Although benthic foraminifera are an important component of meiofauna and contribute to carbonate production and carbon/nitrogen cycles, their role in bioturbation processes remains poorly known. Five dominant intertidal benthic foraminiferal species were recently classified into functional bioturbator groups according to their sediment reworking mode and intensity. Our study aimed at identifying potential drivers (i.e. size and/or travelled distance) of species-specific surface sediment reworking rate. The travelled distance and surface sediment reworking rate of Haynesina germanica, Cribroelphidium williamsoni, Ammonia tepida, Quinqueloculina seminulum and Miliammina fusca were assessed through image analysis. Our results show that the surface sediment reworking performed by these species is not size-dependent, but dependent on their motility traits through interspecific differences in the travelled distance. Smaller species (i.e. Quinqueloculina seminulum and Haynesina germanica) contributed more to surface sediment reworking than larger ones (i.e. Ammonia tepida, Cribroelphidium williamsoni and Miliammina fusca). These observations stress the critical role of motion behaviour in surface sediment reworking processes by intertidal foraminifera. Finally, we stress that the high inter-individual variability observed in conspecific motion behaviour may be important to decipher the role of foraminifera in sediment bioturbation. Noticeably, the species characterized by a strong inter-individual variability are also the species that have the highest surface sediment reworking rates. This last observation may inform on the species-specific phenotypic plasticity and, therefore, the potential for the functional role of these species to be maintained in their natural environment. This is particularly relevant in an era of global change where ecosystem balance is increasingly threatened by various stressors such as heat-waves, ocean acidification and pollution.

尽管底栖有孔虫是小型动物的重要组成部分，并有助于碳酸盐生产和碳/氮循环，但它们在生物扰动过程中的作用仍然知之甚少。五种主要的潮间带底栖有孔虫物种最近根据其沉积物再加工模式和强度分为功能性生物扰动组。我们的研究旨在确定特定物种表层沉积物再加工率的潜在驱动因素（即大小和/或行进距离）。Haynesina Germanica、Cribroelphidium williamsoni、Ammonia tepida、Quinqueloculina seminulum和Miliammina fusca的移动距离和表层沉积物再加工率通过图像分析进行评估。我们的研究结果表明，这些物种进行的表层沉积物改造不依赖于大小，而是通过行进距离的种间差异依赖于它们的运动性状。较小的物种（即Quinqueloculina seminulum和Haynesina Germanica）比较大的物种（即Ammonia tepida、Cribroelphidium williamsoni和Miliammina fusca）对表层沉积物再加工的贡献更大）。这些观察强调了潮间带有孔虫运动行为在表层沉积物改造过程中的关键作用。最后，我们强调在同种运动行为中观察到的高个体间变异性对于破译有孔虫在沉积物生物扰动中的作用可能很重要。值得注意的是，以强烈的个体间变异为特征的物种也是表层沉积物再加工率最高的物种。这最后的观察可能会告知物种特定的表型可塑性，因此，这些物种的功能作用在其自然环境中得以维持的潜力。这在全球变化的时代尤其重要，在这个时代，生态系统平衡越来越受到热浪、海洋酸化和污染等各种压力因素的威胁。