Faculty of Fisheries and Protection of Waters, South Bohemian Research Centre of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in České Budějovice, Zátiší 728/II, 389 25, Vodňany, Czech Republic.
Faculty of Fisheries and Protection of Waters, South Bohemian Research Centre of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in České Budějovice, Zátiší 728/II, 389 25, Vodňany, Czech Republic.
Sci Total Environ. 2019 May 1;663:206-215. doi: 10.1016/j.scitotenv.2019.01.276. Epub 2019 Jan 24.
High rates of progestins consumption in the form of active ingredients in women's oral contraceptives and other hormonal preparations may lead to their increased concentrations in aquatic environments and subsequent harmful effect on fish reproduction. The objective of the present study was to assess the effect of etonogestrel, a third-generation synthetic progestin, on the reproductive behavior, fertility, gonads histology, and secondary sexual characteristics of male and female Endler's guppies (Poecilia wingei). Fish were subjected for 34 days to two concentrations of etonogestrel, including one possibly environmentally relevant (3.2 ng L) and one sublethal (320 ng L) concentration. A mating behavior study was subsequently conducted and revealed that the treatment with etonogestrel significantly reduced mating frequency in the exposed fish compared to controls. All the exposed females were unable to reproduce. In addition, female fish exposed to the highest level of etonogestrel were masculinized, as their anal fins and body coloration showed patterns similar to those of male fish. Etonogestrel-exposed females also had fewer developed oocytes. In conclusion, the low etonogestrel concentration (3.2 ng L) led to a reduction of mating activity in males without effect on their reproductive success, but it completely inhibited reproduction in females. Exposure to etonogestrel clearly has more severe consequences for females than males.
高剂量孕激素以活性成分的形式存在于女性口服避孕药和其他激素制剂中，可能导致其在水生环境中的浓度增加，并对鱼类繁殖产生有害影响。本研究的目的是评估第三代合成孕激素依托孕烯对雄性和雌性恩氏丽鱼（Poecilia wingei）生殖行为、生育能力、性腺组织学和第二性征的影响。研究将鱼暴露于两种依托孕烯浓度中 34 天，包括一种可能具有环境相关性的（3.2ng/L）和一种亚致死浓度（320ng/L）。随后进行了交配行为研究，结果表明，与对照组相比，暴露于依托孕烯的鱼交配频率显著降低。所有暴露于依托孕烯的雌鱼都无法繁殖。此外，暴露于最高水平依托孕烯的雌鱼出现了雄性化，因为它们的臀鳍和体色呈现出与雄鱼相似的模式。暴露于依托孕烯的雌鱼卵母细胞也较少。总之，低浓度的依托孕烯（3.2ng/L）导致雄鱼交配活动减少，但对其繁殖成功率没有影响，而雌鱼则完全无法繁殖。依托孕烯暴露对雌性的影响显然比雄性更严重。
