Achnanthes
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| Bory de Saint-Vincent |
Achnanthes is a genus of diatoms (Bacillariophyta) with around 100 species that occur in fresh and marine water.
features
The representatives are rather smaller, single-celled diatoms less than 40 micrometers in length. The individual cells have the typical diatom shell consisting of two counters. The shell is bent in side view, often bent back at the ends in the opposite direction. When viewed from the shell, it is mostly elliptical. The cell is attached to the substrate: either via the raphe directly with the concave shell, or by means of a gelatinous stalk. The second shell has no raphe. The cells have one or two H-shaped plastids that are stained golden brown by fucoxanthin . Some brackish water species have many lenticular plastids.
Asexual reproduction occurs through the typical dichotomy of diatoms. Sexual reproduction occurs through anisogamy , with two gametes being formed per cell . The cells then enlarge during the auxospore formation.
Occurrence
Achnanthes lives mostly fixed on other plants ( epiphytic ) and occurs in all types of water.
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. 202.
