Ulothrix
| Ulothrix | ||||||||||||
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Ulothrix |
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| Scientific name | ||||||||||||
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| Kützing |
Ulothrix is a mainly freshwater genus of green algae in the class Ulvophyceae . It includes about 40 species.
features
The representatives form unbranched threads from a row of cells. The cells are cylindrical. The threads are 5 to 70 micrometers in diameter. The cells have a central or wall-mounted nucleus and a wall-mounted chloroplast . This is large and closed or open ring-shaped, and has several pyrenoids . The growth occurs through cell division in the thread.
The asexual reproduction is effected by the formation of several four geißeliger zoospores in any thread cells. The zoospores enter the open air through pores and then grow into new threads. Sexual reproduction takes place through isogamy : small, two-flagellated gametes that fuse with one another develop in any thread cells. The resulting zygote forms a rhizoid and thus forms a permanent stage ( Codiolum stage). The germination takes place with a reduction division, there are 4 to 16 four-flagellated zoospores, each of which grows into a thread.
Occurrence
The representatives of the genus live firmly in flowing waters and in the moving bank area of lakes. They occur more frequently in spring and autumn, and are rare in summer.
supporting documents
- Karl-Heinz Linne von Berg, Michael Melkonian u. a .: The Kosmos algae guide. The most important freshwater algae under the microscope. Kosmos, Stuttgart 2004, ISBN 3-440-09719-6 , p. 264.
