Download or read book Reproduction in Female Diploid and Triploid Eastern Oysters Crassostrea Virginica written by Esther Faith Young and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Relationship Between Reproduction and Mortality in Triploid Crassostrea Virginica written by Joseph L. Matt and published by . This book was released on 2018 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unusual mortalities of cultured Crassostrea virginica in late spring have been reported from farms in the Chesapeake Bay from 2014 to 2017. None of the usual causes (e.g. disease, poor husbandry) were likely responsible, and mortalities occurred without clear signs of biological or physical stressors. Mortalities in the spring of 2014 were particularly high on over a dozen farms in Virginia, most of which were on the bayside of the Eastern Shore. Estimated losses were over 50%; however, mortalities only occurred within a four-week period between mid-May and early June. Farmers that had unusually high mortality in their crop were exclusively growing triploid oysters, which implicated triploidy as an important factor and even led to calling these events "triploid mortality." Many affected farmers were also growing a "northern cross," oysters made by crossing brood stock from New England to brood stock from Virginia, and relatively high fecundity was found in some triploid oysters sampled from these farms. It was hypothesized that the genetic contribution from the New England parent of the northern cross was causing aberrant gametogenesis in triploid oysters during the late spring, and that this caused triploid mortality. A controlled field test was conducted to evaluate this hypothesis and to further examine the role of genetics and gametogenesis in triploid mortality. to investigate the effect that ploidy and brood stock origin have on susceptibility to triploid mortality, four triploid and four diploid types of oysters, produced by crossing different combinations of brood stock of Virginia, Louisiana, and Maine origin, were deployed to three commercial oyster farms that experienced unusually high mortality in 2014, as well as to a control site lacking reports of unusual spring mortality. The survival and growth of oysters from each group were measured throughout the spring and summer of 2016. A mortality event (>20% mortality) was observed in late spring at one site. The mortality event was only associated with triploid groups, with cumulative mortality ranging from 12 to 24% among groups. Mortality in the "northern cross" was not especially high (23%). The effect that gametogenesis had on the mortalities was investigated by examining histological cross sections of triploid and diploid oysters from the site where triploid mortality occurred, as well as from the control site where there was no triploid mortality. Diploid oysters at the affected site became gravid and spawned earlier than diploid oysters at the control site. Gonad development in triploid oysters was abnormal and variable, so categories were developed for classifying gonad development in triploid oysters and making comparisons between sites. No obvious difference was observed in gonad development between triploid oysters at the two sites. Cross-sections from male triploids did not typically contain any spermatozoa, and cross sections from females usually contained only a few oocytes. Gonad development may not be strongly associated with triploid mortality, but the physiology associated with abnormal gametogenesis in triploid oysters could be a major contributing factor. More work is needed on the physiological consequences of gametogenesis in triploid oysters to explain triploid mortality.
Download or read book Effect of Estradiol 17B on the Gonadal Developemnt of Diploid and Triploid Female Eastern Oysters written by Roberto Quintana and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonnative Oysters in the Chesapeake Bay written by National Research Council and published by National Academies Press. This book was released on 2004-03-09 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonnative Oysters in the Chesapeake Bay discusses the proposed plan to offset the dramatic decline in the bay's native oysters by introducing disease-resistant reproductive Suminoe oysters from Asia. It suggests this move should be delayed until more is known about the environmental risks, even though carefully regulated cultivation of sterile Asian oysters in contained areas could help the local industry and researchers. It is also noted that even though these oysters eat the excess algae caused by pollution, it could take decades before there are enough of them to improve water quality.
Download or read book Fisheries of the United States 2007 written by and published by Government Printing Office. This book was released on 1976 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ASSESSMENT OF MAJOR FACTORS AFFECTING TRIPLOID INDUCTION USING HYDROSTATIC PRESSURE AND GROWTH ASSESSMENT OF TRIPLOID EASTERN OYSTERS CRASSOSTREA VIRGINICA WITHIN THE BRAS D OR LAKE written by Ian Sewell and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Triploid oysters can be created through chemical or pressure treatments that induce a diploid embryo to become a triploid by blocking the expulsion of a polar body during development. Triploid oysters are desirable because they are sterile, faster growing, and have more energy to fight pathogens. Little is known about triploid induction in the Eastern oyster using hydrostatic pressure. The focus of these experiments were to evaluate different variables to elucidate their impact on triploid induction and assess the growth of triploid Eastern oysters grown in Canadian waters. The first objective of this study was to determine the most efficient pressure intensity and duration treatments that would yield the highest triploidy induction rates in the Eastern oyster. The second objective was to compare the growth of triploid vs diploid oysters in field conditions in the Bras d'Or lake, Nova Scotia.
