Heavy metal exposure from anthropogenic pollutants negatively affects many marine organisms, including foraminiferan protists. As such, foraminifera are often used as bioindicators of stressed environmental conditions. Primary research has commonly focused on how heavy metals affect foraminiferal assemblages, ultrastructure, and shell morphology; however, little if any data have been reported on how heavy metals affect their physiological functions. Here we measure respiration rates of individual foraminifera after acute exposure to three concentrations of toxic but sub-lethal levels of lead (Pb) and cadmium (Cd). These experiments relied on the large cell size of an agglutinated Antarctic foraminifer, Astrammina rara. Cells were isolated from sediment collected by scuba divers in Explorers Cove, Antarctica. In the laboratory, individual, live cells were removed from their shells and placed in sealed respirometry chambers with either normal or Pb- or Cd-spiked artificial seawater. Cells in the process of shell formation were used to ensure that all individuals were aerobically active and in similar metabolic states. Noninvasive oxygen-sensing optode technology was used to measure oxygen consumption during the first 24–36 h of shell formation. The average respiration rate was 1.07 nmol O₂ h⁻¹ (range 0.78–1.84 nmol O₂ h⁻¹) for normal cells. We compared the results from each exposure group to this baseline rate and found that both Pb and Cd significantly suppressed the respiration rate of A. rara in all but the highest level of Pb exposure. This study provides a novel, powerful, and short-term way to measure foraminiferal physiological responses to heavy metal toxicants.

来自人为污染物的重金属暴露会对许多海洋生物（包括有孔虫生物）产生负面影响。因此，有孔虫通常被用作强调环境条件的生物指示剂。最初的研究通常集中在重金属如何影响有孔虫的组合，超微结构和壳的形态上。但是，关于重金属如何影响其生理功能的数据很少，甚至没有报道。在这里，我们测量了有毒但亚致死水平的铅（Pb）和镉（Cd）三种浓度的急性暴露后单个有孔虫的呼吸速率。这些实验依赖于凝集的南极有孔虫Astrammina rara的大细胞大小。从南极探险家湾潜水员收集的沉积物中分离细胞。在实验室中，将单个活细胞从其外壳中取出，并放入装有普通或铅或镉或镉掺入的人造海水的密封呼吸测定室中。壳形成过程中的细胞用于确保所有个体有氧运动并处于相似的代谢状态。无创氧气传感光电技术用于测量壳形成的最初24–36小时内的氧气消耗。平均呼吸速率为1.07 nmol O ₂ h ^-1（范围0.78–1.84 nmol O ₂ h ^-1）用于正常细胞。我们将每个暴露组的结果与该基线率进行了比较，发现Pb和Cd均显着抑制了A. rara的呼吸速率，但铅暴露水平最高。这项研究提供了一种新颖，有效且短期的方法来测量对有毒金属的有孔虫生理反应。