Meridion
| Meridion | ||||||||||||
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Meridion circulare |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Meridion | ||||||||||||
| Lyngbye |
Meridion is a genus of diatoms (Bacillariophyta) with about 5 species that only occur in freshwater.
features
Meridion forms colonies that are fan-shaped to circular, rarely spiral-shaped. The individual cells have the typical diatom shell consisting of two counters. The bowl is wedge-shaped in side and bowl view, which results in the curved shape of the colony. The cells are connected to one another at the shell surfaces. The shells have transverse ribs. The cells have a central nucleus and several disc-shaped plastids that are colored golden brown by fucoxanthin . The size is 30 to 250 micrometers.
Asexual reproduction occurs through the typical division of diatoms into two parts, which leads to the reduction of the cells. Sexual reproduction is unknown for the genus.
Occurrence
Meridion lives stuck to the bottom of flowing water. Meridion circulare occurs mainly in calcareous, clean mountain streams.
Types (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. 248.
Web links
- Meridion on algaebase.org
- Entry on Meridion In: MG Kelly, H. Bennion, EJ Cox, B. Goldsmith, J. Jamieson, S. Juggins DG Mann & RJ Telford: Common freshwater diatoms of Britain and Ireland: an interactive key. , Environment Agency, Bristol, 2005