Density drives polyandry and relatedness influences paternal success in the Pacific gooseneck barnacle, Pollicipes elegans

Background: Polyandry is a common mating strategy in animals, increasing female fitness through direct (material) and indirect (genetic) benefits. Most theories about the benefits of polyandry come from studies of terrestrial animals, which have relatively complex mating systems and behaviors; less is known about the potential benefits of polyandry in sessile marine animals, for which potential mates may be scarce and females have less control over pre-copulatory mate choice. Here, we used microsatellite markers to examine multiple paternity in natural aggregations of the Pacific gooseneck barnacle Pollicipes elegans, testing the effect of density on paternity and mate relatedness on male reproductive success.
Results: We found that multiple paternity was very common (79% of broods), with up to five fathers contributing to a brood, though power was relatively low to detect more than four fathers. Density had a significant and positive linear effect on the number of fathers siring a ...

背景：一妻多夫制（Polyandry）是动物中常见的交配策略，通过直接（物质）和间接（遗传）收益提升雌性适合度。多数关于一妻多夫制收益的理论源于陆生动物研究，这类动物具有相对复杂的交配系统与行为；而固着型海洋动物中一妻多夫制的潜在收益尚不明确——此类动物的潜在配偶可能稀缺，且雌性对交配前配偶选择的控制能力较弱。本研究采用微卫星标记（microsatellite markers），考察太平洋鹅颈藤壶（Pollicipes elegans）自然聚集群体中的多父权（multiple paternity）现象，验证密度对父权数量的影响及配偶亲缘关系对雄性繁殖成功率的作用。

结果：研究发现多父权现象极为普遍（79%的繁殖群），单个繁殖群最多可由5个雄性贡献父系遗传，不过检测超过4个雄性的统计效力（statistical power）相对较低。密度对为繁殖群贡献父系的雄性数量具有显著的正向线性效应……