Cymbella

Cymbella sp.

Cymbella is a genus of diatoms ( Bacillariophyta ) with about 17 species occurring mainly in fresh water.

Features

The representatives are unicellular, elongated diatoms. The individual cells have the typical diatom shell of two counters. The tray is rectangular in side view, in valve view it is asymmetric: one side is strongly convex curved, the other only slightly or quite straight. Rarely, both sides are equally strong curved. The cells have a large, H-shaped plastids with pyrenoid, which is colored by fucoxanthin golden brown. Both shells have a raphe. The cells are able to creep. They can be fixed by a handle on the gelatinous surface. Some species form by gelatinous sheaths colonies. Cell length ranging from 10 to 220 micrometers.

Asexual reproduction occurs by the typical dichotomy of diatoms. Sexual reproduction takes place by isogamy or Anisogamie, where two gametes per cell, are rarely only one formed. Following Auxosporenbildung during the cell enlargement takes place.

Occurrence

Cymbella lives on plants ( epiphytes ) or as plankton. They occur in oligotrophic to eutrophic waters and springs.

Documents

• K.-H. Linne von Berg, K. Hoef -Emden, B. Marin, M. Melkonian: The Cosmos algae leader. The main freshwater algae under the microscope. Kosmos, Stuttgart 2004, pp. 212, ISBN 3-440-09719-6