Figuerola Blanca, Barnes David K A, Brickle Paul, Brewin Paul E
Biodiversity Research Institute (IRBio), Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028 Barcelona, Catalonia, Spain.
British Antarctic Survey (BAS), Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK.
Mar Environ Res. 2017 May;126:81-94. doi: 10.1016/j.marenvres.2017.02.005. Epub 2017 Feb 21.
There are a number of remote archipelagos distributed between 45 and 60 °S. The biota of these islands provide useful information to describe and understand patterns in biodiversity and biogeography as well as potential impacts of climate change on marine ecosystems. They are in key locations either side of the Polar Front but also have limited influence from human activities. Here we investigate one taxon, bryozoans, on South Atlantic shelf habitats of the Falkland (FI) and the sub-Antarctic island of South Georgia (SG). We present new data on spatial distribution in these islands, as well as an analysis of the bryozoological similarities between these and neighbouring regions. A total of 85 species of cheilostome bryozoans (351 samples) were found, belonging to 33 genera, including 18 potentially new genera and 23 new species. Remarkably 65% and 41% of species were reported for the first time at FI and SG, respectively. The highest and the lowest value of species richness and species/genus ratio were found at East (EFI) and West Falkland (WFI), respectively, likely showing a tendency for stronger intrageneric competition. New data from this study were jointly analysed with data from the literature and existing databases, revealing new bathymetric ranges in 32 species. The biogeographic affinities of the bryozoans found give further evidence of the hypothesis of sequential separation of Gondwana and support the changing concept that although the Polar Front acts as a circumpolar biogeographic barrier it is not as impermeable as originally thought. Potential dispersal mechanisms are also discussed.
有许多偏远群岛分布在南纬45度至60度之间。这些岛屿的生物群为描述和理解生物多样性与生物地理学模式以及气候变化对海洋生态系统的潜在影响提供了有用信息。它们位于极地锋两侧的关键位置，但受人类活动的影响也有限。在这里，我们研究了福克兰群岛（FI）的南大西洋陆架栖息地以及亚南极的南乔治亚岛（SG）上的一个分类群——苔藓虫。我们展示了这些岛屿上苔藓虫空间分布的新数据，以及对这些岛屿与邻近区域之间苔藓虫学相似性的分析。共发现了85种唇口目苔藓虫（351个样本），分属于33个属，包括18个潜在新属和23个新物种。值得注意的是，分别有65%和41%的物种是在FI和SG首次被报道。物种丰富度和物种/属比率的最高值和最低值分别出现在东福克兰群岛（EFI）和西福克兰群岛（WFI），这可能表明存在更强的属内竞争趋势。本研究的新数据与文献和现有数据库中的数据进行了联合分析，揭示了32个物种新的水深分布范围。所发现的苔藓虫的生物地理亲缘关系进一步证明了冈瓦纳大陆相继分离的假说，并支持了这样一种不断变化的观念，即尽管极地锋是一个环极生物地理屏障，但它并不像最初认为的那样不可渗透。还讨论了潜在的扩散机制。
