Paramoebidium

{{Short description|Genus of eukaryotes}} {{Automatic_taxobox | image = Amoebidiales (10.3897-mycokeys.67.52055) Figures 26–30.jpg | image_caption = | taxon = Paramoebidium | authority = Léger & Duboscq, 1929<ref name=":0">Léger, L., and Duboscq, O. 1929. L'évolution des ''Paramoebidium'', nouveau genre d'Eccrinides, parasite des larves aquatiques d'Insectes. ''Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences Paris'' '''189''': 75-77.</ref> | type_species = ''Paramoebidium inflexum'' | type_species_authority = [[Urbain-Louis-Eugène Léger|Léger]] & [[Octave Duboscq|Duboscq]], 1929 | subdivision_ranks = Species | subdivision = }}

'''''Paramoebidium''''' is a genus of unicellular, symbiotic [[eukaryote]]s that inhabit the digestive tract of immature freshwater [[arthropod]] hosts (e.g. [[black fly]] larvae, [[mayfly]] and [[Plecoptera|stonefly]] nymphs).<ref name=":1">Lichtwardt, R.W., M.J. Cafaro, M.M. White. 2001. The Trichomycetes: Fungal Associates of Arthropods Revised Edition. Published online http://www.nhm.ku.edu/%7Efungi/Monograph/Text/Mono.htm {{Webarchive|url=https://web.archive.org/web/20170426185213/http://www.nhm.ku.edu/~fungi/Monograph/Text/Mono.htm |date=2017-04-26 }}</ref> ''Paramoebidium'' is classified in the [[opisthokont]] class [[Mesomycetozoea]]<ref>Mendoza L, Taylor JW, Ajello L (October 2002). [http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.micro.56.012302.160950?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dncbi.nlm.nih.gov "The class mesomycetozoea: a heterogeneous group of microorganisms at the animal-fungal boundary"]. ''Annu. Rev. Microbiol''. '''56''': 315–44. [[Digital object identifier|doi]]:10.1146/annurev.micro.56.012302.160950</ref> (= Ichthyosporea<ref>Cavalier-Smith, T. 1998. Neomonada and the origin of animals and fungi. In: Coombs GH, Vickerman K, Sleigh MA, Warren A (ed.) ''Evolutionary relationships among protozoa.'' Kluwer, London, pp. 375-407.</ref>), and is the sole genus in the family Paramoebidiidae.<ref>Reynolds, N.K., M.E. Smith, E.D. Tretter, J. Gause, D. Heeney, M.J. Cafaro, J.F. Smith, S.J. Novak, W.A. Bourland, M.M. White. 2017. Resolving relationships at the animal-fungal divergence: A molecular phylogenetic study of the protist trichomycetes (Ichthyosporea, Eccrinida). Molecular Phylogenetics and Evolution in press, available online 20Feb.2017. https://dx.doi.org/10.1016/j.ympev.2017.02.007</ref> Prior to 2005,<ref>Cafaro, M. 2005. Eccrinales (Trichomycetes) are not fungi, but a clade of protists at the early divergence of animals and fungi. Molecular Phylogenetics and Evolution 35: 21-34.</ref> ''Paramoebidium'' species were tentatively placed with the fungal group [[Trichomycetes]] due to their habitation of arthropod guts, host overlap between various ''Paramoebidium'' and fungal trichomycete taxa, and similar vegetative growth form.<ref name=":2">Moss, S.T., 1979. Commensalism of Trichomycetes. In L. R. Batra, ed. ''Insect-Fungus Symbiosis Nutrition, Mutualism, and Commensalism''. Montclair: Allanheld, Osmun & Co. Publishers, Inc., pp. 175–227.</ref>

== Etymology == The prefix "para-", roughly meaning "similar to", refers to the assumed relatedness of ''Paramoebidium'' to the genus ''[[Amoebidium]]''.<ref name=":0" /> Members of both genera may produce motile, amoeba-like dispersal cells during their life cycle.<ref name=":2" /> The similarity of life cycle, morphology, and ecology lead to the hypothesis that ''Amoebidium'' and ''Paramoebidium'' were minimally closely related, and probably [[Sister group|sister taxa]].<ref name=":1" />

== Description == ''Paramoebidium'' species are unicellular. The vegetative cells (= [[Thallus|thalli]]) have an elongate, hair-like growth form with a secreted, glue-like holdfast at the base that attaches them to the host digestive tract lining.<ref name=":1" /> Sexual reproduction is unknown. During asexual reproduction, the entire content of the cell is partitioned into many motile amoeboid cells. The cell wall breaks down and the amoeboid cells are released. These amoeboid cells are termed "dispersal amoebae" because they crawl for a short time before encysting. The cyst expands and forms several spores (called [[cystospore]]s) that are released when mature.<ref name=":0" />

