Some aspects of the life cycle of the Southern Ocean diatom Fragilariopsis kerguelensis have been investigated previously, but many of its details have not been surveyed in nature. We investigated material from a two-year sediment trap time series by high-throughput imaging and image analysis, looking for morphometric signals of life cycle stages. Valve length distributions appeared close to unimodal but positively (right-) skewed. Size cohorts resulting from synchronized sexual reproduction events were not clearly distinguishable. Nevertheless, based on changes in valve length distributions, we found three general seasonal phases. These corresponded to periods of proliferation (with higher proportions of smaller cells during late spring/early summer), cessation of growth (relative loss of smaller cells during late summer/early autumn), and overwintering (little change in size distributions, with an increased proportion of large cells). We discuss possible causes of these signals, and their relevance to growth, sexual activity and adaption to environmental conditions, such as grazing pressures and the need for an overwintering strategy.

中文翻译：

---

通过沉积物捕集器样品的高通量显微镜观察南大洋硅藻 Fragilariopsis kerguelensis 尺寸分布的时间变化

之前已经对南大洋硅藻 Fragilariopsis kerguelensis 生命周期的某些方面进行了调查，但其许多细节尚未在自然界中进行调查。我们通过高通量成像和图像分析研究了两年沉积物捕集时间序列中的材料，寻找生命周期阶段的形态测量信号。瓣膜长度分布似乎接近单峰但正（右）偏斜。由同步有性生殖事件产生的大小队列不能清楚地区分。然而，基于阀门长度分布的变化，我们发现了三个一般的季节性阶段。这些对应于增殖期（春末/夏初较小细胞的比例较高），生长停止（夏末/初秋较小细胞的相对损失），和越冬（尺寸分布变化不大，大细胞比例增加）。我们讨论了这些信号的可能原因，以及它们与生长、性活动和适应环境条件（例如放牧压力和越冬策略的必要性）的相关性。