Ochromonas
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Ochromonas sp. |
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| Scientific name | ||||||||||||
| Ochromonas | ||||||||||||
| Vysotsky |
Ochromonas is a genus of golden brown algae (Chrysophyceae)that occurs in fresh water, and more rarely in sea water. It consists of around 80 species.
features
The representatives are single-cell organisms without a cell wall and have two flagella of unequal length . The cell nucleus lies in the middle of the cell, the one or two golden-brown plastids are attached to the wall. There are one or two contractile vacuoles at the anterior end . The cells have an ophthalmic spot on the plastid. When swimming, the long flagellum is stretched forward, the short flagellum extends backwards and lies above the surface of the eye-spot. The cells are also capable of amoeboid movements.
The asexual reproduction is done by simple longitudinal division. Before the division, two more flagella are formed and divided between the two daughter cells. The sexual reproduction is carried out by isogamy : after the merger of two flagellated gametes to form a continuous cell with silicified wall (Stomatocysten).
Occurrence
The representatives of the genus occur mainly in the cool season, in spring and autumn. They colonize slightly acidic, oligotrophic to slightly mesotrophic waters. They live in the plankton of standing water, but also populate snow.
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. 82.
Web links
- Ochromonas ( Memento from December 23, 2018 in the Internet Archive ) on algaebase.org ( Memento from March 30, 2019 in the Internet Archive )