Fragilariopsis cylindrus

Fragilariopsis cylindrus is a pennate raphid diatom with a retangular cell with an elongated apical valve ranging from 15 to 55 μ and a transapical axis ranging from 2.4 to 4 μm. Like other diatoms, F. cylindrus presents a cell wall composed of two biogenic silica valves, the frustule. It is also possible to note the presence of an eccentric raphe canal stretched by fibulae. The cell is generally presents two chloroplasts distributed at each pole of the cell surrounding the cell nucleus. == Life style ==

Fragilariopsis cylindrus is cracterised by a predominantly chain-formed colonial lifestyle and builds large populations at the bottom of sea ice (sea-ice water interface), as well as in the sea-ice margin zone which includes open water. As a sympagic microalgae, F. cylindrus can cope with a high salinity environment, typically found in brine channels, by producing large amounts of polysaccharide-rich extracellular polymeric substances (EPS). F. cylindrus is a phototropic organism, but is able to sustain essential metabolic processes in the dark, ensuring rapid recovery upon re-illumination, and allowing them to survive long-term darkness. == References ==