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The family Acrasidae (ICZN, or Acrasiomycota, ICBN) is a family[1] of slime molds which belongs to the excavate group Percolozoa. The name element acrasio- comes from the Greek akrasia, meaning "acting against one's judgement". This group consists of cellular slime molds.

Acrasid slime molds
Acrasis rosea 31095.jpg
Acrasis rosea
Scientific classification e
(unranked): Discoba
Superphylum: Discicristata
Phylum: Percolozoa
Class: Heterolobosea
Order: Acrasida
Family: Acrasidae
van Tieghem 1880 ex Hartog 1906
  • Acrasiaceae Poche 1913 em. Olive 1970
  • Guttulinaceae Zopf 1885 ex Berlese 1888 nom. rej.
  • Guttulininae Doflein & Reichenow 1952
  • Pocheinaceae Loeblich & Tappan 1961 nom. cons.
Acrasis rosea amoebae and spores under microscope

Some would also consider it as a kingdom unto itself, but the debate is as yet unsettled.

The terms "Acrasiomycota" or "Acrasiomycetes" have been used when the group was classified as a fungus ("-mycota"). In some classifications, Dictyostelium was placed in Acrasiomycetes, an artificial group of cellular slime molds, which was characterized by the aggregation of individual amoebae into a multicellular fruiting body, making it an important factor that related the acrasids to the dictyostelids.[2]


When resources such as water or food become limiting, the amoeba will release pheromones such as acrasin to aggregate amoebal cells in preparation for movement as a large (thousands of cells) grex or pseudopod. When in the grex, the amoeboids reproduce, resulting in fruit-like structures called spores, which develop into unicellular molds of the same species.


  1. ^ Roger AJ, Smith MW, Doolittle RF, Doolittle WF (1996). "Evidence for the Heterolobosea from phylogenetic analysis of genes encoding glyceraldehyde-3-phosphate dehydrogenase" (PDF). J. Eukaryot. Microbiol. 43 (6): 475–85. doi:10.1111/j.1550-7408.1996.tb04507.x. PMID 8976605.
  2. ^ Cavender J.C.; Spiegl F.; Swanson A. (2002). "Taxonomy, slime molds, and the questions we ask". The Mycological Society of America. 94 (6): 968–979. PMID 21156570.
  • C.J. Alexopolous, Charles W. Mims, M. Blackwell et al., Introductory Mycology, 4th ed. (John Wiley and Sons, Hoboken NJ, 2004) ISBN 0-471-52229-5