== Species == There are currently 17 validly described species of ''Paramoebidium''.<ref name=":1" /> Several other species were described but are considered invalid due to a lack of descriptive detail and/or illustrations.<ref name=":1" /><ref>Duboscq, O., Léger, L., and Tuzet, O. 1948. Contribution à la connaissance des Eccrinides: les Trichomycètes. ''Archives de Zoologie Expérimentale et Générale '''''86''': 29-144.</ref> Species have been described based on the morphological features of the thalli, cysts, and cystospores. Host type is also reported for species, but it is unclear how host specific different ''Paramoebidum'' species may be.<ref name=":1" /> Thallus shapes range from straight, short, and fat to long and sigmoidal, to branched or coiled. For example, ''[https://web.archive.org/web/20170426185213/http://www.nhm.ku.edu/~fungi/Monograph/Text/Mono.htm P. curvum]''<ref>Dang, S., and Lichtwardt, R. W. 1979. Fine structure of ''Paramoebidium'' (Trichomycetes) and a new species with viruslike particles. ''American Journal of Botany'' '''66''': 1093-1104.</ref> have short, coiled, thick thalli and are found in black fly larvae ([[Black fly|Simuliidae]]), whereas ''[https://web.archive.org/web/20170426185213/http://www.nhm.ku.edu/~fungi/Monograph/Text/Mono.htm P. hamatum]''<ref>Bench, M.E., M.M. White. 2012. New species and first records of trichomycetes from immature aquatic insects in Idaho. Mycologia 104(1): 295-312.</ref> have relatively long thalli that are consistently curved near the base giving them a "candy cane" appearance and are associated mainly with mayfly nymphs (Ameletidae and [[Baetidae]]) but also [[Chironomidae|midge]] larvae. However, while ''Paramoebidium'' species are relatively common among trichomycete collections,<ref>Lichtwardt, R. W., and Williams, M. C. 1992a. Two new Australasian species of Amoebidiales associated with aquatic insect larvae, and comments on their biogeography. ''Mycologia'' '''84''': 376-383.</ref><ref name=":1" /> description of new species is problematic due to the amount of intra- and interspecific variability of the morphological characters.<ref>Valle, L.G. 2014. New species of ''Paramoebidium'' (trichomycetes, Mesomycetozoea) from the Mediterranean, with comments about the amoeboid cells in Amoebidiales. Mycologia 106(3): 481-490.</ref> Furthermore, no species have been obtained in axenic culture, so observations are limited to the individuals present at the time of host dissections and some stages of the life cycle (e.g. dispersal amoebae) may not be present in the collection.

List of species:<ref>{{Cite web|url=http://www.mycobank.org/BioloMICS.aspx?TableKey=14682616000000067&Rec=96954&Fields=All |title=Paramoebidium |website=www.mycobank.org|access-date=2020-05-17}}</ref><ref>{{Cite web |url=http://www.speciesfungorum.org/Names/names.asp?strGenus=Paramoebidium |title=Paramoebidium |website=www.speciesfungorum.org|access-date=2020-05-17}}</ref> * ''Paramoebidium angulatum'' Valle 2014 * ''Paramoebidium arcuatum'' Léger & Duboscq ex Duboscq, Léger & Tuzet 1948 * ''Paramoebidium argentinense'' Mazzucch., López-Lastra & Lichtwardt 2000 * ''Paramoebidium avitruviense'' Valle 2014 * ''Paramoebidium bacillare'' Strongman, Juan Wang & Xu 2010 * ''Paramoebidium bibrachium'' Williams & Lichtwardt 1990 * ''Paramoebidium cassidula'' Strongman & White 2006 * ''Paramoebidium chattonii'' Léger & Duboscq 1929 ex Duboscq, Léger & Tuzet 1948 * ''Paramoebidium contortum'' Valle & Busquets 2018 * ''Paramoebidium corpulentum'' Lichtwardt & Williams 1991 * ''Paramoebidium curvum'' Lichtwardt 1979 * ''Paramoebidium digitoideum'' Ferrington, Lichtwardt & López-Lastra 1999 * ''Paramoebidium dispersum'' Léger & Duboscq ex Duboscq, Léger & Tuzet 1948 * ''Paramoebidium eccriniforme'' Léger & Duboscq ex Duboscq, Léger & Tuzet 1948 * ''Paramoebidium ecdyonuridae'' Valle 2014 * ''Paramoebidium fuscum'' Duboscq, Léger & Tuzet 1948 * ''Paramoebidium geniculatum'' Duboscq, Léger & Tuzet 1948 * ''Paramoebidium giganteum'' Duboscq, Léger & Tuzet 1948 * ''Paramoebidium grande'' Lichtwardt & Arenas 1996 * ''Paramoebidium hamatum'' White 2012 * ''Paramoebidium inflexum'' Léger & Duboscq 1929 * ''Paramoebidium laterale'' Busquets & Valle 2018 * ''Paramoebidium papillatum'' Lichtwardt & Williams 1992 * ''Paramoebidium pavillardii'' Manier 1951 * ''Paramoebidium pinguiculum'' Strongman & White 2019 * ''Paramoebidium procloeoni'' Manier 1951 * ''Paramoebidium santanderensis'' Baron & Guardia Valle 2018 * ''Paramoebidium simulii'' Tuzet & Manier 1955 * ''Paramoebidium stipula'' Strongman & White 2006 * ''Paramoebidium thrauli'' Léger & Duboscq ex Duboscq, Léger & Tuzet 1948 * ''Paramoebidium torpediniforme'' Strongman & White 2019 * ''Paramoebidium umbonatum'' Strongman & White 2008

==References== {{Reflist}}

[[Category:Ichthyosporea]] [[Category:Eukaryote genera]]