First evidence of WW superfemale for hybrid sturgeon, the bester (Huso huso × Acipenser ruthenus)

Sex control offers a promising strategy for cost-effective aquaculture in certain fish species. Sturgeons, which utilize the ZZ/ZW sex determination system, are particularly valuable for producing high-priced black caviar derived from female roes, making all-female production highly desirable. However, this goal has yet to be fully realized. In this study, we identified a short genomic region specific to the Z and W genomic scaffolds of Acipenser ruthenus and developed a polymerase chain reaction (PCR) method to distinguish between the Z and W alleles. Using PCR, 1280 A. ruthenus , 66 A. baerii baerii , and 31 F2 hybrids of besters ( Huso huso × A. ruthenus ) were genotyped, revealing either a single Z amplicon or dual Z plus W amplicons in an approximately 1:1 ratio. This indicates successful discrimination of the ZZ/ZW genotypes. Additionally, gonadal sex was identified in 145 of the genotyped individuals, all of which corresponded to their genetic sex. Gynogenetic individuals of the F3 bester hybrid were also genotyped, with 25 of 112 (22.3 %) exhibiting only W amplicons, identifying them as WW superfemales. These findings contribute to the advancement of all-female sturgeon production for aquaculture, facilitating the efficient farming of these highly prized species. • Developed a PCR method to distinguish Z and W sex chromosomes in sturgeons. • Determined genetic sex in three aquacultured sturgeon species using PCR. • Identified WW superfemales by genotyping gynogens from bester hybrids.