Intergenerational Interference Effects Of Four Typical Environmental Hormones On Moina Macrocopa

To explore the disruptive effects of four typical environmental hormones, nonylphenol(NP), Bisphenol A(BPA),Estradiol(E2), Dibutyl phthalate(DBP) on Moina macrocopa through intergenerations, three consecutive generations(F0, F1, F2) of this species were exposed to different concentrations of environmental hormones in laboratory, and adult mortality, first reproductive time, neonate number, adult molting frequency, final body length were measured after a 15-d toxicity test. Furthermore, the intrinsic population growth rate(r) was calculated. The results showed that all four environmental hormones caused certain mortality in F0 animals. When treated with identical concentrations, the mortality of offspring generations increased with growing generations and the lethal effect was magnified compared to their mother generations. The reproductive abilities of three successive generation animals were remarkably inhibited(P < 0.05) in NP and DBP treatments, and the reproductive inhibition in offspring generation were higher than parental generations. BPA and E2 showed no significant inhibition on fecundity of the tested animals. First reproductive time was significantly postponed in F0 animals except for BPA treatment and the retardation was positively related to tested chemical concentrations, indicating a dose-effect relationship; the delay trend in first reproductive time also existed in both F1 and F2 generations and exhibited a lengthening effect. However, there was little effect on adult molting frequencies for all tested chemicals in three successive generations. Final body length of F0 and F1 animals treated with NP and DBP declined remarkably, showing a clear dose-effect relationship, but body length of F2 animals showed an increasing trend compared to mother generation for all treatments. NP and DBP significantly inhibited r value of tested animals and inhibition effect magnified the following generations. Intrinsic population growth rate was significantly hindered in F2 animals of BPA treatment, while E2 showed no adverse effect on r of all treatments.