Biotechnology and fish culture

Biotechnology can currently be considered of importance in aquaculture. The increase in the production of aquatic organisms over the last two decades through the use of biotechnology indicates that in a few generations biotec hnology may overtake conventional techniques, at least for the commercially more valuable species. In the last few years, genetics has contributed gre atly to fish culture through the application of the more recent techniques developed in biotechnology and in genetic engineering. At present, the most commonly used methods in fish biotechnology are chromosome manipulation an d hormonal treatments, which can be used to produce triploid, tetraploid, h aploid, gynogenetic and androgenetic fish. These result in the production o f individuals and lineages of sterile, monosex or highly endogamic fish. Th e use of such strategies in fish culture has as a practical objective the c ontrol of precocious sexual maturation in certain species; other uses are t he production of larger specimens by control of the reproductive process an d the attainment of monosex lines containing only those individuals of grea ter commercial value. The use of new technologies, such as those involved i n gene transfer in many species, can result in modified individuals of grea t interest to aquaculturists and play important roles in specific programme s of fish production in the near future.