This book is the first comprehensive description of development of the Acipenserid fish published in the English language. It con tains the results of more than 40 years of studies by the authors and their colleagues. My own life in science has been intimately related both with the authors and the fish, which are the subject of this book. Therefore, it gives me a great pleasure to present to the English reader an expanded version of the book. Those interested in the history of biology must be well aware of the fact that genetics in the USSR was practically demolished by Lysenko at the session of the Lenin All-Union Academy of Agricultural Sciences in 1948. However, it is much less well known that other fundamental branches of biology were also persecuted at that time, experimental embryology (developmental mechanics) among them. As a result, many embryologists, in cluding the authors of this book, were forced to turn to more ap plied problems, this being the only way to continue research. They had to abandon amphibians and concentrate their efforts on sturgeon.

1 Oocyte Maturation and Ovulation

1.1 Maturation of Sturgeon Oocytes in Nature and at the Hatcheries
1.2 Changes in the Oocytes During Their Maturation
1.3 Ovulation of the Oocytes and the Formation of Coelomic Fluid
1.4 Hormonal Stimulation of Oocyte Maturation and Ovulation
1.5 Methods of Working with Sturgeon Spawners Migrating in Rivers at Different Seasons and Spawning During the Same or Following Year
1.6 Introduction in Culture of Various Acipenserid Species
1.7 Influence of Environmental Conditions on the Capacity of Females to Respond to Pituitary Injection and the Hatchery Quality of Eggs
1.8 Release of Eggs During Natural Spawning, Time of Oocyte Maturation and Ovulation and Time of Obtaining Eggs at Hatcheries
2 Embryonic Development
2.1 Gametes
2.2 Artificial Insemination of Eggs
2.3 Fertilization
2.4 Cleavage and Blastulation
2.5 Gastrulation
2.6 Development of the Embryo from the End of Gastrulation to the Onset of Heart Beating
2.7 Development of the Embryo from the Onset of Heart Beating to the Time of Hatching
2.8 Duration and Rate of Embryogenesis in Various Acipenserid Species and Their Dependence on Temperature. Chronology of Development
3 Development of Prelarvae
3.1 Characteristics of the Prelarval Period of Development
3.2 Stages of Prelarval Development
3.3 Timing of Prelarval Development
3.4 Prelarval Development During the Period Between Hatching and up to the Beginning of Rhythmic Respiratory Movements
3.5 Development of Prelarvae from the Beginning of Rhythmic Respiratory Movements and up to Transition to Active Feeding
3.6 Differences Between Prelarvae of Different Sturgeon Species A. gueldenstaedti H. huso, A. stellatus, A. ruthenus, P. kaufmanni
3.7 Defects of Prelarval Development
4 Environmental Conditions of Spawning and Development
4.1 General
4.2 Temperature Range
4.3 Oxygen Content of Water and Gas Metabolism in Embryos
4.4 Light Conditions
4.5 Quality of Water
4.6 The Range of the Ecological Optimum
5 Control of Incubation Conditions
5.1 General
5.2 Duration of Development as a Criterion for the Evaluation of Incubation Conditions
5.3 Normal Embryonic and Prelarval Development
5.4 Losses During Incubation, Their Magnitude and Sources
Appendix A Quick Method for the Determination of Gonad Maturity in the Sturgeon (Kazanskii et al. 1978)
Appendix B Duration of Oocyte Maturation Time in Vitro as a Criterion for Selecting Sturgeon Spawners for Breeding (B.E Goncharov)
Appendix C Comparative Quantitative Determination of the Gonadotropic Activity in Sturgeon Pituitaries (Goncharov 1972)
Appendix D Relative Characteristic of Developmental Duration
Appendix E Determination of Time for Injection of Pituitary Suspension and Inspection of Females After Pituitary Injection for Obtaining Eggs at the Optimal Time at Different Temperatures
E.2 Determination of Time for Inspection of Females and Collecting Eggs
E.3 Example for Calculation of the Maturation Time and Time of Female Inspection
Appendix F Artificial Insemination of Sturgeon Eggs (Ginsburg 1963)
Appendix G Sampling for Determination of Fertilization Percentage, Extent of Losses, and Percentage of Abnormal Embryos
Plates I-XX
Abbreviations for Figures and Plates
References.