The aim is to give basic informations on genetics and selective breeding of commercially important fish species in the Czech Republic, including conservation of original fish breeds. Particular goals are as follows: 1) To give information on domestication of main commercially important species, on the origin and development of breeds. 2) To explain breeding programs in aquaculture - crossbreeding, interspecific hybridization, selection, genome manipulations. 3) To explain in deeper consequences the regularities of qualitative and quantitative genetics of fish, chromosomal sex determination, reproductive and performance traits, as well as performance and heredity testing. 4) To characterize the genetic structure of populations and goals of conservation genetics. 5) To inform the students on the Animal Breeding Act and its decrees, on farmers´duties and on the state subvention policy in fish breeding and in the National programme for conservation and utilization of genetic resources for agriculture and nutrition.