Mould (Slime) Myxogastria or Mycetozoa
Class: Myxogastria also called Mycetozoa
The term slime mould embraces a heterogeneous assemblage of organisms found worldwide and typically thrive in dark, cool, moist conditions such as prevail on forest floors.
The class Myxomycetes (Myxogastria) are a group of slime moulds that are distributed worldwide, and contain 5 orders, 14 families, 62 genera and about 900 species have been described.
They are colloquially known as the plasmodial or acellular slime moulds and they usually occur in decaying plant material. They exhibit characteristics of both protozoans (one-celled micro organisms) and fungi. All species pass through several, very different morphologic phases, such as microscopic individual cells, slimy amorphous organisms visible with the naked eye and conspicuously shaped fruit bodies. Although they are monocellular, they can reach immense widths and weights: in extreme cases they can be up to 1 metre across and weigh up to 20 kilograms.
The vegetative (active, growing, feeding) phase consists of a multinucleate amoeboid mass or sheet (plasmodium). This gives rise to fruiting structures (sporangia) with one to many spores at the head of a stalk. In nearly all species, spores are borne within the sporangium.
Upon germination, a spore releases one or more individual cells known as myxamoebae, which may transform into so-called swarm cells with two flagella (whip like structures used in swimming). The swarm cells often revert to the amoeboid stage. Formerly, it was believed that reproduction involved the nonsexual fusion of swarm cells, but the process is now thought to be sexual.
The plasmodium, with cytoplasm streaming through it, changes shape as it crawls over or within damp wood, leaves, or soil, ingesting bacteria, moulds, and fungi. Characteristically, the entire plasmodium is covered by a layer of slime, which is continually secreted and, as the plasmodium creeps, continually left behind as a network of collapsed tubules. Plasmodia are frequently yellow and orange, but they may also be colourless, red, white, buff, maroon, or, rarely, blue, black, or green.
Photo of the accumulations of fruiting bodies of unknown Myxomycetes slime mould.
An imature slime mould.
Photo below in a fruiting body of a slime mould.on decaying wood.
For more photos of types of slime moulds visit: