This book looks at a broad spectrum of biotech research efforts and their applications to the fisheries and aquaculture industry. It looks at the application of genetic, cellular, and molecular technologies to enable fish farmers to produce a more abundant, resilient, and healthier supply of seafood. It cover topics ranging from brood stock improvement to fish health and gene transfer. This book will be a valuable tool to researchers, producers, and students interested in better understanding the field of fish biotechnology. Demand for fish is soaring worldwide. It appears unlikely that the increasing demand can be met through increased natural harvest. There is international recognition that many of natural ocean and freshwater fisheries are being harvested to their limit. Aquaculture could help to meet increasing demand, and biotechnology can make a great contribution to improve aquaculture yields. Aquaculture animals are particularly well suited for research in biotechnology. Experimentation is facilitated by the availability of large numbers of gametes, use of external fertilization, and ease of in vitro rearing of embryos. In addition, many aquatic animals can be treated with hormones during development to induce sterility or functional sex reversal thus simplifying experimental procedures. The agenda for modern biotechnology in aquaculture seems very similar to that of livestock and agriculture. Remarkable achievements have been made in the recent past in increasing production of crops, livestock and poultry through genetic and bio-technological tools. The potential areas of biotechnology in aquaculture include the use of synthetic hormones in induced breeding, production of monosex, uniparental and polyploid population, molecular biology, transgenic fish, gene banking, improved feeds and health management and development of natural products from marine organisms.