Chlorarachniophyta
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Scientific name | ||||||||||||
Chlorarachniophyta | ||||||||||||
Hibberd & RE Norris , 1984 |
The Chlorarachniophyta are amoeboid eukaryotes from the group of Rhizaria , which have chloroplasts through secondary endosymbiosis . In the classical system, they were placed among the green algae because of these chloroplasts .
features
All species are unicellular with bare amoeboid cells. They form reticulated pseudopodia with extrusomes .
The chloroplasts are bright green and contain chlorophyll a and b. The thylakoids form stacks of two to six. The chloroplast is surrounded by four membranes. It also contains a nucleomorph within the first two membranes . This is interpreted as the residual nucleus : the amoeba has absorbed a eukaryotic, photoautotrophic unicellular organism, probably a green alga , in endosymbiosis . The endosymbiont is largely reduced, apart from the chloroplast only the nucleomorph, the membrane of the guest and the endocytosis membrane of the host are present. In addition to the nucleomorph, there is a pyrenoid between the membranes . The main storage carbohydrate is a β-1,3- glucan . The cristae of the mitochondria form tubules.
The motile cells of the spreading stage have two cilia .
Sexual reproduction has been observed but has not been studied in detail.
nutrition
Although they are capable of photosynthesis due to their chloroplasts, they have a mixotrophic diet : they also catch bacteria , flagellates and eukaryotic algae .
Occurrence
The species live in warm seas around the world.
Systematics
The Chlorarachniophyta include four genera with six described species, including:
- Bigelowiella natans
- Chlorarachnion reptans
- Chryptochlora perforans
- Lotharella globosa
- Lotharella amoeboformis
Other species that have not yet been described are known. The total number is estimated to be around 100 species.
Sources and further information
literature
- Sina M. Adl, Alastair GB Simpson, Mark A. Farmer, Robert A. Andersen, O. Roger Anderson, John A. Barta, Samual S. Bowser, Guy Bragerolle, Robert A. Fensome, Suzanne Fredericq, Timothy Y. James, Sergei Karpov, Paul Kugrens, John Krug, Christopher E. Lane, Louise A. Lewis, Jean Lodge, Denis H. Lynn, David G. Mann, Richard M. McCourt, Leonel Mendoza, Øjvind Moestrup, Sharon E. Mozley-Standridge, Thomas A. Nerad, Carol A. Shearer, Alexey V. Smirnov, Frederick W. Spiegel, Max FJR Taylor: The New Higher Level Classification of Eukaryotes with Emphasis on the Taxonomy of Protists. The Journal of Eukaryotic Microbiology 52 (5), 2005; Pages 399-451. doi : 10.1111 / j.1550-7408.2005.00053.x .
- Peter Sitte , Elmar Weiler , Joachim W. Kadereit , Andreas Bresinsky , Christian Körner : Textbook of botany for universities . Founded by Eduard Strasburger . 35th edition. Spektrum Akademischer Verlag, Heidelberg 2002, ISBN 3-8274-1010-X .
- David J. Hibberd, Richard E. Norris: Cytology and ultrastructure of Chlorarachnion reptans (Chlorarchniophyta Divisio nova, Chlorachniophyceae Classis nova . Journal of Phycology 1984, Volume 20 (2), pages 310-330. Doi : 10.1111 / j.0022-3646.1984 .00310.x
Web links
- Chlorarachniophyta on TOLweb
- Chlorarachniophyta on algaebase.org