Ichthyology Section, Department of Marine Zoology, Senckenberg Research Institute and Museum of Nature, Senckenberg Society of Nature Research, Frankfurt am Main, Germany.
Department of Biogeography and Ecosystem Research, Quantitative Biogeography Group, Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberg Society of Nature Research, Frankfurt am Main, Germany.
PLoS One. 2022 Apr 29;17(4):e0267086. doi: 10.1371/journal.pone.0267086. eCollection 2022.
The Socotra Archipelago, located in the eastern Gulf of Aden, has a unique marine environment, which combines tropical and 'pseudo-temperate' elements. An updated species inventory recently considered its coastal fish diversity the highest among Arabian ecoregions, necessitating to re-assess the ichthyogeographic position of the island group. The main aim of this study is to describe the distributional biogeography of its coastal fish fauna in relation to contemporary ichthyogeographic and ecoregional concepts. Inferences are drawn with regard to the marine biogeographic arrangement and ecoregional partitioning of the Arabian region. The main datasets comprise eight and twenty selected families including 404 and 898 species, respectively, from Arabian ecoregions. The Socotra Archipelago has close affinities to a putative ecoregion in the eastern Gulf of Aden that extends to southern Oman. It is more closely related to the Arabian Sea coast of Oman than to ecoregions in the Red Sea and a putative ecoregion in the western Gulf of Aden. The Gulf of Aden does not represent a consistent ecoregion in ichthyogeographic terms, because its eastern and western parts are less closely related to one another than to other ecoregions. The Socotra Archipelago and the eastern Gulf of Aden should therefore not be assigned to a joined province with Red Sea ecoregions. The coastal fish faunas of the southern Red Sea have close affinities with those of the western Gulf of Aden. The Arabian/Persian Gulf is least related to the other Arabian ecoregions. The authors posit the Socotra Archipelago as a distinct ecoregion, either on its own or in combination with affiliated mainland areas. This best reflects the ichthyogeographic data and the exceptionally high levels of fish and overall marine diversity. Two alternative ecoregional delineations are proposed, serving as working hypotheses for onward research.
索科特拉群岛位于亚丁湾东部，拥有独特的海洋环境，融合了热带和“准温带”元素。最近的一项物种清单更新认为，其沿海鱼类多样性在阿拉伯生态区中最高，因此需要重新评估该岛群的鱼类地理分布位置。本研究的主要目的是描述其沿海鱼类区系与当代鱼类地理和生态区概念的分布生物地理学。就阿拉伯地区的海洋生物地理排列和生态区划分得出结论。主要数据集包括来自阿拉伯生态区的八个和二十个选定科，分别包含 404 和 898 个物种。索科特拉群岛与亚丁湾东部一个假定的生态区密切相关，该生态区延伸至阿曼南部。它与阿曼阿拉伯海沿岸的关系比与红海和亚丁湾西部一个假定的生态区更为密切。从鱼类地理角度来看，亚丁湾不是一个一致的生态区，因为其东部和西部彼此之间的关系不如与其他生态区的关系密切。因此，不应将索科特拉群岛和亚丁湾东部归入与红海生态区联合的省份。红海南部的沿海鱼类区系与亚丁湾西部的鱼类区系密切相关。阿拉伯/波斯湾与其他阿拉伯生态区的关系最不密切。作者将索科特拉群岛视为一个独特的生态区，无论是单独还是与相关的大陆地区结合。这最能反映鱼类地理数据和鱼类及整体海洋生物多样性的极高水平。提出了两种替代的生态区划定，作为进一步研究的工作假设。
