Tetraploidy in aquatics; reasons, induction and identification methods and physiological effects

Nowadays, chromosome manipulation of different aquatics is a useful method in improving their genetic characteristics. Tetraploids have four sets of chromosomes in each cell. Tetraploids are one of the most effective methods for producing broodstocks which can be used in androgenesis, gynogenesis as well as is an economical way to produce non-induced triploid populations. Induction of tetraploidy in aquatics are usually done by late physical or chemical shocks, after fertilization and before the first mitotic division of the egg, cleavage. These aquatics are able to produce diploid gametes that can be used to achieve higher levels of ploidy. Survival, growth, and other physiological parameters in tetraploid are different from diploid ones. The percentage of tetraploid induction varies in different individuals and is affected by environmental and shock conditions as well as genetic characteristics. In this article, we will review the mechanism of tetraploid induction, methods of production, application, detection of ploidy levels and performance of tetraploids.