The Construction And Characteristics Of All-female Diploid And Triploid Crucian Carp

In many species of cultured finfish, females exhibit higher growth rates than males and attain larger sizes. In some species, males mature before reaching marketable size. These observations result in a larger dispersion of sizes and an overall reduction in production. Therefore, there is great interest from the private sector in the production of all-female stocks. Functional sex reversal male gynogenetic Japanese crucian carp (2n=100) were obtained by oral administration of 17-a-methyltestosterone at a dosage of 100ug/g diet for 60 days to gynogenetic Japanese crucian carp(Carassius cuvieri,2n=100). The fertile all-female diploid Japanese crucian carp (2n=100) and sterile all-female triploid hybrids (3n=150) were produced by fertilizing sperm of the sex reversal males with the haploid eggs of gynogenetic Japanese crucian carp and diploid eggs of allotetraploid hybrids (4n=200) of red crucian carp(Carassius auratus red var)(♀) x common carp(Cyprinus carpio)(♂), respectively. The all-female gynogenetic crucian carp line lays the foundation for the establishment of a genetically pure line of Japanese crucian carp. It is the first report of all-female triploid hybrids achieved by the combination of gynogenesis, sex reversal, and interspecific mating. These results prove that the sex determination type of female Japanese crucian carp is XX and female allotetraploid hybrid is XXXX. In addition, both the all-female gynogenetic crucian carp and all-female triploid crucian carp had fast growth rates, which will be of benefit in aquaculture. The combination of gynogenesis and sex reversal has great significance in fish genetic breeding.