Data from: Water restriction causes an intergenerational trade-off and delayed mother-offspring conflict in a viviparous lizard

1. Parenting is costly and because the relationship between the mother and embryos is not mutualistic, mother-offspring conflicts may exist whenever resource are scarce. However, intergenerational trade-offs and conflicts resulting from limited access to water, a vital and depreciable resource, remain largely overlooked. 2. In this study, we examined the physiological, reproductive and life history responses to water restriction in the European Common Lizard (Zootoca vivipara). We hypothesised that, under water-limited conditions, pregnant females experience both short-term and long-term physiological impacts (dehydration and stress) underlying an allocation trade-off for water between mothers and offspring. 3. Water restriction led to a decrease in body mass, and an increase in plasma osmolality (dehydration) and corticosterone concentration in both males and females. The extent of the dehydration was positively correlated with fecundity in females. This suggests a trade-off between maternal water balance and allocation of water to developing embryos during reproduction. 4. Water restriction had no immediate effect on reproductive output or offspring morphology at birth. Yet, water restriction in pregnant females enhanced their reproductive effort the following year but reduced the early life growth and annual survival of their second-year offspring. 5. These delayed fitness responses to water restriction in offspring and mothers suggest that water can trigger intergenerational conflicts as demonstrated for energy. Although the mediation of this conflict remains to be clarified, we hypothesized that it represents a selective force that influences reproductive strategies.1. 亲代投入代价高昂，且由于母体与胚胎间的关系并非互利共生，当资源匮乏时，母子间可能存在冲突。然而，由获取受限的关键可耗竭资源——水——所引发的代际权衡与冲突，在很大程度上仍未得到充分关注。 2. 本研究以欧洲普通蜥蜴（Zootoca vivipara）为研究对象，探究了其在水分限制条件下的生理、生殖以及生活史响应。我们提出假说：在水分受限的环境中，妊娠雌性个体将面临短期与长期的生理影响（脱水与应激），而这种影响背后存在母体与胚胎间的水分分配权衡。 3. 水分限制会导致雌雄个体的体重下降，同时使其血浆渗透压（脱水指标）与皮质酮浓度升高。雌性个体的脱水程度与繁殖力呈正相关，这表明在繁殖过程中，母体的水分平衡与向发育中胚胎分配水分之间存在权衡。 4. 水分限制对雌性的繁殖输出以及初生幼体的形态并无即时影响。然而，妊娠雌性在经历水分限制后，次年的繁殖投入会有所提升，但其子代的早期生长与二龄幼体的年度存活率则会下降。 5. 上述子代与母体在水分限制下产生的延迟适合度响应表明，与能量因素类似，水分也可引发代际冲突。尽管该冲突的调控机制仍有待阐明，但我们提出假说：这一代际冲突是影响生殖策略的选择压力之一。