(Table 2) Rate of reduction in cell size (apical length) and growth rate for seven Fragilariopsis kerguelensis strains sampled during POLARSTERN cruise ANT-XXI/3 ...

• Main Authors: Fuchs, Nike, Scalco, Eleonora, Kooistra, W H C F, Assmy, Philipp, Montresor, Marina
• Format: Dataset
• Language: English
• Published: PANGAEA 2013
• Subjects: AWI; Event label; Date/Time of event; Latitude of event; Longitude of event; Species; Strain; Cell size; Cell division rate; Cell size decrease; Cell size decrease per division; Hand net; ANT-XXI/3; Polarstern; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas SPP1158; Antarc*; Antarctic; Sea ice; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.847739; https://doi.pangaea.de/10.1594/PANGAEA.847739

The planktonic diatom Fragilariopsis kerguelensis plays an important role in the biogeochemical cycles of the Southern Ocean, where remains of its frustules form the largest deposit of biogenic silica anywhere in the world. We assessed the genetic identity of 26 strains, from cells collected at various sites in the Southern Ocean, using three molecular markers, LSU and ITS rDNA and rbcL. The LSU sequences were identical among the tested strains, ITS sequences were highly similar, and only one base pair difference was detected among the rbcL sequences. These results, together with a large number of successful mating experiments demonstrated that the strains belong to a single biological species. We investigated the mating system and life cycle traits of F. kerguelensis. Cell size diminished gradually in clonal strains. Gamete formation only occurred when strains of opposite mating type - within a cell size range of 7-36 µm - were mixed together. Two binucleate gametes were formed in each gametangium and ... : The cell size is the average cell size on day 0 and the growth rate is the average of three measurements. ...