Data from: Maternal allocation of carotenoids increases tolerance to bacterial infection in brown trout

Life-history theory predicts that iteroparous females allocate their resources differently among different breeding seasons depending on their residual reproductive value. In iteroparous salmonids there is typically much variation in egg size, egg number, and in the compounds that females allocate to their clutch. These compounds include various carotenoids whose functions are not sufficiently understood yet. We sampled 37 female and 35 male brown trout from natural streams, collected their gametes for in vitro fertilizations, experimentally produced 185 families in 7 full-factorial breeding blocks, raised the developing embryos singly (n = 2960), and either sham-treated or infected them with Pseudomonas fluorescens. We used female redness (as a measure of carotenoids stored in the skin) and their allocation of carotenoids to clutches to infer maternal strategies. Astaxanthin contents largely determined egg colour. Neither egg weight nor female size was correlated with the content of this carotenoid. However, astaxanthin content was positively correlated with larval growth and with tolerance against P. fluorescens. There was a negative correlation between female skin redness and the carotenoid content of their eggs. Although higher astaxanthin contents in the eggs were associated with an improvement of early fitness-related traits, some females appeared not to maximally support their current offspring as revealed by the negative correlation between female red skin colouration and egg carotenoid content. This correlation was not explained by female size and supports the prediction of a maternal trade-off between current and future reproduction.

生活史理论（Life-history theory）预测，多次繁殖的雌性个体的资源分配策略会因剩余繁殖价值的差异，在不同繁殖季呈现不同模式。在鲑科（salmonids）鱼类中，卵大小、卵数量以及雌性分配至卵块的化合物组成通常存在显著变异，其中包含多种功能尚未被充分阐明的类胡萝卜素（carotenoids）。我们从自然溪流中采集了37条雌性与35条雄性褐鳟，收集其配子（gametes）用于体外受精（in vitro fertilizations），通过7个全因子繁殖区块实验构建了185个家系，将发育中的胚胎单独饲养（总样本量n=2960），并分别进行假处理或荧光假单胞菌（Pseudomonas fluorescens）感染处理。我们以雌性皮肤红度作为皮肤储存类胡萝卜素的衡量指标，并结合其向卵块分配的类胡萝卜素水平，推断其母性繁殖策略。虾青素（astaxanthin）含量是决定卵色的核心因素。卵重与雌性体型均与该类胡萝卜素含量无显著相关性。然而，虾青素含量与幼体生长速率及抗荧光假单胞菌感染能力呈正相关。雌性皮肤红度与其卵块的类胡萝卜素含量呈负相关。尽管卵内更高的虾青素含量与早期适合度相关性状的改善存在关联，但部分雌性并未最大化投入当前繁殖后代——这一现象可通过雌性皮肤红度与卵类胡萝卜素含量的负相关关系得以体现。该相关性不受雌性体型的影响，支持了"母体会在当前繁殖与未来繁殖之间存在权衡"的理论预测。