Data from: An androgenic endocrine disruptor alters male mating behaviour in the guppy (Poecilia reticulata)

Hormonally active chemical pollution threatens human and wildlife populations globally. However, despite the well-established capacity of endocrine-disrupting chemicals (EDCs) to alter reproductive traits, relatively few studies have examined the impacts of EDCs on mechanisms of sexual selection. This study investigated the effects of short-term exposure to an environmentally realistic level of 17β-trenbolone—a potent anabolic steroid used in livestock production worldwide—on male mate preference, reproductive behaviour and morphology in the guppy (Poecilia reticulata). Male guppies prefer to mate with larger females because such females are generally more fecund. Hence, males gain direct fitness benefits by being choosy. Here, we found no significant effect of 17β-trenbolone exposure on male courting behaviour, with both unexposed and exposed males courting larger females more often. However, exposure to 17β-trenbolone significantly altered the amount of coercive copulatory behaviour (‘sneak’ matings) performed. Specifically, while both unexposed and exposed males demonstrated a preference for larger females by conducting more sneaking attempts towards these females, exposed males carried out a greater number of sneaks towards large females than did unexposed males. Further, exposure resulted in increased male condition index (i.e., mass relative to length). Together, our results show for the first time that 17β-trenbolone can alter reproductive behaviour and morphology in male fish at concentrations as low as 4 ng/L, highlighting the potential for disruption of reproductive processes in wildlife exposed to this potent agricultural contaminant.

Usage Notes
Bertram 2018 - Behav Ecol

全球范围内，具有激素活性的化学污染物正威胁着人类与野生生物种群的存续。尽管内分泌干扰物（endocrine-disrupting chemicals, EDCs）改变生殖性状的能力已被广泛证实，但针对EDCs对性选择机制影响的研究仍相对匮乏。本研究以孔雀鱼（Poecilia reticulata）为研究对象，探究了短期暴露于环境相关浓度的17β-群勃龙（一种全球范围内广泛用于畜禽生产的强效合成代谢类固醇）对雄性配偶偏好、生殖行为与形态特征的影响。雄性孔雀鱼更倾向于与体型更大的雌性交配，因为这类雌性通常具有更高的繁殖力，因此雄性通过择偶可获得直接的适合度收益。本研究结果显示，17β-群勃龙暴露对雄性求偶行为无显著影响：未暴露组与暴露组雄性均更频繁地向体型更大的雌性开展求偶行为。但17β-群勃龙暴露显著改变了强制交配行为（即“偷袭”交配）的发生频次。具体而言，尽管未暴露组与暴露组雄性均通过对大型雌性发起更多偷袭尝试来表现出择偶偏好，但暴露组雄性针对大型雌性的偷袭次数显著多于未暴露组雄性。此外，暴露处理使雄性的身体状况指数（即体重相对体长的比值）显著升高。综上，本研究首次证实，在低至4 ng/L的浓度下，17β-群勃龙即可改变雄性鱼类的生殖行为与形态特征，凸显了这种强效农业污染物对暴露野生生物生殖过程的潜在干扰风险。使用说明：Bertram 2018，发表于《行为生态学》（Behav Ecol）