Bell Cameron, Raynal Rebecca S, Noble Daniel W A, Schwanz Lisa E, Warner Daniel A, Pruett Jenna E, Riley Julia L
Mount Allison University, Sackville, New Brunswick, Canada, E4L 1G7.
Evolution & Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052,Australia.
J Exp Biol. 2025 Feb 15;228(4). doi: 10.1242/jeb.249960. Epub 2025 Feb 21.
The embryonic environment is critical for the development of many ectothermic vertebrates, which makes them highly vulnerable to environmental change. Changes in temperature and moisture, in particular, are known to influence embryo survival and offspring phenotypes. Although most papers concerning phenotypic development of terrestrial ectotherms focus on the role of temperature on eggs and embryos, the comparatively small number of studies on the effects of substrate moisture are well suited for quantitative analysis aimed at guiding future research. To accomplish this goal, we compiled data from 37 studies on 28 different reptile species and used a meta-analytic approach to quantify the effect of substrate moisture on several offspring outcomes: hatching success (survival), incubation duration, hatchling mass and length, and sex ratio. We found that substrate moisture had a small effect across most traits but significantly affected body size (i.e. length and mass), with wetter conditions producing longer and heavier hatchlings. Temperature also moderated the effect of moisture on hatching success, with higher temperatures resulting in lower success. Additionally, the effect of moisture on hatching success and hatchling mass was enhanced by larger differences in moisture concentration between treatments, yet the effect was small. Lastly, substrate moisture affected sex ratio in turtles, but not in other squamates. Overall, these analyses provide a foundation for further research investigating the effects of moisture on oviparous reptile development. Increasing the diversity of environmental variables for which we understand their impact on animal phenotype will be beneficial in an era with wide-ranging global change.
胚胎环境对许多变温脊椎动物的发育至关重要，这使得它们极易受到环境变化的影响。特别是温度和湿度的变化，已知会影响胚胎存活和后代表型。尽管大多数关于陆生变温动物表型发育的论文都关注温度对卵和胚胎的作用，但相对较少的关于基质湿度影响的研究非常适合进行旨在指导未来研究的定量分析。为了实现这一目标，我们收集了来自对28种不同爬行动物的37项研究的数据，并采用荟萃分析方法来量化基质湿度对几种后代结果的影响：孵化成功率（存活率）、孵化持续时间、幼体质量和长度以及性别比例。我们发现，基质湿度对大多数性状的影响较小，但对体型（即长度和质量）有显著影响，湿度较高的条件会产生更长、更重的幼体。温度也调节了湿度对孵化成功率的影响，温度越高，成功率越低。此外，处理之间湿度浓度差异越大，湿度对孵化成功率和幼体质量的影响就越大，但影响较小。最后，基质湿度影响海龟的性别比例，但不影响其他有鳞目动物。总体而言，这些分析为进一步研究湿度对卵生爬行动物发育的影响提供了基础。在全球变化广泛的时代，增加我们了解其对动物表型影响的环境变量的多样性将是有益的。
