Rhoicosphenia
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Rhoicosphenia is a genus of diatoms (Bacillariophyta) with around 7 species, one of which is found in freshwater, the other in seawater.
features
The representatives sit on short, not branched to longer, branched gelatinous stems on the ground. The cells have a two-counter shell, which is typical for diatoms. The bowl is curved trapezoidal in side view, in the bowl view it is elongated oval. The side of the cell facing away from the gelatinous stalk is wider. Only one shell has a raphe . The cell nucleus sits in the middle of the cell. There is an H-shaped plastid , its lobes are on the side walls. He has a small pyrenoid . The cell length ranges from 10 to 70 micrometers.
Asexual reproduction occurs through the typical dichotomy of diatoms. Sexual reproduction occurs through isogamy , with two gametes per cell , rarely just one, being formed. The cells then enlarge during the auxospore formation.
Occurrence
Rhoicosphenia mainly lives on solid substrate, on aquatic plants and thread algae. They occur in flowing and standing waters.
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. 228.