Cryopreservation Of Fish Eggs And Sperm

Understanding the reproductive physiology and endocrinology of fishes is essential for captive maturation and seed production in the field of aquaculture. Studying the spermatology of fishes is a comparatively new focus in aquaculture, which has emerged as an important area of fish research over the past two decades. In this regard, the cryopreservation of fish gametes is a crucial aspect. Moreover, energetics studies of gametes have become essential, considering the loss of vigour in the spermatozoa after cryopreservation.The latest development in this context is the cryopreservation of spermatogonial stem cell, which is also covered in the book, along with detailed information on embryo cryopreservation in fishes and crustaceans. The role of cryopreservation in conservation programmes is another important aspect, one that will especially interest biologists.This book addresses central issues in fish gamete cryopreservation and breeding, while also reviewing the history of cryopreservation. Its most unique feature is the breadth of its coverage, from basic information on reproduction in fishes, to such advanced topics as embryo cryopreservation. Chiefly intended as a handy troubleshooting guide, the book represents a valuable resource for research students in related fields.

Understanding the reproductive physiology and endocrinology of fishes is essential for captive maturation and seed production in the field of aquaculture. Studying the spermatology of fishes is a comparatively new focus in aquaculture, which has emerged as an important area of fish research over the past two decades. In this regard, the cryopreservation of fish gametes is a crucial aspect. Moreover, energetics studies of gametes have become essential, considering the loss of vigour in the spermatozoa after cryopreservation. The latest development in this context is the cryopreservation of spermatogonial stem cell, which is also covered in the book, along with detailed information on embryo cryopreservation in fishes and crustaceans. The role of cryopreservation in conservation programmes is another important aspect, one that will especially interest biologists. This book addresses central issues in fish gamete cryopreservation and breeding, while also reviewing the history of cryopreservation. Its most unique feature is the breadth of its coverage, from basic information on reproduction in fishes, to such advanced topics as embryo cryopreservation. Chiefly intended as a handy troubleshooting guide, the book represents a valuable resource for research students in related fields.

Numerous fishery researchers have attempted to preserve viable fish sperm, but only three investigations were successful in the fertilization of fresh eggs with frozen and thawed sperm: Blaxter (1953); Hoyle and Idler (1968); and Graybill and Horton (1969). Significant advances reported in this thesis were: the development of suitable life extenders for semen of steelhead trout (Salmo gairdneri), and coho (Oncorhynchus kisutch) and Chinook (0. tshawytscha) salmon; the selection of a life protector composed of 8.0% dimethyl. sulfoxide; the verification that the best rate of freezing semen was -30 C/mm, arid that the best method of thawing frozen sperm was in a 4 C water bath; and the determination that no equilibration time was necessary when fresh semen was diluted with extenders and protectors. Application of the above techniques led to the successful cryo-preservation of male gametes of steelhead trout and Chinook and coho salmon in liquid nitrogen ( -196 C). Frozen and thawed sperm was mixed with fresh eggs and resulted in maximum fertilizations of 59.1% for steelhead trout, 38.4% for spring Chinook salmon, and 79.2% for coho salmon. Details of the chemical constituents of the extenders and protectors tested are appended.

The large amount of information on fish reproduction available is not always readily accessible to all interested parties. Written to appeal to aquaculturalists, conservation managers, and scientific researchers, Methods in Reproductive Aquaculture provides an overview of available techniques and addresses ways to improve depleted stocks of endange

The successful reproduction of cultured brood stock is essential to the sustainable aquaculture of aquatic organisms. This book describes recent advances in the field of finfish reproductive biotechnology. The chapters in this volume are written by eminent scientists who review the progress and assess the status of biotechnology research that is applicable to the reproduction of finfish species for aquaculture. A wide range of topics is included starting with broodstock technologies such as broodstock genetics, broodstock nutrition, environmental control of maturation and impacts of stress on broodstock, gametes and progeny. The volume includes technologies for induction of ovulation and spermiation using synthetic hypothalamic peptides. Gamete technologies which are described include cryopreservation, chromosome set manipulation, disease prevention and control for gametes and embryos and the development of transgenic fish with enhanced production characteristics. Genetic and endocrine technologies for the production of monosex male and female fish stocks are also described. The closing chapter summarizes the discussion of each topic at the workshop, provides recommendations to industry and describes priorities of research and development. Researchers as well as teaching faculty in the aquaculture field will find this volume of great value.

"Cryopreservation is a powerful tool for the long term storage of genetic material from endangered species. While mammalian gametes have long been freezable, eggs and embryos from fish have yet to be successfully frozen. Furthermore, protocols for freezing fish sperm have low success rates. In an effort to overcome the limitations in gamete manipulation currently impeding successful fish gamete cryopreservation, I outline two experiment using zebrafish (Danio rerio) as a model for freshwater fish species. First, I attempted to extend working time in both eggs and sperm by incubating the gametes in rainbow trout oviductal fluid (RTOF), RTOF + HEPES, or RTOF under a blood-gas atmosphere. Incubation in RTOF under a blood gas atmosphere significantly extended viability in both gametes to 24 hours. Second, I attempted to minimize the number of sperm necessary to fertilize a single egg by reducing the volume in which the eggs were fertilized and by comparing the traditional fertilization system to a novel inverted drop technique. There were no differences between fertilization rates with sperm concentrations ranging from 1575 to 4 sperm/[micro]L . Furthermore, the inverted drop technique improved overall fertilization. Both increased gamete manipulation time and reduced sperm waste have the potential to improve cryopreservation success in fish gametes"--P. v.

While it is barely 50 years since the first reliable reports of the recovery of living cells frozen to cryogenic temperatures, there has been tremendous growth in the use of cryobiology in medicine, agriculture, horticulture, forestry, and the conservation of endangered or economically important species. As the first major text on cryobiolog