Great concern has been raised over the potential impact of environmental contaminants on fish populations that inhabit the Three Gorge Reservoir. The present study investigated the endocrine-disrupting effects of di-(2-ethylhexyl)-phthalate (DEHP) on the Chinese rare minnow (Gobiocypris rarus), an endemic fish distributed in upstream waters in the Yangtze River. Adult rare minnow were exposed to environmentally relevant concentrations of DEHP (0 mg/L, 3.6 mg/L, 12.8 mg/L, 39.4 mg/L, and 117.6 mg/L) for a 21-d period. Then, concentrations of sex hormones in the plasma and relative transcription of various associated genes were measured in the hypothalamic-pituitary-gonadal (HPG) axis and liver of the fish. Exposure to DEHP resulted in greater circulating concentrations of testosterone (T) and lower concentrations of estradiol (E2), which were accompanied by upregulation of Cyp17 mRNA and downregulation of Cyp19a mRNA in the gonads of females. In males, increases of T and E2 levels were consistent with upregulation of Cyp17 and Cyp19a in the gonads. Furthermore, the T/E2 ratio was increased in females but reduced in males. A significant increase in the levels of hepatic vitellogenin (VTG) gene transcription was observed in both females and males. The present study showed that waterborne exposure to DEHP altered plasma sex hormone levels and modulated gene transcription profiles of associated genes in the HPG axis and liver, occurring mostly at higher concentrations (>39.4 mg/L), which suggests that environmental concentration of DEHP (5.4 mg/L) alone might not disturb the endocrine system of the rare minnow in the TGR.

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The supply of a balanced portion of nutrition is vital for the success of the restocking program of the Yangtze sturgeon, an endangered sturgeon in the Yangtze River, however, knowledge of the nutritional requirement of this endangered species is scarce. The present study was performed to investigate the optimum dietary lipid requirement of the Yangtze sturgeon juveniles (initial weight, 184.24 ± 6.79 g). Five isonitrogenous diets containing a mixture of fish oil and soybean oil (1:1 ratio) at five different levels (35, 63, 90, 124 and 168 g/kg) were prepared and each prescribed diet was hand‐fed to triplicate groups of fish for 50 days. Results showed that feed intake of fish was not affected, but growth and feed utilization rate increased and then declined with the increment of dietary lipid content. Similar trends were observed for the activities of enzymes involved in lipid digestion and metabolism. The lipid content of fish dorsal muscle and liver together with serum triglyceride content was linearly elevated with increasing inclusion of dietary lipid. The inclusion of 12.4% dietary lipid significantly reduced the content of deamination product ammonia in serum. Excessive lipid intake caused noticeable hepatocellular vacuolation as shown by histological staining. Based on the regression analysis between growth response and dietary lipid levels, the optimum dietary lipid level of juvenile Yangtze sturgeon was estimated to be 141.67 g/kg diet.

In recent years, the rapid development of financial technology (fintech) has greatly impacted the traditional banking industry, posing both challenges and opportunities for banks. In this study, we investigate the influence of fintech on the net interest margin and non-performing loan ratio of banks in China.To measure the level of fintech development in banks, we construct a Bank Fintech Development Index (BFDI) based on text analysis of annual reports. We then use a panel data regression model to analyze the impact of fintech development on the net interest margin and non-performing loan ratio of banks, controlling for other factors such as bank size, capital adequacy, and macroeconomic conditions.Our empirical results show that the development of fintech has a significant positive impact on the net interest margin of banks, indicating that banks that have adopted fintech are able to generate higher profits from their interest-bearing assets. We also find that the development of fintech has a significant negative impact on the non-performing loan ratio of banks, suggesting that fintech can help banks improve their risk management and reduce their credit losses.Therefore, banks should continue to embrace fintech and invest in new technologies to remain competitive in the rapidly evolving financial landscape.