抄録
As a biomarker for environmental estrogens in marine waters, concentrations of serum vitellogenin (VTG), estradiol-17β (E2) and testosterone (T) were investigated in wild flounder (Pleuronectes yokohamae) from September 1998 to January 2000 at Suou Nada and Hiroshima Bay in the Seto Inland Sea. In female fish, levels of serum VTG, E2 and T markedly increased according to the increase in the gonadosomatic index (GSI) at the period of maturity from November to February, and the level of serum VTG reached its maximum at GSI 15%. In addition, in male fish, levels of GSI, E2 and T increased from November to February; however, the level of serum VTG in male fish (60-1800 ng/ml) was almost constant throughout the year and was very low compared with that of mature female fish. The findings in this study suggest that the environmental estrogenic effect on wild flounder was weak or undetectable in the Seto Inland Sea.