Download or read book Performance of Triploid Eastern Oysters Crassostrea Virginica in Mobile Bay Alabama written by James William Anderson and published by . This book was released on 2000 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reproductive Success in Hatchery produced Eastern Oyster Crassostrea Virginica gmelin written by April Piggott and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The eastern oyster (Crassostrea virginica Gmelin 1791) has great ecological and economic importance but populations have declined, especially in Chesapeake Bay, to historically low numbers. Hatcheries strive to produce oysters with beneficial characteristics for supplementation and commercial purposes, both natural and stimulated mass spawning. Unequal contribution of parents in mass spawnings potentially can lead to high levels of inbreeding and a loss of beneficial characteristics in offspring. In this study, we determined microsatellite genotypes for parents (n^parents =24, 49, and 77 parents) and progeny (n=96 each) of three hatchery-produced families and used the data for parental assignment. We observed the presence of more than two alleles per locus for some offspring, yet because genetic analysis software only allows for a maximum of two alleles per locus, we chose the two alleles with the strongest signals. For the three parent "populations" 71% of alleles had frequencies of 0.05 and observed heterozygosities were lower than expected by an average factor of 0.27. Inbreeding within the various parent populations was similar across the three families ranging from F^IS 0.26 - 0.43. In all three families, the offspring exhibited greater levels of genetic diversity and lower inbreeding levels than the parents (F^IS 0.14-0.21), and in some cases offspring exhibited alleles that were not present in the parents. Variance in the number of offspring produced per parent was observed for all families and in general,
Download or read book The Eastern Oyster written by Victor S. Kennedy and published by University of Maryland Sea Grant Publications. This book was released on 1996 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1966 Congress passed the National Sea Grant College Program Act to promote marine research, education, and extension services in institutions along the nation's ocean and Great Lakes coasts. In Maryland a Sea Grant Program -- a partnership among federal and state governments, universities, and industries -- began in 1977, and in 1982 the University of Maryland was named the nation's seventeenth Sea Grant College. The Maryland Sea Grant College focuses its efforts on the Chesapeake Bay, with emphasis on the marine concerns of fisheries, seafood technology, and environmental quality. The first comprehensive review of the biology of the eastern oyster in more than thirty years. The twenty-one chapters synthesize every aspect of oyster biology -- for instance, general anatomy, physiology, the circulatory system, reproduction, genetics, diseases -- and issues related to management and aquaculture.
Download or read book Marine Bivalve Molluscs written by Elizabeth Gosling and published by John Wiley & Sons. This book was released on 2015-07-07 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine Bivalve Molluscs Marine Bivalve Molluscs is a comprehensive and thoroughly updated Second Edition of Bivalve Molluscs, covering all major aspects of this important class of invertebrates. As well as being an important class biologically and ecologically, many of the bivalves are fished and cultured commercially (e.g. mussels, oysters, scallops and clams) in a multi-billion dollar worldwide industry. Elizabeth Gosling has written a landmark book that will stand for many years as the standard work on the subject. Chapters in Marine Bivalve Molluscs cover morphology, ecology, feeding, reproduction, settlement and recruitment, growth, physiology, fisheries, aquaculture, genetics, diseases and parasites, and public health issues. A full understanding of many of these aspects is vital for all those working in bivalve fisheries and culture. An essential purchase for anyone concerned with this important class of animals, copies of Marine Bivalve Molluscs should be on the shelves of biologists, ecologists, environmental scientists, fisheries scientists and personnel within the aquaculture industry. Copies of the book should be available in all libraries and research establishments where these subjects are studied or taught. REVIEWS OF THE FIRST EDITION An admirable achievement...a valuable addition to marine sciences libraries everywhere. The back cover of this book says that it is a landmark text that will stand for many years as the standard work on this subject. I can only agree with this sentiment. ~ Aquaculture A welcome addition to the literature and provides the reader with a comprehensive overview of biological and environmental factors that affect and control both natural populations of marine bivalves and culture operations. ~ Aquaculture International The author has done an admirable job in compiling a wealth of information into a readable text. ~ Transactions of the American Fisheries Society Will serve well as a description of much of both the experimental biology and the aquaculture of bivalves. ~ Journal of Experimental Marine Biology and Ecology Provides excellent reviews of all major aspects...an extremely important reference for anyone engaged in bivalve research, fisheries management, and aquaculture. ~ Quarterly Review of Biology The book is very readable, in an easy style. It is well illustrated and there is a wealth of data and statistics presented. ~ Bulletin of the Malacological Society of London
