Abstract:Endocrine disruptors (EDs) are a structurally diverse group of compounds that may adversely affect the health of humans, wildlife and fisheries, or their progeny by interaction with the endocrine system. Many EDs have been detected in aquatic environments, many of which are capable of disrupting endocrine functions of a variety of aquatic invertebrates. In the present study, the estrogenic compound Fenvalerate and androgenic compound TBTC were screened for their effect on the batch carrying eggs every parental rotifer (P),total numbers of eggs, offspring production, and mictic female production of the freshwater rotifer Brachionus calyciflorus. Treatment with Fenvalerate at concentrations (except 3.2μg/L) significantly increased the frequency of carrying 3 eggs (p<0.05).Treatments with Fenvalerate at concentrations of 32μg/L to 2000μg/L significantly increased the total number of eggs production compared to controls (p<0.05). Treatment with TBTC at 0.0016,0.04, 0.2 and 1μg/L resulted in a significantly higher frequency of females carrying 3 and 4 eggs compared to control (p<0.05), but the frequency of carrying 1 egg was lower than control. The total number of eggs and offspring were all significantly lower than control (0.0016μg/L excluded) (p<0.05). Moreover, the ratios of mictic female (MF%) of parents and the first generation (F1) were also affected by Fenvalerate and TBTC. MF% of parents and F1 was significantly lower than control only in the two lowest concentrations of Fenvalerate at 0.64μg/L and 32μg/L (p<0.01), but there was no difference between treatments and control in higher concentrations, and no effect on MF/AF (mictic females/amictic females) of the F1 as well. The concentrations of TBTC only over 5μg/L significantly affected the MF% of parental compared to control (p<0.01), but MF% of F1 was obviously affected at all concentrations except 02μg/L. The MF/AF of parents and F1 were quite similar. TBTC had a negative effect on total number of eggs and offspring, whereas Fenvalerate increased them. Consequently, we can conclude that Fenvalerate and TBTC significantly affect the reproduction of rotifers through mechanisms that are not well understood.