Zygnema

Zygnema sp.

Zygnema ( filamentous algae, Sternalge ) is a genus of green algae. It belongs to the family of Zygnemataceae. Zygnema occurs, such as Spirogyra, often in the spring in calm waters as a floating, filamentous, bright green " cotton " on.

It is one of the Jochalgen (multiplication by Jochbildung ), and has no flagellated stages. Each cell contains two large star-shaped chloroplasts.

A special ability of Zygnemataceae is to be able to also utilize the ionic bicarbonate for photosynthesis scarcity of dissolved carbon dioxide. They give off hydroxide so that the pH of the water in the vicinity of the algae cotton may rise to values ​​to 11.