1. Population connectivity has a fundamental role in metapopulation dynamics, with important implications in conservation. Easter Island (EI) and Salas y Gómez Island (SG) in the Pacific Ocean are ideal for the study of population connectivity because they are separated by 415 km and isolated from other islands in the Pacific Ocean by >2,000 km.
2. Considering that dispersal processes could play a critical role in the persistence of its populations, the connectivity pattern of the rudderfish Kyphosus sandwicensis was evaluated between EI and SG using both a population genetics and a biophysical modelling approach.
3. The variability in the control region of the mitochondrial DNA did not show a significant phylogeographical pattern, and the variability in 16 microsatellite loci suggested that individuals of K. sandwicensis located at EI and SG belong to the same genetic population. However, historical migration showed that 0.2% of the recruits at EI come from SG and that 0.15% at SG come from EI per year.
4. Using simulated larval release during September and a larval development of 30 days in the plankton, biophysical modelling did not detect migration between the islands. Furthermore, self‐recruitment shows interannual variation ranging from 5 to 10% of the total released larvae.
5. Whereas the genetic data showed a lack of population genetic structure but low connectivity of K. sandwicensis between EI and SG, the biophysical modelling showed null movement of particles between the islands. Stochastic movement of larvae or adults could explain the pattern observed, with rafting as an example. These low‐frequency and stochastic movements may be important in maintaining the cohesiveness between EI and SG.

中文翻译：

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居住在偏远海洋岛屿的鱼Kyphosus sandwicensis（Teleostei：Kyphosidae）的弱连通性和种群凝聚力

1. 人口连通性在种群动态中具有基本作用，对保护具有重要意义。太平洋的复活节岛（EI）和萨拉斯·戈麦斯岛（SG）是研究人口连通性的理想选择，因为它们相距415公里，与太平洋其他岛屿相距> 2,000公里。
2. 考虑到扩散过程可能对其种群的持久性起关键作用，使用种群遗传学和生物物理建模方法对EI和SG之间的fish鱼Kyphosus sandwicensis的连通性模式进行了评估。
3. 线粒体DNA的控制区域中的变异性没有显示出明显的系统地理学模式，并且在16个微卫星基因座中的变异性表明位于EI和SG的沙生克氏杆菌个体属于同一遗传种群。但是，历史迁移表明，每年EI的新兵中有0.2％来自SG，而SG的新兵中的0.15％则来自EI。
4. 使用9月期间模拟的幼虫释放和浮游生物中30天的幼虫发育，生物物理模型未检测到岛屿之间的迁移。此外，自我招募显示出年际变化，占总释放幼虫的5％至10％。
5. 遗传数据显示缺乏种群遗传结构，而EI和SG之间沙棘K. sandwicensis的连通性较低，但生物物理模型显示岛屿之间的颗粒没有运动。幼虫或成虫的随机运动可以解释观察到的模式，以漂流为例。这些低频和随机运动对于维持EI和SG之间的凝聚力可能很重要。