zoophysiology

I Olfactory Imprinting and Homing in Salmon.- 1 Notes on the Life History of Coho Salmon.- 1.1 The Magic Journey: Migration of Salmon.- 1.2 Homing.- 1.3 Functions of Homing.- 1.4 Life History of Coho Salmon.- 1.4.1 Alevin Stage.- 1.4.2 Fry and Fingerling Stages.- 1.4.3 Transformation from Parr to Smolt.- 1.4.4 Ocean Life: Migration to the Spawning Site.- 1.5 Evidence for Imprinting: Transplantation Experiments.- 1.5.1 Transplantation Before or During the Smolt Stage.- 1.5.2 Transplantation After Smolt Transformation.- 1.5.3 Transportation of Smolts.- 1.5.4 Coincidence of Imprinting and Smolt Transformation.- 1.5.5 Stocking of Salmon in the Great Lakes.- 1.5.6 Summary of Transplantation Experiments.- 2 Imprinting to Olfactory Cues: The Basis for Home-Stream Selection by Salmon.- 2.1 Early Investigations of the Olfactory Hypothesis.- 2.1.1 Laboratory Conditioning Experiments.- 2.1.2 Sensory-Impairment Experiments.- 2.1.3 Experiments on Olfactory Recognition of the Home Stream: Effects of Attractants and Repellents.- 2.1.4 Electrophysiological Studies.- 2.1.5 Criticisms of Early Investigations.- 2.2 Experiments with Artificially Imprinted Salmon.- 2.2.1 Experiments in Southern Lake Michigan - Imprinting Salmon with Morpholine.- 2.2.2 Experiments in Northern Lake Michigan - Imprinting Salmon to Morpholine or Phenethyl Alcohol.- 2.2.3 Ultrasonic Tracking.- 2.2.4 Electroencephalography.- 2.2.5 Electrocardiography: Conditioning the Heart Rate of Salmon as an Indicator to Their Response to Synthetic Chemicals.- 2.3 Natural Imprinting.- 2.4 Mechanisms of Olfactory Orientation in Upstream Migration.- 2.4.1 Overshooting and Proving: Positive and Negative Rheotaxis.- 2.4.2 Rheotropic Responses of Salmon to Tidal Currents.- 2.4.3 Rheotropic Responses of Salmon Imprinted to Synthetic Chemicals.- 2.5 Pheromones and Homing.- II Hormonal Regulation of Smolt Transformation and Olfactory Imprinting in Salmon.- 3 Factors Influencing Smolt Transformation: Effects of Seasonal Fluctuations in Hormone Levels on Transitions in Morphology, Physiology, and Behavior.- 3.1 Morphological, Physiological, and Behavioral Transitions.- 3.1.1 Development of Silvery Coloration.- 3.1.2 Downstream Migratory Activity.- 3.1.3 Salinity Tolerance and Osmoregulation.- 3.1.4 Osmoregulatory Correctional Mechanisms in Smolts: Gill Na+ /K+-ATPase Activity.- 3.1.5 Fish with Freshwater Life Cycles.- 3.2 Comparative Aspects of Smolt Transformation.- 3.3 Evidence for Hormonal Regulation of Smolt Transformation.- 3.4 Hormonal Influences on Olfactory Sensitivity, Learning, and Memory in Salmonids.- 4 Fluctuations in Hormone Levels During the Spawning Migration: Effects on Olfactory Sensitivity to Imprinted Odors.- 4.1 Effect of Sex Hormones on Olfactory Sensitivity and Discrimination.- 4.2 Physiological Mechanism for Countering Olfactory Adaptation.- 5 Thyroid Activation of Olfactory Imprinting in Coho Salmon.- 5.1 Methods for Studying Hormonal Regulation of Smolt Transformation.- 5.1.1 Natural Smolts.- 5.1.2 Hormonally Induced Smolt Transformation.- 5.1.3 Quantification of Smolt Transitions.- 5.1.4 Silvering and Loss of Parr Marks.- 5.1.5 Downstream Migratory Behavior.- 5.1.6 Salinity Tolerance and Osmoregulatory Capability.- 5.1.7 Gill Na+/K+-ATPase Activity.- 5.1.8 Hormone Radioimmunoassay.- 5.2 Results of Experiments on Hormonal Regulation of Smolt Transformation.- 5.3 Experiments with Rainbow Trout.- 5.4 Methods for Studying Endocrine Control of Olfactory Imprinting.- 5.5 Results of Experiments on Endocrine Control of Olfactory Imprinting.- 5.5.1 Behavioral Tests.- 5.5.2 Electrophysiological Tests.- 5.6 Organizational Influence of Thyroid Hormones on Maturation of the Central Nervous System.- 6 Endogenous and Environmental Control of Smolt Transformation.- 6.1 Size.- 6.2 Water Temperature.- 6.3 Daylength.- 6.4 Endocrine Mediation of Photoperiodic Cues.- 6.4.1 Thyroid Hormones.- 6.4.2 Osmoregulatory Hormones.- 6.4.3 Time-Keeping Role of the Pineal Gland.- 6.5 Endogenous Factors Regulating Smolt Transformation.- 6.6 Influence of Daylength on the Smoltification Process and the Production of Thyroid Hormones.- Postscript.- References.