Abstract:To evaluate the advantages of nucleus implantation in spring and autumn and their relationship with key environmental factors, production indicators and marine environmental factors across four production cycles from April 2020 to July 2022 were analyzed. Spring (S) and autumn (F) nucleus implantation groups were established, with implantation conducted in April 2020 (S20), April 2021 (S21), October 2020 (F20), and October 2021 (F21). The monthly survival rates of the cultured pearl oysters were monitored, and key environmental factors such as water temperature, dissolved oxygen, and salinity were measured. Pearls were harvested after 9 m of cultivation, and production indicators, including the retention rate, high-quality pearl rate, and pearl layer thickness, were recorded. Water temperature fluctuated seasonally from 17.23–33.23 ℃. The S groups (S20 and S21) and F groups (F20 and F21) experienced temperatures above or near 30 ℃ for five and two months, respectively. Dissolved oxygen levels varied from 4.44–8.08 mg/L with seasonal changes. Except for October, when salinity was relatively low, salinity remained stable between 30‰–35‰ in other months. The pH was stable and fluctuated between 8.05 and 8.28. The water transparency was 80–200 cm and was generally lower in summer and autumn and higher in winter and spring. At the end of the cultivation period, the survival rates were the highest in F21, followed by F20, S21, and S20, with the group F being better than the group S (P<0.05). In the group S, water temperature showed a strong negative correlation with stage-specific survival rates (P<0.05), whereas no correlations were found between survival rates and other environmental factors (P>0.05). In group F, no correlation was observed between the environmental factors and survival rates (P>0.05). The retention, commercial pearl, and high-quality pearl rates among the groups were similar (P>0.05), but the pearl layer thickness in the group S was greater than that in the group F (P<0.05), with an increase of approximately 20%. Nucleus implantation in autumn substantially improved the survival rate of the transplanted pearl oysters and increased pearl production, whereas the pearls produced by nucleus implantation in spring were of a better quality. In group S, the elevated mortality rate during summer was primarily attributed to high temperatures. This study provides valuable data and theoretical insights for healthy cultivation of seawater pearls.