Uno Eliasson

Myxomycetes, acellular slime moulds


Myxomycetes or so-called acellular slime molds are a group of organisms with worldwide distribution. Long ago they were referred to the animal kingdom due to the occurrence in their life cycle of a free-living stage with motile cells. They were later grouped with the fungi. Today myxomycetes together with dictyostelids (cellular slime moulds) and protostelids are referred to a separate kingdom, that has been demonstrated to be monophyletic. The assimilating stage of myxomycetes is a multinuclear protoplast, a plasmodium, which cytologically is one single cell. In some species it becomes several centimetres in diameter. In many species it is strongly pigmented. The plasmodium is motile and moves through a special technique based on protoplasma streaming. The organisms are heterotrophic, feeding on fungal spores, yeast cells, microscopic algae, or various small organic fragments. They are often found on decaying wood and in the litter layer in forests, but many species grow within decaying wood, emerging onto the surface to fructify. There are strong indications that myxomycetes in their amoeboidal stage may play an important ecological role in soil.

The plasmodium transforms into one or several fruitbodies. Fruitbodies are of different shapes dependent on species. They may be several cm across or microscopic. The largest fruitbodies are found in Brefeldia maxima and Fuligo septica which may reach 40 – 50 cm in extent. The smallest fruitbodies, not exceeding 25 µm in height, are those of Echinostelium bisporum. One single plasmodium may in some species give rise to several hundred genetically identical fruitbodies.

Although myxomycetes are found all over the world they seem to be most abundant in temperate regions. Some species are adapted to very special ecological niches, for example developing fruitbodies in the immediate vicinity of melting snow or under a snow layer. Dispersal by wind is important but insects and other arthropods appear to be the principal dispersal agents for many species. Some insects have their larval development in plasmodia and/or fruitbodies of certain myxomycetes. Roughly 800 species are known in the world.

My own research on myxomycetes is focused on taxonomy and distribution. I am responsible for the myxomycete volume in the Swedish Taxonomy Initiative project and am a member of the Hawaii Biodiversity Inventory project as an expert on myxomycetes.

Selected relevant references. For additional references see complete publication list >>

Lado, C. & Eliasson, U.: Taxonomy and Systematics: Current knowledge and approaches on the taxonomic treatment of Myxomycetes. In Stephenson, S. & Rojas, C. (eds), Myxomycetes: Biology, Systematics, Biogeography, and Ecology, pp. 205-251. Elsevier (2017).

Eliasson, U.: Svenska slemsvampar. – Forskningsrapport från Svenska Artprojektet. March 2016. 3 pp.

Eliasson, U. H.: Review and remarks on current generic delimitations in the myxomycetes, with special emphasis on Licea, Listerella and Perichaena. - Nova Hedwigia 104: 343-350 (2017). (Published on line in April 2015; DOI:10.1127/nova_hedwigia/2015/0283).

Eliasson, U.: Coprophilous myxomycetes: Recent advances and future research directions. - Fungal Diversity 59:
85-90. (Published on line in Oct. 2012; DOI 10.1007/s13225-012-0185-6).

Eliasson, U.: Myxomyceter (Myxogastria) – allmänt om biologi, artbegrepp och inbördes fylogenetiska samband samt kort historik över inventering av arter I Sverige. (Myxogastria; biology, species concept and interrelationships, with a brief history of the inventory of species in Sweden.) – Svensk Mykologisk Tidskrift 33: 50-61 (2012). (In Swedish with abstract in English.)

Eliasson, U.: Slemsvampar (Mycetozoa), en allmän översikt. (A general survey of slime moulds.) – Svensk Mykologisk Tidskrift 33: 9-15 (2012). (In Swedish with abstract in English.)

Eliasson, U.: Progress and challenges in the taxonomic research on Myxomycetes. - Inaugural Lecture at the 7th International Congress on Systematics and Ecology of Myxomycetes (ICSEM7). Recife, Brazil. Abstracts volume, pp 20-34 (2011).

Eliasson, U.: Generic delimitations in Myxomycetes. - ICSEM7 Abstracts volume: 65 (2011).

Eliasson, U.: Fimicolous Myxomycetes. - ICSEM7 Abstracts volume: 67 (2011).

Eliasson, U. H., Sjögren, L., Castillo, A. & Moreno, G.: Two species of the Stemonitales (Myxomycetes) new to Sweden with remarks on generic delimitations. - Boletin Sociedad Micologica de Madrid 34: 147-154 (2010).

Adamonyte, G. & Eliasson, U. H.: Morphological variation and taxonomic characters in Cribraria (Myxomycetes) from the Great Smoky Mountains National Park in eastern USA. – Nova Hedwigia 90: 303-320 (2010).

Leontyev, D. V., Eliasson, U., Kochergina, A. V. & Morozova, I. I.: New and rare myxomycetes of Ukraine. 1. East Forest-Steppe. – Karstenia 49: 61-67 (2009).

