Oceanic islands and seamounts are considered biodiversity hotspots. Here, we present a taxonomy and community analyses of hyperiid amphipods collected near oceanic islands and over seamounts of the Juan Fernández Archipelago and Desventuradas Archipelago in the South-east Pacific. Both archipelagos are separated by about 800 km over the meridional gradient, suggesting the existence of different hyperiid communities because of apparent geographic isolation and distinctive oceanographic characteristics between regions. To test this hypothesis, zooplankton samples were collected from 19 stations during the CIMAR 22 ‘Oceanic Island’ cruise in October–November 2016. In total, 56 species of hyperiids were found, of which Phrosina semilunata, Lestrigonus schizogeneios, Hyperietta stephenseni, Hyperioides longipes, Phronimella elongata and Primno latreillei were the most abundant and recurrent species. The species richness (S), Shannon–Wiener diversity (H’) and dominance (D) of both the archipelagos were not significantly different. Additionally, except for a small group of rare species, the species composition was similar in both areas. Most species showed greater abundances than those observed in the coastal upwelling zone off Chile, whereas shared species between regions suggested the presence of a single biogeographic unit comprising the coastal transition zone and oceanic area off Chile within which both archipelagos are included. Correlation analysis indicated that salinity was the best predictor for the community structure, which provides evidence that the contributions of previously described water masses of the South-east Pacific may influence the spatial distribution and composition of the hyperiid community.

中文翻译：

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与东南太平洋两个海山区相关的金丝雀片脚类动物群落结构

海洋岛屿和海山被认为是生物多样性热点。在这里，我们对在东南太平洋的胡安·费尔南德斯群岛和德斯文图拉达斯群岛的海洋岛屿附近和海山上采集的金丝虫片脚类动物进行分类和群落分析。两个群岛在经向梯度上相距约 800 公里，这表明由于明显的地理隔离和区域之间独特的海洋学特征，存在不同的超类群落。为了验证这一假设，在 2016 年 10 月至 11 月的 CIMAR 22“海洋岛”航行期间，从 19 个站点收集了浮游动物样本。总共发现了 56 种金丝雀，其中半月草,裂殖酵母,金丝桃,金丝桃,长叶藻和Primno latreillei是最丰富和经常出现的物种。两个群岛的物种丰富度（S）、香农-维纳多样性（H'）和优势度（D）没有显着差异。此外，除少数稀有物种外，两个地区的物种组成相似。大多数物种的丰度高于在智利沿海上升流区观察到的物种，而区域之间共享的物种表明存在一个单一的生物地理单元，包括智利沿海过渡带和海洋区域，其中包括两个群岛。相关分析表明，盐度是群落结构的最佳预测因子，