Nutritional sources of meio- and macrofauna at hydrothermal vents and adjacent areas: natural-abundance radiocarbon and stable isotope analyses
Nutritional sources of meio- and macrofauna at hydrothermal vents and adjacent areas: natural-abundance radiocarbon and stable isotope analyses
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DOI：
10.3354/meps13053
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发表时间：
2019-07-18
影响因子：
2.5
通讯作者：
Shimanaga, Motohiro
中科院分区：
文献类型：
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作者：
Nomaki, Hidetaka;Uejima, Yuki;Shimanaga, Motohiro
深海热液喷口拥有独特的海洋生态系统，这些生态系统依赖化能自养微生物和植物碎屑产生的有机物。虽然小型底栖生物在这些喷口可能很丰富，但小型底栖生物体积小，限制了对营养来源的研究。在这里，我们调查了饮食来源的小型和大型底栖动物在热液喷口领域在西北太平洋使用稳定的碳和氮同位素比值（三角洲C-13，三角洲N-15）和自然丰度放射性碳（三角洲C-14）。细菌垫和Paralvinella spp.从热液喷口烟囱收集的多毛类化石中的碳-13富集（高达千分之-10），碳-14贫化（千分之-700至-580）。热液喷口烟囱特有的双头桡足类的δ C-13和δ C-14值分别为-11ppm和-661ppm，与细菌垫和Paralvinella spp中的值相似。但与附近的非喷口沉积物（三角洲C-13：类似于千分之-24）和水柱浮游生物（三角洲C-14：类似于千分之40）不同。相比之下，喷口烟囱中线虫的δ C-13值与非喷口地点的相似（约100 ℃）。- 千分之25）。结果表明，dirivultids依赖于通风烟囱细菌垫作为其营养源，而通风口线虫没有获得显着的营养量从chemolithoautotrophic微生物。三角洲C-14值的Neoverruca intermedia（发泄藤壶）表明，他们获得营养化能自养微生物，但无机碳的来源被稀释的底层水远远超过那些Paralvinella栖息地，反映Neoverruca的更远的分布从活跃的排气。对热液喷口生物的稳定同位素和放射性同位素分析相结合，提供了关于其营养来源的宝贵信息，从而也提供了关于其对以化学合成为基础的生态系统的适应性生态的信息。
Deep-sea hydrothermal vents host unique marine ecosystems that rely on organic matter produced by chemoautotrophic microbes together with phytodetritus. Although meiofauna can be abundant at such vents, the small size of meiofauna limits studies on nutritional sources. Here we investigated dietary sources of meio- and macrofauna at hydrothermal vent fields in the western North Pacific using stable carbon and nitrogen isotope ratios (delta C-13, delta N-15) and natural-abundance radiocarbon (Delta C-14). Bacterial mats and Paralvinella spp. (polychaetes) collected from hydrothermal vent chimneys were enriched in C-13 (up to -10 parts per thousand) and depleted in C-14 (-700 to -580 parts per thousand). The delta C-13 and Delta C-14 values of dirivultid copepods, endemic to hydrothermal vent chimneys, were -11 parts per thousand and -661 parts per thousand, respectively, and were similar to the values in the bacterial mats and Paralvinella spp. but distinct from those of nearby non-vent sediments (delta C-13: similar to-24 parts per thousand) and water-column plankton (Delta C-14: similar to 40 parts per thousand). In contrast, delta C-13 values of nematodes from vent chimneys were similar to those of non-vent sites (ca. -25 parts per thousand). Results suggest that dirivultids relied on vent chimney bacterial mats as their nutritional source, whereas vent nematodes did not obtain significant nutrient amounts from the chemolithoautotrophic microbes. The Delta C-14 values of Neoverruca intermedia (vent barnacle) suggest they gain nutrition from chemoautotrophic microbes, but the source of inorganic carbon was diluted with bottom water much more than those of the Paralvinella habitat, reflecting Neoverruca's more distant distribution from active venting. The combination of stable and radioisotope analyses on hydrothermal vent organisms provides valuable information on their nutritional sources and, hence, their adaptive ecology to chemosynthesis-based ecosystems.