The trophic ecology of xenophyophores (Foraminifera, Rhizaria) was examined during a 2-day in situ feeding experiment on the seafloor (water depths of 5370 m) off the east coast of Torishima Island, Japan. Both ¹³C-labeled glucose (as an example of labile dissolved organic matter) and ¹⁵N-labeled diatoms (as an example of labile particulate organic matter sinking from the ocean surface) were supplied to the specimens captured in in-situ incubation cores using the manned submersible Shinkai 6500. We found that xenophyophores took up both dissolved and particulate organic matter during the 2 days of incubation in situ. The higher concentrations of ¹⁵N-labeled diatoms in the xenophyophores than in the surrounding sediments suggest efficient collection and use of food resources by xenophyophores, and may support their rapid growth. It is likely that the agglutinated test of xenophyophores, which forms a contorted plate-like structure with upper open fan-like and funnel-like elements, also contributes to their ability to collect phytodetritus derived from the ocean surface.

在日本鸟岛东海岸的海底（水深 5370 米）上进行了为期 2 天的原位取食实验，对 Xenophyophores（Foraminifera、Rhizaria）的营养生态进行了检查。两个¹³ C标记的葡萄糖（如不稳定的溶解的有机物质的实例）和¹⁵ N-标记的硅藻（作为不稳定颗粒有机物质从海洋表面下沉的一例）供给至中捕获的标本中-原位使用孵育芯载人潜水器新海6500。我们发现，在 2 天的原位培养期间，外生藻吸收了溶解的和颗粒状的有机物质。较高的浓度¹⁵ N 标记的硅藻在外生藻中比在周围沉积物中表明外生藻有效地收集和利用食物资源，并可能支持它们的快速生长。有可能形成具有上部开放扇状和漏斗状元素的扭曲板状结构的外生藻的凝集试验也有助于它们收集来自海洋表面的植物碎屑的能力。