Download or read book Selective Breeding in Aquaculture an Introduction written by Trygve Gjedrem and published by Springer Science & Business Media. This book was released on 2010-03-17 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The foundation of quantitative genetics theory was developed during the last century and facilitated many successful breeding programs for cultivated plants and t- restrial livestock. The results have been almost universally impressive, and today nearly all agricultural production utilises genetically improved seed and animals. The aquaculture industry can learn a great deal from these experiences, because the basic theory behind selective breeding is the same for all species. The ?rst published selection experiments in aquaculture started in 1920 s to improve disease resistance in ?sh, but it was not before the 1970 s that the ?rst family based breeding program was initiated for Atlantic salmon in Norway by AKVAFORSK. Unfortunately, the subsequent implementation of selective breeding on a wider scale in aquaculture has been slow, and despite the dramatic gains that have been demonstrated in a number of species, less than 10% of world aquaculture production is currently based on improved stocks. For the long-term sustainability of aquaculture production, there is an urgent need to develop and implement e- cient breeding programs for all species under commercial production. The ability for aquaculture to successfully meet the demands of an ever increasing human p- ulation, will rely on genetically improved stocks that utilise feed, water and land resources in an ef?cient way. Technological advances like genome sequences of aquaculture species, and advanced molecular methods means that there are new and exciting prospects for building on these well-established methods into the future.
Download or read book Animal Biotechnology written by National Research Council and published by National Academies Press. This book was released on 2002-12-29 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Genetic-based animal biotechnology has produced new food and pharmaceutical products and promises many more advances to benefit humankind. These exciting prospects are accompanied by considerable unease, however, about matters such as safety and ethics. This book identifies science-based and policy-related concerns about animal biotechnologyâ€"key issues that must be resolved before the new breakthroughs can reach their potential. The book includes a short history of the field and provides understandable definitions of terms like cloning. Looking at technologies on the near horizon, the authors discuss what we know and what we fear about their effectsâ€"the inadvertent release of dangerous microorganisms, the safety of products derived from biotechnology, the impact of genetically engineered animals on their environment. In addition to these concerns, the book explores animal welfare concerns, and our societal and institutional capacity to manage and regulate the technology and its products. This accessible volume will be important to everyone interested in the implications of the use of animal biotechnology.
Download or read book Sex Control in Aquaculture written by Hanping Wang and published by John Wiley & Sons. This book was released on 2018-11-08 with total page 1810 pages. Available in PDF, EPUB and Kindle. Book excerpt: Awarded Bookauthority's "Best Aquaculture Books of all Time" A comprehensive resource that covers all the aspects of sex control in aquaculture written by internationally-acclaimed scientists Comprehensive in scope, Sex Control in Aquaculture first explains the concepts and rationale for sex control in aquaculture, which serves different purposes. The most important are: to produce monosex stocks to rear only the fastest-growing sex in some species, to prevent precocious or uncontrolled reproduction in other species and to aid in broodstock management. The application of sex ratio manipulation for population control and invasive species management is also included. Next, this book provides detailed and updated information on the underlying genetic, epigenetic, endocrine and environmental mechanisms responsible for the establishment of the sexes, and explains chromosome set manipulation techniques, hybridization and the latest gene knockout approaches. Furthermore, the book offers detailed protocols and key summarizing information on how sex control is practiced worldwide in 35 major aquaculture species or groups, including fish and crustaceans, and puts the focus on its application in the aquaculture industry. With contributions from an international panel of leading scientists, Sex Control in Aquaculture will appeal to a large audience: aquaculture/fisheries professionals and students, scientists or biologists working with basic aspects of fish/shrimp biology, growth and reproductive endocrinology, genetics, molecular biology, evolutionary biology, and R&D managers and administrators. This text explores sex control technologies and monosex production of commercially-farmed fish and crustacean species that are highly in demand for aquaculture, to improve feed utilization efficiency, reduce energy consumption for reproduction and eliminate a series of problems caused by mixed sex rearing. Thus, this book: Contains contributions from an international panel of leading scientists and professionals in the field Provides comprehensive coverage of both established and new technologies to control sex ratios that are becoming more necessary to increase productivity in aquaculture Includes detailed coverage of the most effective sex control techniques used in the world's most important commercially-farmed species Sex Control in Aquaculture is the comprehensive resource for understanding the biological rationale, scientific principles and real-world practices in this exciting and expanding field.
