B.G. Kapoor – författare

Each organism has its own internal biological clock, which is reset by environmental cues (Zeitgebers), thus keeping it synchronized with the external environment. It is a chemically based oscillating system within cells, relying on molecular feedback loops. Circadian biological clocks exist in most organisms.What is so special about the clock in fish? Where is it located—in the retina, inside the brain, or in the pineal? What is the molecular basis of its function? How is the clock able to keep time in the absence of environmental cues?Although biological clocks have been intensively studied over the past four decades, only recently have the tools needed to examine the molecular basis of circadian rhythms become available. This book reviews the state of knowledge in sufficient detail and presents the latest contributions to the field, showing fish provide a unique model of the circadian biological clock.

In most habitats, adaptations are the single most obvious aspects of an organism’s phenotype. However, the most obvious feature of many subterranean animals are losses, not adaptations. Even Darwin saw subterranean animals as degenerates: examples of eyelessness and loss of structure in general. For him, the explanation was a straightforward Lamarckian one, and one that did not involve adaptation and the struggle of existence. This volume is a comprehensive account of all known species of subterranean fishes. It includes an extensive introduction, history of investigations, consideration of non-stygobitic fishes in caves, and detailed analysis of the conservation status of these very rare animals.

Fish comprise more than 50 of all living vertebrates and are found in a wide range of highly diverse habitats like the deep sea, the shoreline, tide pools, tropical streams and sweetwater ponds. During evolution, the senses of fish have adapted to the physical conditions of the environment in which different species live. As a result, the senses of fish exhibit a remarkable diversity that allows different species to deal with the physical constraints imposed by their habitat. In addition, fish have evolved several 'new' sensory systems that are unique to the aquatic environment. In this book, examples of adaptation and refinement are given for six sensory systems: In each case, the environmental conditions under which a particular group of fish lives are analyzed. This is followed by a description of morphology and physiology of the sensory system and by an evaluation of its perceptional capabilities. Finally, the sensory adaptations to the particular conditions that prevail in the habitat of a species are highlighted.The various examples from different groups of fish presented in this book demonstrate the impressive capability of fish sensory systems to effectively overcome physical problems imposed by the environment.

This book deals with chemosensory systems of fishes and covers the well known olfactory and the gustatory senses as well as the less popular solitary chemosensory cells. Chemosenses play an essential role in the life of a fish. They help fish in their search for food, to consume it and digest it. They also help fish to find their conspecifics and to avoid enemies or predators. Fish live in varied and often extreme ecological conditions frequently inhabiting niches such as caves or at great depths in the oceans. The chemosensory organs of such well adapted fish are highly specialized and evolved in contrast to the chemosenses of sight-hunting fish. Fishes have developed diverse strategies to survive within the widely varying water bodies, owing, at least in part, to the highly evolved chemosensory systems. A group of internationally reputed specialists have contributed to this book. It contains six chapters devoted to fish olfaction, one chapter to solitary chemosensory cells and six chapters to the fish taste

A compilation of the development of non-teleost fishes has so far been unavailable. These fishes include the jawless fishes (hagfish and lampreys), the cartilaginous fishes (sharks, rays, skates and chimaeras), the forerunners of the teleostei: the cladistia (bichirs and reedfish), the chondrostei (sturgeon and paddlefish, the neopterygii (gar pike and bowfin), and, finally, the closest relations to the tetrapods: the lungfishes (the coelacanh [ living fossil], Protopterus of Africa, Lepidosiren of South America and Neoceratodus of Australia). Therefore, the present volume has been devoted to closing the gap by an up-to-date scientific review of the early life-history of these non-teleost fishes (agnathi excepted).

In most habitats, adaptations are the single most obvious aspects of an organism’s phenotype. However, the most obvious feature of many subterranean animals are losses, not adaptations. Even Darwin saw subterranean animals as degenerates: examples of eyelessness and loss of structure in general. For him, the explanation was a straightforward Lamarckian one, and one that did not involve adaptation and the struggle of existence. This volume is a comprehensive account of all known species of subterranean fishes. It includes an extensive introduction, history of investigations, consideration of non-stygobitic fishes in caves, and detailed analysis of the conservation status of these very rare animals.

Each organism has its own internal biological clock, which is reset by environmental cues (Zeitgebers), thus keeping it synchronized with the external environment. It is a chemically based oscillating system within cells, relying on molecular feedback loops. Circadian biological clocks exist in most organisms.What is so special about the clock in fish? Where is it located—in the retina, inside the brain, or in the pineal? What is the molecular basis of its function? How is the clock able to keep time in the absence of environmental cues?Although biological clocks have been intensively studied over the past four decades, only recently have the tools needed to examine the molecular basis of circadian rhythms become available. This book reviews the state of knowledge in sufficient detail and presents the latest contributions to the field, showing fish provide a unique model of the circadian biological clock.

In recent years, progress in fish biology has advanced at an unprecedented rate and has led to many breakthroughs in the field. This book provides a wealth of information on the strategies that fish adopt with respect to waters with markedly different physical and chemical characteristics. It shows how their physiology, behaviour and lifestyles are adapted to exploit particular niches and gives comprehensive insight into fish life under extreme conditions. The readers are introduced to the ways in which fish exemplify many phenomena of general biological interest - the existence of competitors, chaos, and predator-prey interaction. Fish pathology as well as the components of the immune system are addressed.In this book, original and at times controversial views are presented, areas which have so far received inadequate attention are highlighted and avenues for further research are suggested.