The viviparous teleost Redtail Splitfin (Xenotoca eiseni) is a live bearing fish that presents a novel freshwater model for investigating the effects of maternally derived micropollutants on vulnerable early developmental life stages. Here, adult female X. eiseni were exposed to 17α-ethinyloestradiol (EE2), a potent contraceptive oestrogen, at environmentally relevant concentrations, to investigate for effects on sex partitioning and development. Pregnant and non-pregnant females were exposed for four weeks to EE2 at measured concentrations of 0.9 and 3.4 ng/L EE2 and offspring from gravid females were kept in clean water for a further four weeks. Only pregnant females were seen to respond to 3.4 ng/L EE2 with an increase in the transcription of hepatic vitellogenins (vtgA, vtgB and vtgC). Offspring of exposed mothers showed no obvious effects on somatic growth, gonadal development, sex partitioning or development. However, there was a higher rate of deformities and developmental abnormalities in offspring of EE2-exposed females. The work presented provides the foundation for the development of X. eiseni as a new freshwater model for studies on maternal transfer of chemical pollutants in live bearing animals.

胎生硬骨鱼Redtail Splitfin（Xenotoca eiseni）是一种活鱼，提供了一种新颖的淡水模型，用于研究母体来源的微污染物对脆弱的早期发育阶段的影响。在这里，成年雌性X. eiseni被暴露于与环境有关的有效浓度的17α-乙炔雌二醇（EE2），一种有效的避孕雌激素，以研究其对性别分配和发育的影响。怀孕和未怀孕的雌性分别以0.9和3.4 ng / L EE2的浓度暴露于EE2四周，而妊娠雌性的后代则在清水中再饲养四周。仅观察到怀孕的女性对3.4 ng / L EE2的反应与肝卵黄蛋白原的转录增加有关（vtgA，vtgB和vtgC）。暴露母亲的后代对体细胞生长，性腺发育，性别分配或发育没有明显影响。但是，暴露于EE2的雌性的后代中畸形和发育异常的发生率更高。提出的工作为埃森氏疟原虫的开发奠定了基础，后者是一种新的淡水模型，用于研究母体活体动物中化学污染物的母体转移。