A new genus of xenophyophores (Foraminifera) from Japan Trench: morphological description, molecular phylogeny and elemental analysis
A new genus of xenophyophores (Foraminifera) from Japan Trench: morphological description, molecular phylogeny and elemental analysis
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DOI：
10.1111/j.1096-3642.2008.00493.x
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发表时间：
2009-07-01
影响因子：
2.8
通讯作者：
Pawlowski, Jan
中科院分区：
文献类型：
--
作者：
Lecroq, Beatrice;Gooday, Andrew John;Pawlowski, Jan
深海海底栖息着许多在浅水沃茨不为人知的不寻常的神秘生物。这些包括异藻体，一组巨大的原生生物，构建脆弱的凝集测试。在此，我们描述了Shinkaiya lindsayi gen. et sp. nov.，日本海沟附近5435 m深的深海潜水器Shinkai 6500采集到一种新的异生植物。对其小亚基核糖体DNA（SSU rDNA）全序列进行系统发育分析，证实Sh. lindsayi sp. nov.是一种有孔虫，与另一种异生植物Syringammina corbicula Richardson，2001和一种单室有孔虫Rhizammina algaeformis布雷迪，1879密切相关。在形态上，新属类似于丁香属，但其测试壁更厚，更软，更弱的胶结。此外，这两个属的SSU rDNA序列高度分歧。质谱分析显示，某些元素的浓度异常高，如铅、铀和汞。颗粒系统（细胞质和包围它的有机鞘）显然没有重晶石晶体，而重晶石晶体通常在异源植物中作为细胞内包裹体而丰富，但富含汞（汞浓度是周围沉积物中汞浓度的12倍）。粪球保留在一个管状系统（stercomare）浓缩重金属，包括铅和铀（分别是沉积物的两倍和六倍）。通过对凝集试验壁、颗粒体、粪体和周围沉积物成分的比较，讨论了异源植物对其生境的影响。(C)2009伦敦林奈学会，林奈学会动物学杂志，2009年，156，455-464。
The deep-sea floor is inhabited by a number of unusual and enigmatic taxa, unknown in shallow waters. These include the xenophyophores, a group of giant protists that construct fragile agglutinated tests. Here, we describe Shinkaiya lindsayi gen. et sp. nov., a new xenophyophore collected by the submersible Shinkai 6500 at a depth of 5435 m near the Japan Trench. The phylogenetic analysis performed on its complete small-subunit ribosomal DNA (SSU rDNA) sequence confirms that Sh. lindsayi sp. nov. is a foraminiferan that is closely related to another xenophyophore, Syringammina corbicula Richardson, 2001, and to a monothalamous (single-chambered) foraminiferan Rhizammina algaeformis Brady, 1879. In terms of morphology, the new genus resembles Syringammina, but its test wall is thicker, softer, and more weakly cemented. Moreover, the SSU rDNA sequences of the two genera are highly divergent. Mass spectra analyses reveal unusually high concentrations of some elements, such as lead, uranium, and mercury. The granellare system (the cytoplasm and the organic sheath that encloses it) is apparently devoid of barite crystals, which are usually abundant as intracellular inclusions in xenophyophores, but is rich in mercury (with 12 times the concentration of mercury found in the surrounding sediment). Fecal pellets retained within a tubular system (stercomare) concentrate heavy metals, including lead and uranium (respectively, two and six times more than that of the sediment). Based on a comparison of the compositions of the agglutinated test wall, the granellare, the stercomare, and the surrounding sediment, we discuss the impact of xenophyophores on their habitat. (C) 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156, 455-464.