Pediastrum
| Pediastrum | ||||||||||
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| Scientific name | ||||||||||
| Pediastrum | ||||||||||
| Meyen |
Pediastrum is a genus of colony forming green algae from the class of Chlorophyceae .
features
The individual cells with a diameter of 8–32 µm form a typical, flat, round and disk-shaped aggregation structure, a coenobium . This consists of 4 to 128 individual cells with a total diameter of up to 450 µm. The cells have a single nucleus and a single chloroplast with a pyrenoid . The shape of the cells is polygonal with concave or convex sides. In contrast to those in the middle, the marginal cells have outwardly directed processes.
Asexual reproduction occurs through the formation of 2 n bifurcated zoospores or immobile aplanospores . These leave the mother cell in a bubble and form a daughter colony within this bubble. Sexual reproduction occurs through isogamy . The cells of the colony form two- flagged gametes that fuse to form a hypno zygote . Movable meiospores arise from this after reduction division. The meiospores transform into polyhedral, immobile cells. In these zoospores develop, which leave the sporangium as in asexual reproduction in a bubble.
Occurrence
Pediastrum occurs in freshwater plankton from arctic to tropical climates. It can form water flowers. It also occurs in the growth of eutrophic , stagnant water. It occurs all year round.
Systematics
Algaebase names 29 recognized species.
Selection:
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. 196.
- McManus, HA & Lewis, LA (2011). Molecular phylogenetic relationships in the freshwater family Hydrodictyaceae (Sphaeropleales, Chlorophyceae), with an emphasis on Pediatrum duplex. Journal of Phycology 47 (1): 152-163.
- Tsarenko, PM (2011). Sphaeropleales. In: Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography. Volume 3: Chlorophyta. (Tsarenko, PM, Water, SP & Nevo, E. Eds), pp. 280-355. Ruggell: ARA Gantner Verlag K.-G.
- A. Bresinsky, Ch. Körner, JW Kadereit, G. Neuhaus, Uwe Sonnewald: Strasburger - Textbook of Botany, Spectrum Academic Publishing House; Edition: 36 (2008)
Individual evidence
- ↑ Pediastrum on algaebase.org , accessed March 20, 2011.
