Hypothallus

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Fruiting body of a slime mold, probably Tubifera ferruginosa . The hypothallus is clearly recognizable as a spongy, white base.

The real slime mold, the myxogastria , is a hypothallus , a skin-like layer on which the fruiting body rests and which is the connection between the fruiting body and the subsurface. The term literally means "under the thallus ".

The hypothallus is formed by the plasmodium at the beginning of fructification. Depending on the type, it can be membranous to thick or delicate to firm and almost transparent to brightly colored. It is either delimited as a base of individual fruit bodies or as a continuous layer that connects the bases of numerous fruit bodies with one another. In rare cases it is completely absent.

Depending on the taxon , it is directly involved in the further development of the fruiting body: in the Stemonitida there is a so-called "epihypothallic" development of fructification. Here, a hollow, tubular stem (and as a result also a columella ) is developed from the hypothallus ; this triad forms a morphological unit. The remaining plasmodium rises on the stem or the columella and forms a separate structure that carries the spores .

In all other Myxogastria, however, a “sub-hypothallic” development takes place. The hypothallus forms a layer on top of the plasmodium, which forms the spaces of the individual fruiting bodies during fruit formation. Since the surrounding plasmodium then flows into the fruiting body, the hypothallus comes to lie directly on the substrate, shrinks and thus forms the base of the ripe fruiting body. The hypothallus is here with the peridium and the stem part of a morphological unit that serves as the membranous outer skin of the entire spore- bearing structure.

The epihypothallia is an autapomorphy of the Stemonitida and is considered a primitive feature compared to the sub-hypothallia.

proof

  1. ^ Reference for the paragraph: Henry Stempen, Steven L. Stevenson: Myxomycetes. A Handbook of Slime Molds . Timber Press, 1994, ISBN 0-88192-439-3 , pp. 26 .
  2. ↑ Wolfgang Nowotny: Myxomycetes (slime molds) and Mycetozoa (mushroom animals) - life forms between animals and plants. In: Wolfgang Nowotny (Ed.): Wolfsblut and Lohblüte. Life forms between animals and plants = Myxomycetes (=  Stapfia . Band 73 ). Linz 2000, ISBN 3-85474-056-5 , p. 7–37 (German, English, French, Spanish). PDF on ZOBODAT
  3. ↑ Documentation for the paragraph: A.-M. Fiore-Donno, C. Berney, J. Pawlowski, SL Baldauf: Higher-Order Phylogeny of Plasmodial Slime Molds (Myxogastria) Based on Elongation Factor 1-A and Small Subunit rRNA Gene Sequences. In: Journal of Eukaryotic Microbiology, 52, pp. 201-210, 2005.
  4. ↑ Proof for the paragraph: Wolfgang Nowotny: Myxomyceten (Schleimpilze) and Mycetozoa (mushroom animals) - life forms between animal and plant In: Wolfgang Nowotny (Ed.): Wolfsblut und Lohblüte. Life forms between animals and plants = Myxomycetes (=  Stapfia . Band 73 ). Linz 2000, ISBN 3-85474-056-5 , p. 7–37 (German, English, French, Spanish). PDF on ZOBODAT
  5. ↑ A.-M. Fiore-Donno, C. Berney, J. Pawlowski, SL Baldauf: Higher-Order Phylogeny of Plasmodial Slime Molds (Myxogastria) Based on Elongation Factor 1-A and Small Subunit rRNA Gene Sequences. In: Journal of Eukaryotic Microbiology, 52, pp. 201-210, 2005