Patrick Williot – författare

Most of the diadromous fish of the world have decreased in distribution and abundance since the beginning of the twentieth century. They are now threatened, and important conservation issues arise. The causes of these trends vary among species and basins but regional human impact (damming, pollution, fisheries) and global change (climate) are suspected to be responsible for these difficulties. This book contains selected papers from an international symposium organised by the Diadfish network held in Bordeaux (France) in 2005. Readers will find up-to-date information on the ecology, ecotoxicology and physiology of several diadromous species (Atlantic salmon, shads, lampreys, eels) and this whole group in Europe. Main impacts are also documented and analysed in case studies, and solutions or remediation actions are presented.

The biology of the Siberian sturgeon, Acipenser baerii Brandt 1869, has become a very attractive subject of investigation for biologists since the 1980s. This volume 1 is part of a two-volume set devoted to the species, the second of which focuses on farming. The present volume is divided into three parts: Biology and ecology, Biology and physiology of reproduction, and Ecophysiology, i.e. adaptation to the environment. The first part addresses a broad range of topics, such as: the ecology, including a new approach to species-specificity, a new insight on the mineralization of vertebral elements, two approaches to sex determination, transposable elements in the gonads, early ontogeny, olfaction and gustation, nutrition and swimming. The second part includes neurochemical and anatomical descriptions of the central nervous system and an updated version of the oogenesis, the characteristics of both sperm and spermatozoa, and a synthesis on gonadal steroids (synthesis, plasmatic levels and biological activities). In turn, the third part reveals how the physiology of the species changes depending on environmental factors such as oxygen, ammonia, and nitrite. Some fundamental consequences of ammonia are developed (sublethal and lethal levels, effects on gill epithelium and haematology, acid-base balance, on AA and adenyl nucleotides levels in plasma, brain and muscle tissue). In addition, the book includes two methodological chapters dealing with fish dorsal aortic cannulation and respiration physiology.

The biology of the Siberian sturgeon, Acipenser baerii Brandt 1869, has become a very attractive subject of investigation for biologists since the 1980s. This volume 1 is part of a two-volume set devoted to the species, the second of which focuses on farming. The present volume is divided into three parts: Biology and ecology, Biology and physiology of reproduction, and Ecophysiology, i.e. adaptation to the environment. The first part addresses a broad range of topics, such as: the ecology, including a new approach to species-specificity, a new insight on the mineralization of vertebral elements, two approaches to sex determination, transposable elements in the gonads, early ontogeny, olfaction and gustation, nutrition and swimming. The second part includes neurochemical and anatomical descriptions of the central nervous system and an updated version of the oogenesis, the characteristics of both sperm and spermatozoa, and a synthesis on gonadal steroids (synthesis, plasmatic levels and biological activities). In turn, the third part reveals how the physiology of the species changes depending on environmental factors such as oxygen, ammonia, and nitrite. Some fundamental consequences of ammonia are developed (sublethal and lethal levels, effects on gill epithelium and haematology, acid-base balance, on AA and adenyl nucleotides levels in plasma, brain and muscle tissue). In addition, the book includes two methodological chapters dealing with fish dorsal aortic cannulation and respiration physiology.

The Siberian sturgeon, Acipenser baerii Brandt 1869 is the most widely farmed sturgeon species. Continuing from Volume 1, which focuses on the biology of the species, the present Volume 2 in turn examines farming aspects. It is divided into six parts, the first of which deals with reproduction and early ontogenesis, i.e. reproductive cycles, controlled reproduction, sperm cryoconservation, and weaning of larvae. The second covers the growing phase with a focus on food and feeding (management, fish meal replacement, potential endocrine disruptions, usefulness of prebiotics and immunostimulants, and nitrogen excretion). Production-related data are the focus of the third part and include: characteristics (countries, structures of production, evolution in production, economic features) of the gross production of the species (meat and caviar) worldwide, a method for assessing the quality of caviars, off-flavors management, and an example of production of fingerlings for restocking. Part four addresses selected long-term management issues: genetic variability of brood stocks, genome manipulation and sex control, and the advantages of hybrids. The next three chapters constitute the fifth part, which is devoted to health status (immunology and welfare). In closing, the absence of ecological risks of introducing the species in non-native waters is shown using two long-term documented examples (Russia and France). Three methodological chapters round out the volume, covering: in vitro incubation of ovarian follicles, a richly illustrated library of echographies and photos, and a detailed presentation of oxygen demand studies.

As the species occurred in sympatry with Acipenser oxyrinchus in Germany and Poland and very recently in France as well, a brief outlook on restoration-management programs of A. oxyrinchus are also provided for both North America and Northern European countries, namely Germany and Poland.

As the species occurred in sympatry with Acipenser oxyrinchus in Germany and Poland and very recently in France as well, a brief outlook on restoration-management programs of A. oxyrinchus are also provided for both North America and Northern European countries, namely Germany and Poland.