Li Haotian, Lei Yanli, Fa Wenlong, Wu Tianzhen, Li Tiegang
Laboratory of Marine Organism Taxonomy and Phylogeny, Qingdao Key Laboratory of Marine Biodiversity and Conservation Institute of Oceanology, Chinese Academy of Sciences Qingdao China.
Laboratory for Marine Biology and Biotechnology Qingdao Marine Science and Technology Center Qingdao China.
Ecol Evol. 2024 Oct 10;14(10):e70243. doi: 10.1002/ece3.70243. eCollection 2024 Oct.
Foraminifera is the most important temperature proxy of the ocean on long time scales. However, the absence of temperature-controlled experiments at different water depths hinders the advancement of paleotemperature reconstruction with foraminifera from the continental shelf. For the first time, this study investigated the response of benthic foraminifera to temperature change using microcosm culture and metabarcoding. Foraminiferal communities from three continental stations at varying water depths (6.0, 9.2, and 26.0 m) were cultured under five temperature gradients (6, 12, 18, 24, and 30°C), with each treatment performed in triplicate. The foraminifera were fed with microalgae every 4 days, and the filtered seawater (through 0.22 μm pores), acting as a medium, was changed accordingly. The experiment lasted for 80 days, and 47 DNA samples were obtained and analyzed, including three in situ samples. The results showed that foraminifera adjusted its growth rate within the low-temperature range and adopted an r-strategy to cope with high-temperature stress. In addition, the foraminifera from deeper water stations exhibited a pronounced vulnerability to diminishing read counts. The read counts, operational taxonomic units (OTU) counts and Margalef index of foraminifera and the read counts of Rotaliida exhibited a remarkably positive correlation with temperature. The recommended relationships were described as read counts = 1314.75T + 44754.51; OTU counts = 1.13T + 44.26; Margalef index =1.13*T + 44.26. This study established the first quantitative relationship between temperature and foraminifera molecular parameters that holds significant implications for long-time paleotemperature calibration in climate change.
有孔虫是海洋在长时间尺度上最重要的温度指标。然而，缺乏在不同水深进行的温度控制实验阻碍了利用大陆架有孔虫进行古温度重建的进展。本研究首次使用微观培养和代谢条形码技术研究了底栖有孔虫对温度变化的响应。来自三个不同水深（6.0、9.2和26.0米）大陆站点的有孔虫群落，在五个温度梯度（6、12、18、24和30°C）下进行培养，每个处理重复三次。每4天给有孔虫投喂微藻，并相应更换作为介质的经过0.22μm孔径过滤的海水。实验持续了80天，共获得并分析了47个DNA样本，包括三个原位样本。结果表明，有孔虫在低温范围内调整其生长速率，并采用r策略来应对高温胁迫。此外，来自较深水站点的有孔虫对读数减少表现出明显的脆弱性。有孔虫的读数、操作分类单元（OTU）数量和马加利夫指数以及轮虫目的读数与温度呈现出显著的正相关。推荐的关系描述为：读数 = 1314.75T + 44754.51；OTU数量 = 1.13T + 44.26；马加利夫指数 = 1.13*T + 44.26。本研究建立了温度与有孔虫分子参数之间的首个定量关系，这对气候变化中的长期古温度校准具有重要意义。
