Orton Frances, Baynes Alice, Clare Frances, Duffus Amanda L J, Larroze Severine, Scholze Martin, Garner Trenton W J
Biosciences, School of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK,
Ecotoxicology. 2014 Sep;23(7):1359-65. doi: 10.1007/s10646-014-1261-3. Epub 2014 Jun 17.
Amphibians are declining and fertility/fecundity are major drivers of population stability. The development of non-destructive methods to assess reproductive health are needed as destructive measures are fundamentally at odds with conservation goals for declining species. We investigated the utility of body size, nuptial pad size and forelimb width as non-destructive biomarkers of internal reproductive physiology, by analysing correlations with commonly used destructive methods in adult male toads (Bufo bufo) from a low human impact and a high human impact site. Principal component analyses revealed that size was the most important variable for explaining inter-individual differences in other measured endpoints, both non-destructive and destructive, except for hormone levels and nuptial pad, which were independent of size. Toads from the LI and the HI site differed in almost all of the measured endpoints; this was largely driven by the significantly smaller size of toads from the HI site. Correlational analyses within sites revealed that size was correlated with several reproductive endpoints in toads from the HI site but not the LI site, indicating a possible limiting effect of size on reproductive physiology. Intersex was observed in 33% of toads from the HI site and incidence was not related to any other measured endpoint. In conclusion, we provide evidence that size is associated with reproductive physiology and that nuptial pad/hormone levels have potential as additional markers due to their independence from size. We also show that human activities can have a negative effect on reproductive physiology of the common toad.
两栖动物数量正在减少，而繁殖力/生殖力是种群稳定的主要驱动因素。由于破坏性措施与濒危物种的保护目标根本相悖，因此需要开发非破坏性方法来评估生殖健康。我们通过分析来自低人类影响和高人类影响地点的成年雄性蟾蜍（Bufo bufo）中，身体大小、婚垫大小和前肢宽度与常用破坏性方法之间的相关性，研究了它们作为内部生殖生理非破坏性生物标志物的效用。主成分分析表明，除了与大小无关的激素水平和婚垫外，大小是解释个体间在其他测量终点（包括非破坏性和破坏性终点）差异的最重要变量。来自低影响和高影响地点的蟾蜍在几乎所有测量终点上都存在差异；这在很大程度上是由高影响地点蟾蜍明显较小的体型驱动的。各地点内的相关性分析表明，大小与高影响地点蟾蜍的几个生殖终点相关，但与低影响地点的蟾蜍无关，这表明大小可能对生殖生理有限制作用。在高影响地点33%的蟾蜍中观察到了雌雄同体现象，其发生率与任何其他测量终点均无关。总之，我们提供的证据表明，大小与生殖生理相关，婚垫/激素水平因其与大小无关而有潜力作为额外的标志物。我们还表明，人类活动会对普通蟾蜍的生殖生理产生负面影响。
