Temporal changes in size distributions of the Southern Ocean diatom Fragilariopsis kerguelensis through high-throughput microscopy of sediment trap samples

• Main Authors: Kloster, Michael, Rigual-Hernández, Andrés S., Armand, Leanne K., Kauer, Gerhard, Trull, Thomas W., Bánk Beszteri
• Format: Dataset
• Language: unknown
• Published: Taylor & Francis 2019
• Subjects: Cell Biology; 59999 Environmental Sciences not elsewhere classified; FOS Earth and related environmental sciences; Ecology; FOS Biological sciences; 69999 Biological Sciences not elsewhere classified; Inorganic Chemistry; FOS Chemical sciences; Southern Ocean
• Online Access: https://dx.doi.org/10.6084/m9.figshare.9678005.v1; https://tandf.figshare.com/articles/Temporal_changes_in_size_distributions_of_the_Southern_Ocean_diatom_i_Fragilariopsis_kerguelensis_i_through_high-throughput_microscopy_of_sediment_trap_samples/9678005/1

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.