Sun Jin, Zhou Yadong, Chen Chong, Kwan Yick Hang, Sun Yanan, Wang Xuyang, Yang Lei, Zhang Ruiyan, Wei Tong, Yang Yi, Qu Lingyun, Sun Chengjun, Qian Pei-Yuan
Marine Bioresource and Environment Research Center, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, People's Republic of China.
Department of Ocean Science, Division of Life Science and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, People's Republic of China.
R Soc Open Sci. 2020 Mar 25;7(3):200110. doi: 10.1098/rsos.200110. eCollection 2020 Mar.
Biodiversity of hydrothermal vents in the Indian Ocean, particularly those on the Southwest Indian Ridge (SWIR), are still relatively poorly understood. The Tiancheng field on the SWIR was initially reported with only a low-temperature diffuse flow venting area, but here we report two new active areas, including a chimney emitting high-temperature vent fluids. Biological sampling in these new sites doubled the known megafauna and macrofauna richness reported from Tiancheng. Significantly, we found several iconic species, such as the scaly-foot snail and the first population on the SWIR. Tiancheng shares a high proportion of taxa with vents on the Central Indian Ridge (CIR) and lacks a number of key taxa that characterize other vents investigated so far on the SWIR. Population genetics of the scaly-foot snail confirmed this, as the Tiancheng population was clustered with populations from the CIR, showing low connectivity with the Longqi field. Unlike the previously examined populations, scales of the Tiancheng scaly-foot snail were coated in zinc sulfide, although this results only from precipitation. The close connection between Tiancheng and CIR vents indicates that the dispersal barrier for vent endemic species is not the Rodriguez Triple Junction as previously suggested but the transformation faults between Tiancheng and Longqi, warranting further studies on deep currents in this area to resolve the key barrier, which has important implications for biological conservation.
印度洋热液喷口的生物多样性，尤其是西南印度洋海岭（SWIR）上的热液喷口，目前仍了解得相对较少。SWIR上的天成热液区最初报道时仅有一个低温扩散流排放区域，但在此我们报告了两个新的活跃区域，包括一个排放高温喷口流体的烟囱。在这些新地点进行的生物采样使天成已知的大型动物和巨型动物丰富度增加了一倍。值得注意的是，我们发现了几种标志性物种，如鳞足蜗牛以及SWIR上的首个种群。天成与中印度洋海岭（CIR）的热液喷口有很高比例的分类群相同，并且缺乏一些迄今为止在SWIR上其他已调查热液喷口所特有的关键分类群。鳞足蜗牛的种群遗传学证实了这一点，因为天成种群与CIR的种群聚类在一起，与龙旗热液区的连通性较低。与之前检查的种群不同，天成鳞足蜗牛的鳞片覆盖有硫化锌，不过这仅是沉淀的结果。天成与CIR热液喷口之间的紧密联系表明，热液特有物种的扩散障碍并非如先前所认为的是罗德里格斯三联点，而是天成与龙旗之间的转换断层，这需要对该区域的深层洋流进行进一步研究以解决这个关键障碍，这对生物保护具有重要意义。
