| Myxogastria | |
|---|---|
| Diderma testaceum | |
| Scientific classification | |
| Kingdom: | Amoebozoa |
| Phylum: | Mycetozoa |
| Class: | Myxogastria |
| Orders | |
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Myxogastria (formely known as Myxomycota) is a class of Mycetozoa,[1][2] itself a grouping of slime molds, that contains 5 orders, 14 families, 62 genera, and 888 species.[3] Notable examples within Myxogastria include the genus Stemonitis and the species Physarum polycephalum.[4] Myxogastria are also referred to as myxogastrids.[5]
They are heterotrophic organisms which prey on microbial food webs, and so they are able to engulf and digest bacteria, yeast, fungal spores, and decaying matter.[6]
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The group formerly known as Myxomycota, now known not to be fungal, is now usually classified under Myxogastria. Myxomycota are also referred to as myxomycetes.
The Latin name Myxomycota comes from the Greek words μύξα (myxa), which means "mucus", and μύκης (myces), which means "fungus". They are colloquially known as plasmodial or acellular slime molds. Some would also consider Myxomycota as a higher systematic group (i.e. kingdom) unto itself, with an unsettled phylogeny because of conflicting molecular and developmental data. The relations between lower systematic groups (in this case orders) are as yet unclear.[7]
When a myxomycete spore germinates, it cracks, releasing an amoeboid cell called a myxamoeba. Depending upon environmental conditions, the myxamoeba can produce flagella, in which case it is known as a swarm cell. This process is reversible and the flagellum can be retracted so the myxamoeba is established again. The latter ingests food via phagocytosis and divides as it eats. When two myxamoebae of different mating types find each other, they will merge, forming a zygote. The zygote itself will not divide, but rather it will grow as its nucleus divides, forming a large, multinucleate cell called a plasmodium. The plasmodium will continue to consume organic matter through phagocytosis. After some time, for unknown causes, the plasmodium will convert into a spore-bearing structure called a fruiting body. The four major types of fruiting bodies are the sporangium, the aethalium, the psedoaethalium and the plasmodiocarp. Spores are released from the fruiting body and the life cycle starts over.
| Wikisource has the text of The New Student's Reference Work article Myxomycetes. |
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