Plasmodium (slime mold)
In slime molds , the Plasmodium is a large, pithy , membrane-enclosed protoplasm mass that feeds on phagocytosis . In the myxomycetes , the mononuclear amoeboid cell of the first phase produces a multinucleated plasmodium through multiple nuclear divisions . It represents the most important phase of the trophic stage in the life cycle of the (real) slime mold. Under favorable circumstances the plasmodium matures, forms fructifications and changes into a spore-forming fruiting body . The spores contained in this fruiting body, the sporocarp , are spread with the wind after it disintegrates. From these germinating, unicellular amoeboid organisms can develop - a myxamoeba or, in a wet environment, a myxoflagellate , initially with only one cell nucleus.
The following types of plasmodia are common:
- Protoplasmodium : It is only visible with a microscope and is inconspicuous. It is common in basal forms of the myxogastria, the Echinosteliida .
- Aphanoplasmodium : A fine network is formed that covers larger areas. Representatives of this type are the Stemonitidae .
- Phaneroplasmodium : It is visible to the naked eye and is clearly differentiated both morphologically and functionally. He is thus the most highly developed type. The Physarida and the Liceida form phaneroplasmodia.
A so-called pseudoplasmodium is formed in the subclass of Dictyostelia . This is caused by the myxamoeba crawling together without cell walls. However, each cell still retains its independence. It is also called aggregation plasmodium.
- ^ Henry Stempen, Steven L. Stevenson: Myxomycetes. A Handbook of Slime Molds . Timber Press, 1994, ISBN 0-88192-439-3 , pp. 161 ff .
- ↑ a b H. O. Schwantes: Biology of mushrooms . Stuttgart 1996, ISBN 3-8252-1871-6 , pp. 308-311.
- ↑ a b c Michael J. Dykstra, Harold W. Keller: Mycetozoa In: John J. Lee, GF Leedale, P. Bradbury (Eds.): An Illustrated Guide to the Protozoa . tape 2 . Allen, Lawrence 2000, ISBN 1-891276-23-9 , pp. 960-961 .