In most animal taxa, large mothers (or those with high nutritional status) produce large offspring, leading to a maternal size-offspring size correlation, that is, a positive correlation between maternal size and offspring size. Here, we used the natural variation in maternal size between three natural populations of Buccinanops deformis (a marine snail with direct development, nurse egg feeding, and a single embryo per egg capsule) to study maternal investment and offspring size. The main objectives were to compare offspring size and maternal investment traits within and between populations and to evaluate the relationship between maternal size and offspring size. Although not supported in every population, our results show that maternal size was positively correlated with offspring size, thus representing an example of the maternal size-offspring size correlation in a species in which there is no competition for food between capsule mates because only one embryo develops per capsule. These findings also suggest that in B. deformis larger mothers produce more offspring and provide their offspring with more resources, and that this between-population variation in offspring size is related to differences in the number of nurse eggs allocated per egg capsule and in egg capsule size. The ubiquity of the maternal size-offspring size correlation in B. deformis needs to be tested further across populations, because factors other than maternal size could influence offspring size variation in this marine gastropod.

中文翻译：

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母体大小对直接发育且没有兄弟姐妹相互作用的海洋腹足类动物后代性状的影响

在大多数动物类群中，大母亲（或营养水平高的母亲）会产生较大的后代，从而导致母体大小与后代大小的相关性，即母体大小与后代大小之间的正相关性。在这里，我们使用了变形丁香的三个自然种群之间母体大小的自然变异。（一种具有直接发育能力的海洋蜗牛，可以喂哺哺乳卵，每个卵囊有单个胚胎）来研究母体的投资和后代的大小。主要目标是比较种群内部和种群之间的后代大小和母体投资特征，并评估母体大小和后代大小之间的关系。尽管并非每个人口都支持，但我们的研究结果表明，母体大小与后代大小呈正相关，因此代表了一个物种的母体大小与后代大小相关性的示例，在该物种中，由于只有一个胚胎，胶囊伴侣之间没有食物竞争每个胶囊显影。这些发现还表明在变形双歧杆菌中较大的母亲会生产更多的后代，并为其后代提供更多资源，并且这种种群间差异的后代大小与每个卵囊分配的保育卵数量和卵囊大小的差异有关。变形双歧杆菌的母体大小与后代大小相关性的普遍性需要在整个种群中进行进一步的测试，因为除母体大小以外的其他因素都可能影响该海洋腹足动物的后代大小变化。