LAUSR

Abstract The yellow drum (Nibea albiflora) is one of the most important species for commercial fisheries and a promising candidate for aquaculture in China. This fish exhibits significant sexually dimorphic growth and the efficiency and profitability of its aquaculture could be maximized by all-female production. Consequently, we developed an effective protocol to induce meiotic gynogenesis using heterologous sperm and defined the sex determination system in yellow drum. Spermatozoa from the rock bream (Oplegnathus fasciatus) were used, and the optimal UV-irradiation dose for genetically inactivating the spermatozoa was determined to be 45 mJ/cm2. Cold-shock temperature, duration and time of initiation were optimized, and the best yield of gynogens was obtained with a cold-shock at 4 °C for a period of 8 min, initiated 2 min after fertilization. The DNA ploidy test by flow cytometry showed that the gynogenetic larvae were diploids. The analysis of microsatellite loci revealed an exclusive maternal inheritance in all the gynogens tested, further confirming the success of the diploid gynogenesis using the protocol that we established. All the juvenile gynogens examined by histology were female, supporting the assumption of female homogametic sex determination in the yellow drum. In conclusion, we have developed an effective and reliable method to induce meiotic gynogenesis of yellow drum. Our approach could be potentially applied to produce monosex yellow drum on a large scale to meet the demands of the aquaculture industry.