Hopefully, this book will be taken off of the shelf frequently to be studied carefully over many years. More than 40 researchers were involved in this project, which examines respiration, circulation, and metabolism from ?sh to the land vertebrates, including human beings. A breathable and stable atmosphere ?rst appeared about 500 million years ago. Oxygen levels are not stable in aquatic environments and exclusively water-breathing ?sh must still cope with the ever-changing levels of O 2 and with large temperature changes. This is re?ected in their sophisticated count- current systems, with high O extraction and internal and external O receptors. 2 2 The conquest for the terrestrial environment took place in the late Devonian period (355–359 million years ago), and recent discoveries portray the gradual transitional evolution of land vertebrates. The oxygen-rich and relatively stable atmospheric conditionsimpliedthatoxygen-sensingmechanismswererelativelysimpleandl- gain compared with acid–base regulation. Recently, physiology has expanded into related ?elds such as biochemistry, molecular biology, morphology and anatomy. In the light of the work in these ?elds, the introduction of DNA-based cladograms, which can be used to evaluate the likelihood of land vertebrates and lung?sh as a sister group, could explain why their cardio-respiratory control systems are similar. The diffusing capacity of a duck lung is 40 times higher than that of a toad or lung?sh. Certainly, some animals have evolved to rich high-performance levels.

This presentation describes various aspects of the regulation of tissue oxygenation, including the roles of the circulatory system, respiratory system, and blood, the carrier of oxygen within these components of the cardiorespiratory system. The respiratory system takes oxygen from the atmosphere and transports it by diffusion from the air in the alveoli to the blood flowing through the pulmonary capillaries. The cardiovascular system then moves the oxygenated blood from the heart to the microcirculation of the various organs by convection, where oxygen is released from hemoglobin in the red blood cells and moves to the parenchymal cells of each tissue by diffusion. Oxygen that has diffused into cells is then utilized in the mitochondria to produce adenosine triphosphate (ATP), the energy currency of all cells. The mitochondria are able to produce ATP until the oxygen tension or PO2 on the cell surface falls to a critical level of about 4–5 mm Hg. Thus, in order to meet the energetic needs of cells, it is important to maintain a continuous supply of oxygen to the mitochondria at or above the critical PO2 . In order to accomplish this desired outcome, the cardiorespiratory system, including the blood, must be capable of regulation to ensure survival of all tissues under a wide range of circumstances. The purpose of this presentation is to provide basic information about the operation and regulation of the cardiovascular and respiratory systems, as well as the properties of the blood and parenchymal cells, so that a fundamental understanding of the regulation of tissue oxygenation is achieved.

The Cardiovascular System: Design, Control and Function, Volume 36A, a two- volume set, not only provides comprehensive coverage of the current knowledge in this very active and growing field of research, but also highlights the diversity in cardiovascular morphology and function and the anatomical and physiological plasticity shown by fish taxa that are faced with various abiotic and biotic challenges. Updated topics in this important work include chapters on Heart Morphology and Anatomy, Cardiomyocyte Morphology and Physiology, Electrical Excitability of the Fish Heart, Cardiac Energy Metabolism, Heart Physiology and Function, Hormonal and Intrinsic Biochemical Control of Cardiac Function, and Vascular Anatomy and Morphology. In addition, chapters integrate molecular and cellular data with the growing body of knowledge on heart and in vivo cardiovascular function, and as a result, provide insights into some of the most important questions that still need to be answered. - Presents a comprehensive overview of cardiovascular structure and function in fish - Covers topics in a way that is ideal for researchers in fish physiology and for audiences within the fields of comparative morphology, histology, aquaculture and ecophysiology - Provide insights into some of the most important questions that still need to be answered

How do vertebrates get the oxygen they need, or even manage without it for shorter or longer periods of time? How do they sense oxygen, how do they take it up from water or air, and how do they transport it to their tissues? Respiratory system adaptations allow numerous vertebrates to thrive in extreme environments where oxygen availability is limited or where there is no oxygen at all. Written for students and researchers in comparative physiology, this authoritative summary of vertebrate respiratory physiology begins by exploring the fundamentals of oxygen sensing, uptake and transport in a textbook style. Subsequently, the reader is shown important examples of extreme respiratory performance, like diving and high altitude survival in mammals and birds, air breathing in fish, and those few vertebrates that can survive without any oxygen at all for several months, showing how evolution has solved the problem of life without oxygen.

Biology and Physiology of Freshwater Neotropical Fish is the all-inclusive guide to fish species prevalent in the neotropical realm. It provides the most updated systematics, classification, anatomical, behavioral, genetic, and functioning systems information on freshwater neotropical fish species. This book begins by analyzing the differences in phylogeny, anatomy, and behaviour of neotropical fish. Systems such as cardiovascular, respiratory, renal, digestive, reproductive, muscular, and endocrine are described in detail. This book also looks at the effects of stress on fish immune systems, and how color and pigmentation play into physiology and species differentiation. Biology and Physiology of Freshwater Neotropical Fish is a must-have for fish biologists and zoologists. Students in zoology, ichthyology, and fish farming will also find this book useful for its coverage of some of the world's rarest and least-known fish species. - Features chapters written by top neotropical fish researchers and specialists - Discusses environmental effects on neotropical fishes, including climate change and pollution - Details the phylogenetic occurrence of electroreceptors and electric organs in fish

The papers in this volume were presented at an international symposium, held in South Australia on September 8-10, 1983. The purpose of the meeting was to present the comparative physiology of gas exchange, water balance and energet ics of developing vertebrate embryos. contributions were invited from leading research workers in an attempt to represent the forefront of investigation of all vertebrate classes and to promote a broadly comparative approach to the study of embryonic physiology. These proceedings therefore reflect the current level of research activity focus ing on each group of vertebrates. While considerable expansion and specializa tion has occurred in the area of avian embryos over the last decade, work on reptilian embryos is less developed and that on fish and amphibians is still in its infancy. Although a great deal is known about respiration and metabolism in embryos of placental mammals, the physiology associated with the curious mode of development of monotreme and marsupial embryos has not been examined until recently. In this symposium. the well-studied vertebrate classes are repre sented primarily by specific research papers that document original work. These are balanced by more extensive reviews of the lesser known classes.