Eliasson, U. H. & Adamonyte, G.: Species of myxomycetes new to Sweden with additional records of some rarely collected species. – Karstenia 49: 33-39 (2009)

Leontyev, D. V., Eliasson, U., Kochergina, A. V. & Morozova, I. I.: New Myxomycete records from Nature Reserves of Ukraine. - Abstracts of 6th International Congress on Systematics and Ecology of Myxomycetes (ICSEM6), p. 43. Nikita Botanic Garden, Yalta, Crimea, Ukraine, (2008).

Eliasson, U. H. & Gilert, E.: Additions to the Swedish myxomycete biota. - Karstenia 47: 29-36 (2007).

Eliasson, U. H.: Myxomycetes within the Swedish Taxonomy Initiative Project. - Fifth International Congress on the Systematics and Ecology of Myxomycetes (ICSEM5). Tlaxcala, Mexico. Abstracts volume, pp. 27-28 (2005).

Eliasson, U.: A critical review of myxomycete records from the Hawaiian Islands. – Systematics and Geography of Plants 74: 81-86 (2004).

Keller, H. W., Skrabal, M., Eliasson, U. H. & Gaither, T. W.: Tree canopy biodiversity in the Great Smoky Mountains National Park: ecological and developmental studies of a new myxomycete species of Diachea. –Mycologia 96: 537-547 (2004).

Eliasson, U. H.: Myxomycetes of Hawaii. – ICSEM4, Abstracts volume, p. 23 (2002).

Eliasson, U. H.: Observations on the genus Amaurochaete (Myxomycetes), and a European record of A. trechispora. - Karstenia 40: 31–38 (2000).

Eliasson, U. H.: Myxomyceten auf lebenden Blättern im tropischen Regenwald Ecuadors; eine Untersuchung basierend auf dem Herbarmaterial höherer Pflanzen. - Stapfia 73: 81–84 (2000).

Eliasson, U. H. & Keller, H. W. 1999: Coprophilous myxomycetes: updated summary, key to species, and taxonomic observations on Trichia brunnea, Arcyria elaterensis, and Arcyria stipata. - Karstenia 39: 1–10 (1999).

Eliasson, U. H. & Keller, H. W.: The genus Clastoderma: taxonomic evaluation and infraspecific variation of C. debaryanum. - Mycological Research 100: 601—609 (1996).

Keller, H. W. & Eliasson, U. H.: Taxonomic evaluation of Perichaena depressa and P. quadrata (Myxomycetes) based on controlled cultivation, with additional observations on the genus. - Mycological Research 96: 1085—1097 (1992).

Eliasson, U. H., Keller, H. W. & Schoknecht, J. D.: Kelleromyxa, a new generic name for Licea fimicola (Myxomycetes). - Mycological Research 95: 1201—1207 (1991).

Eliasson, U. H.: The myxomycete biota of the Hawaiian Islands. – Mycological Research 95: 257—267 (1991).

Keller, H. W., Eliasson, U. H., Braun, K. L. & Buben-Zurey, M. J.: Corticolous Myxomycetes X: Ultrastructure and taxonomic status of Cribraria minutissima and C. confusa. – Mycologia 80: 536—545 (1988).

Eliasson, U. H., Keller, H. W. & Hutchison, J. A.: Myxomycetes from Arkansas. – Mycotaxon 32: 375—398 (1988).

Eliasson, U. & Nannenga-Bremekamp, N. E.: Myxomycetes of the Scalesia forest, Galápagos Islands. - Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen, Ser. C, 86: 143—153 (1983).

Eliasson, U. & Gilert, E.: A SEM-study of Listerella paradoxa (Myxomycetes). – Nordic Journal of Botany 2: 249—255 (1982).

Eliasson, U.: Ultrastructure of peridium and spores in Lycogala and Reticularia (Myxomycetes). - Transactions of the British Mycological Society 77: 243—249 (1981).

Eliasson, U.: Patterns of occurrence of myxomycetes in a spruce forest in south Sweden. – Holarctic Ecology 4: 20—31 (1981).

Eliasson, U. & Lundqvist, N.: Fimicolous myxomycetes. - Botaniska Notiser 132: 551—568 (1979).

Eliasson, U.: Något om myxomyceternas struktur, biologi och släktskap med andra organismer. /On the structure and biology of myxomycetes, and their relationships with other organisms./ (In Swedish with English abstract.) - Svensk Botanisk Tidskrift 72: 33—49 (1978).

Eliasson, U.: Recent advances in the taxonomy of Myxomycetes. - Botaniska Notiser 130: 483—492 (1977).

Eliasson, U.: Ecological notes on Amaurochaete Rost. (Myxomycetes). - Botaniska Notiser 129: 419—425 (1977).

Eliasson, U.: Myxomyceter (slemsvampar) i Göteborgs Botaniska Trädgårds Naturpark. /Myxomycetes in the Nature Reserve of the Gothenburg Botanical Garden. Popular account with keys, descriptions of species, life cycles, ecology etc./ (In Swedish). 76 pp. + 8 colour plates. Falköping (1976).