School of Biological Sciences, Monash University, Victoria, Australia.
School of Biological Sciences, Monash University, Victoria, Australia.
Aquat Toxicol. 2019 Mar;208:118-125. doi: 10.1016/j.aquatox.2019.01.006. Epub 2019 Jan 9.
Among the handful of studies on the behavioural effects of endocrine disrupting chemicals (EDCs), only a few have set out to disentangle the mechanisms underpinning behavioural changes. In fish, previous studies have shown that both visual and chemical cues play an important role in mate choice. As such, contaminant-induced changes in either transmission or perception of mate choice cues could have direct implications for individual's fitness. One widespread contaminant of environmental concern is 17α-ethinyl estradiol (EE2), a synthetic estrogen used in the contraceptive pill. Here, we investigated the impacts of EE2 exposure (28 days; measured concentration 14 ng/L) on visual and chemical communication in wild guppies (Poecilia reticulata). Using a standard dichotomous mate choice assay, we first gave individual males (either control or EE2-exposed) the opportunity to court two size-matched females (one control and one EE2-exposed) using only visual cues. We then introduced chemical cues of females (control and EE2-exposed) to the trial tank. We found that there was no significant effect of EE2-treatment on total time males spent associating with the females, when given only visual cues. There was, however, a significant effect on male courtship behaviour, with both control and EE2-exposed males spending more time performing 'sigmoid' displays towards the visual cues of control females compared to EE2-exposed females. When males were presented with both visual and chemical female cues simultaneously, we found that males spent more time courting control females that were paired with EE2-chemical cues. Not only does our study uncover a previously unknown behavioural impact of EE2-exposure on chemical cues, but demonstrates that EE2-exposure can exert complex effects on visual and chemical communication in a mate choice context. Finally, we contribute to the discussion of intraspecific variability by providing data on the potential trade-offs underpinning contaminant-induced behavioural changes.
在少数关于内分泌干扰化学物质（EDCs）行为影响的研究中，只有少数研究旨在厘清行为变化的潜在机制。在鱼类中，先前的研究表明，视觉和化学线索在配偶选择中都起着重要作用。因此，配偶选择线索的传递或感知的污染物诱导变化可能会直接影响个体的适应度。一种广泛存在的环境污染物是 17α-乙炔雌二醇（EE2），一种用于避孕药的合成雌激素。在这里，我们研究了 EE2 暴露（28 天；测量浓度 14ng/L）对野生孔雀鱼（Poecilia reticulata）视觉和化学通讯的影响。使用标准的二分配偶选择试验，我们首先让个体雄性（对照或 EE2 暴露）仅使用视觉线索与两个大小匹配的雌性（一个对照和一个 EE2 暴露）求偶。然后，我们将雌性的化学线索引入试验水箱。我们发现，仅使用视觉线索时，EE2 处理对雄性与雌性的总关联时间没有显著影响。然而，对雄性求偶行为有显著影响，与 EE2 暴露的雌性相比，对照和 EE2 暴露的雄性对对照雌性的视觉线索表现出更多的“正弦”展示。当雄性同时呈现视觉和化学雌性线索时，我们发现雄性与配对 EE2 化学线索的对照雌性求偶时间更长。我们的研究不仅揭示了 EE2 暴露对化学线索的先前未知的行为影响，而且证明了 EE2 暴露可以在配偶选择情境中对视觉和化学通讯产生复杂的影响。最后，我们通过提供有关潜在权衡的潜在权衡的数据，为讨论种内变异性做出了贡献，这些权衡是污染物诱导的行为变化的基础。