Download or read book Selection and Breeding Programs in Aquaculture written by Trygve Gjedrem and published by Springer Science & Business Media. This book was released on 2005-04-13 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although aquaculture as a biological production system has a long history, systematic and efficient breeding programs to improve economically important traits in the farmed species have rarely been utilized until recently, except for salmonid species. This means that the majority of aquaculture production (more than 90 %) is based on genetically unimproved stocks. In farm animals the situation is vastly different: practically no terrestrial farm production is based on genetically unimproved and undomesticated populations. This difference between aquaculture and livestock production is in spite of the fact that the basic elements of breeding theory are the same for fish and shellfish as for farm animals. One possible reason for the difference is the complexity of reproductive biology in aquatic species, and special consideration needs to be taken in the design of breeding plans for these species. Since 1971 AKVAFORSK, has continuously carried out large scale breeding research projects with salmonid species, and during the latest 15 years also with a number of fresh water and marine species. Results from this work and the results from other institutions around the world have brought forward considerable knowledge, which make the development of efficient breeding programs feasible. The genetic improvement obtained in selection programs for fish and shellfish is remarkable and much higher than what has been achieved in terrestrial farm animals.
Download or read book Aquaculture and Fisheries Biotechnology written by Rex A. Dunham and published by CABI. This book was released on 2023-02-28 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt: The genetic improvement of fish for aquaculture and related fisheries has seen huge advances over recent years. Building upon the previous two editions of Aquaculture and Fisheries Biotechnology: Genetic Approaches, this 3rd edition offers a presentation of traditional selective breeding, modern genetic biotechnology, genomics, gene transfer and gene editing, and the latest developments in genetic biotechnology such as epigenetics, xenogenesis and genome-wide association study coupled with commercial application, the impact of government regulation and expectations for the future. It provides a firm grounding in relevant aspects of classical genetics, before focusing on particular aspects such as sex reversal and breeding as applied in aquaculture and fisheries. It also explores how more recent molecular genetics, genomics and biotechnology techniques can be used and combined in improvement programmes for fish and aquaculture species. A glossary explains the latest terminology used in biotechnology and genetics. This book will be useful for research scientists and students in marine biotechnology, aquaculture biotechnology, and fish genetics and breeding.
Download or read book Bivalve Molluscs written by Elizabeth Gosling and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bivalve Molluscs is an extremely comprehensive book coveringall major aspects of this important class of invertebrates. As wellas being an important class biologically and ecologically, many ofthe bivalves are fished and cultured commercially (e.g. mussels,oysters, scallops and clams) in a multi-billion dollar worldwideindustry. Elizabeth Gosling who has a huge wealth of research, teachingand hands on experience working with bivalves, has written alandmark book that will stand for many years as the standard workon the subject. Chapters in Bivalve Molluscs covermorphology, ecology, feeding, reproduction, settlement andrecruitment, growth, physiology, fisheries, aquaculture, genetics,diseases and parasites, and public health issues. A fullunderstanding of many of these aspects is vital for all thoseworking in bivalve fisheries and culture. An essential purchase for anyone concerned with this importantclass of animals, copies of Bivalve Molluscs should be onthe shelves of biologists, ecologists, environmental scientists,fisheries scientists and personnel within the aquaculture industry.Copies of the book should be available in all libraries andresearch establishments where these subjects are studied ortaught. Elizabeth Gosling is based at the Galway-Mayo Instituteof Technology, Galway, Ireland.
Download or read book Aquaculture Genome Technologies written by Zhanjiang (John) Liu and published by John Wiley & Sons. This book was released on 2008-02-28 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: Genomics is a rapidly growing scientific field with applications ranging from improved disease resistance to increased rate of growth. Aquaculture Genome Technologies comprehensively covers the field of genomics and its applications to the aquaculture industry. This volume looks to bridge the gap between a basic understanding of genomic technology to its practical use in the aquaculture industry.
