Atomic genetic strategy in fisheries is to use acquired, distinct and stable markers to distinguish genotypes among fish populations or species. This strategies can provide data on the level of genetic variability and circulation based on mating design, life history, stock size, movement and climate. This volume mentions several atomic devices and strategies that have been used on fisheries to solve different problems for research, and improve the fish production. It is very important to research about the molecular genetics in fisheries, to the production continues to growth. Also, several strategies that have been used in aquaculture production chain are already showing the importance of genetic knowledge to improve the yield in a sustainable manner. This volume summarizes the progress and some applications of molecular technology in a wide range of options in fisheries.