Oedogonium
| Oedogonium | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Oedogonium spec. |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Oedogonium | ||||||||||||
| link |
Oedogonium (German cap algae ) is a species from the green algae group of the Chlorophyceae that occurs in freshwater. It includes around 450 species.
features
The representatives form unbranched threads from a row of cells. The threads are 3 to 60 micrometers in diameter. The cell nucleus sits in the middle of the cell, the chloroplasts are wall-like, network-shaped and have pyrenoids . The formation of cap cells makes the genus unmistakable: during vegetative cell division within the thread, one daughter cell forms a ring-shaped cap, the second does not. This is repeated with every cell division, so that cap cells can have many terminal caps.
The asexual reproduction is carried out by large, stephanokonte zoospores . These escape individually from normal thread cells. The sexual reproduction is done by oogamy : individual cells form a bulbous oogonium. One or two male spermatozoids are formed in special short cells ( antheridium ) . After fertilization , a permanent zygote arises . Many species form dwarf males as an intermediate stage: the flagellated cell released from the short cell does not fuse with the egg cell, but attaches itself to the oogonium and forms a small, few-celled thread here, the so-called dwarf male. This forms one or two antheridia, from each of which a spermatozoid escapes.
Occurrence
The representatives of the genus live predominantly (somewhat in the form of fur algae ) in stagnant or flowing, predominantly nutrient-poor waters. They are less likely to be free-floating. They occur mainly in spring.
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. 260.
Web links
- Oedogonium on algaebase.org
- Aquamax: Algae Database
Individual evidence
- ↑ Ricardo Castellanos: Fur algae. Oedogonium sp. ( Logemann's Shrimp House. June 4, 2018).