Lycium barbarum polysaccharide (LBP) is one of the main active ingredients in the fruit of L. barbarum L. It has been used as herbal medicine for thousands of years in China. In this study, Nile tilapia (Oreochromis niloticus) was taken as the research object. After feeding tilapia with 5 different doses of LBP (0 mg/kg, 500 mg/kg, 1000 mg/kg, 1500 mg/kg, 2000 mg/kg) for 55 d, it was found that LBP could promote the growth of tilapia, and this effect was the strongest at Group 1500 mg/kg. Apoptosis analysis in the liver and spleen showed that dietary supplementation with 1000 mg/kg LBP had the best protective effect on the spleen and liver in tilapia. Combined transcriptomics and metabolomics of the spleen in tilapia at Group 0 mg/kg and 1000 mg/kg showed that the differentially expressed genes (DEGs) such as NT5C2L1, pmm1, FasL and the differentially metabolites such as xanthine, dGMP, guanine and glutamate were mainly concentrated in signaling pathways such as Purine metabolism and FoxO signaling pathway. In conclusion, LBP regulates the metabolic waste levels of tilapia mainly through Purine metabolism and the FoxO signaling pathway, thereby inhibiting cell apoptosis, improving the utilization of nutrients, and promoting the growth of tilapia. This study not only provides a theoretical basis for the application of LBP in aquatic animals but also provides useful information for the healthy development of the aquaculture.

This study was explored the supplementary of vitamin E on reproduction of tilapia. Five vitamin E supplements (0, 40, 80, 120 and 160 mg/kg) were tested for 90 days. Results: The SGR, GSI and ovarian maturity of female were the highest at Group 120 mg/kg, and the FCR was the lowest. The SGR, GSI and testis maturity of male were the highest at Group 160 mg/kg, and the FCR was the lowest. The levels of FSH and P were significantly increased at Group 120 mg/kg in female, and the levels of E2 reached the maximum. The levels of T and GnRH were increased at Group 160 mg/kg in male. The expression of FSHR in female liver was the highest at Group 160 mg/kg, and the expression of FSHR in ovary was the highest at Group 40 mg/kg. The expression of FSHR and pgr in female kidney was significantly increased at Group 40 and 80 mg/kg. The expression of FSHR and pgr in testis was the highest at Group 160 mg/kg. In conclusion, vitamin E can regulate the secretion levels of reproductive hormones and the expression levels of FSHR and pgr during different developmental stages in tilapia, and thus promote tilapia reproduction and growth. Among them, the reproductive and growth performance of female tilapia were the greatest at Group 120 mg/kg, and for male tilapia, these parameters were the greatest at Group160 mg/kg.