Diatoma
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| Lyngbye |
Diatoma is a genus of diatoms (Bacillariophyta) with about 7 species that only occur in freshwater.
features
Diatoma forms colonies from single cells connected in a ribbon or zigzag fashion . The individual cells have the typical diatom shell consisting of two counters. This is rectangular in side view, linear to elliptical in shell view. It has clear horizontal stripes and is thickened at the ends. They have a central nucleus and several plastids that are colored golden brown by fucoxanthin . The cells are alternately connected at the cell ends or on the entire bowl lid. They therefore always appear in side view. The size is 8 to 120 microns.
Asexual reproduction occurs through the typical division of diatoms into two parts, which leads to the reduction of the cells. The sexual reproduction is carried out at Diatoma by anisogamy , wherein two gametes are formed per cell. After the fusion, cells expand as part of the auxospore formation. Permanent cells can also be formed directly from vegetative cells.
Occurrence
Diatoma lives in benthos of flowing and standing water, but is also found in plankton .
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. 242.
Economical meaning
Some researchers have recently attributed particular economic importance to the algae as a future mass-produced biofuel , because of its oily core and its high rate of multiplication .
Web links
Individual evidence
- ^ Oil Rig of the Future: A Solar Panel That Produces Oil - Researchers propose a novel approach to producing biofuel using diatoms , in: Scientific American ", September 17, 2009.