{{Short description|Family of single-celled organisms}} {{Automatic taxobox | image = Museum Histoire Naturelle Geneva Blaschka Clathrulina elegans 21102014.jpg | image_caption = Blaschka glass model of ''Clathrulina elegans'' | parent_authority = Hertwig & Lesser, 1874 emend. Honigberg et al. 1964 | taxon = Clathrulinidae | authority = Claus, 1874 | subdivision_ranks = Genera | subdivision = See text | synonyms = * Cryptaxohelida * Desmothoraca <small>Hertwig & Lesser 1874</small> * Clathrulinida <small>Starobogatov 1980</small> }}
Order '''Desmothoracida''', the '''desmothoracids''', are a group of heliozoan protists, usually sessile and found in freshwater environments. The adult is a spherical cell around 10-20 μm in diameter surrounded by a perforated organic lorica, or shell, with many radial pseudopods projecting through the holes to capture food. These are supported by small bundles of microtubules that arise near a point on the nuclear membrane. Unlike other heliozoans, the microtubules are not in any regular geometric array, there does not appear to be a microtubule organizing center, and there is no distinction between the outer and inner cytoplasm.
Reproduction takes place by the budding-off of small motile cells, usually with two flagella. Later these are lost, and the pseudopods and lorica are formed. Typically, a single lengthened pseudopod will secrete a hollow stalk that attaches the cell to the substrate. The form of the flagella, the tubular cristae within the mitochondria, and other characters have led to the suggestion that the desmothoracids belong among what is now the Cercozoa. This was later confirmed by genetic studies.
As of the year 2000, the order Desmothoracida contained five genera with a total of 10 species.<ref name=mikr>Mikrjukov, K. A. (2000). [http://www.rcin.org.pl/Content/13538/WA488_17724_P1825-T39-nr2_AP.pdf Taxonomy and phylogeny of Heliozoa. 1. The order Desmothoracida Hertwig et Lesser, 1874.] ''Acta Protozoologica'' 39(2) 81-97.</ref>
* Order '''Desmothoracida''' <small>Hartwig & Lesser 1874 emend. Honigberg et al. 1964</small> ** Family '''Clathrulinidae''' <small>Claus 1874</small><ref>{{cite journal | website=Collection of genus-group names in a systematic arrangement | title=Part 1- Virae, Prokarya, Protists, Fungi | url=http://mave.tweakdsl.nl/tn/genera1.html | display-authors=etal | access-date=30 June 2016 | archive-url=https://web.archive.org/web/20160814234049/http://mave.tweakdsl.nl/tn/genera1.html | archive-date=14 August 2016 | url-status=dead }}</ref> *** Genus ''Clathrulina'' <small>Cienkowski 1867</small> [''Podosphaera'' <small>Archer 1868 non Kunze 1823</small>; ''Elaster'' <small>Grimm 1872</small>; ''Eleaster'' <small>(sic) Schmidt 1913</small>; ''Orbulinella'' <small>Entz 1877</small>] **** Species ''Clathrulina elegans'' <small>Cienkowski 1867</small> [''Clathrulina ovalis'' <small>(von Daday 1885) Deflandre, 1926</small>; ''Clathrulina cienkowskii ovalis'' <small>von Daday 1885</small>; ''Clathrulina cienkowskii'' <small>Mereschkowsky 1879</small>; ''Clathrulina stuhlmanni'' <small>Schaudinn 1897</small>; ''Podosphaera haeckeliana'' <small>Archer 1868</small>; ''Elaster greeffi'' <small>Grimm 1872</small>] **** Species ''Clathrulina smaragdea'' <small>(Entz 1877) Mikrjukov 2000</small> [''Orbulinella smaragdea'' <small>Entz 1877</small>; ''Orbulinella salina'' <small>Labbe 1924</small>] *** Genus ''Hedriocystis'' <small>Hertwig & Lesser 1874</small> **** Species ''Hedriocystis pellucida'' <small>Hertwig & Lesser 1874</small> **** Species ''Hedriocystis minor'' <small>Siemensma 1991</small> **** Species ''Hedriocystis zhadani'' <small>Mikrjukov 2000</small> *** Genus ''Penardiophrys'' <small>Mikrjukov 2000</small> **** Species ''Penardiophrys reticulata'' <small>(Penard 1904) Mikrjukov 2000</small> [''Hedriocystis reticulata'' <small>Penard 1904</small>] **** Species ''Penardiophrys spinifera'' <small>(Brown 1918) Mikrjukov 2000</small> [''Hedriocystis spinifera'' <small>Brown 1918</small>] *** Genus ''Cienkowskya'' <small>Schaudinn 1896 non Regel & Rach 1859 non Solms 1867</small> [''Cienkowskia'' <small>Weldon & Hickson 1909 non Rostafinski 1873 non Schweinfurth 1867 non Solms 1867</small>; ''Wagneria'' <small>Cienkowsky 1881 non Robineau-Desvoidy 1830 non Gistl 1848 non Alenitzin 1873 non Lemaire 1857 non Hesse 1912 non Heilprin 1887 non McCook 1895 non Jedlicka 1935 non Denier 1933 non Meladze 1967</small>; ''Monomastigocystis'' de Saedeleer 1930] **** Species ''Cienkowskya mereschkovckii'' <small>(Cienkowsky 1881) Schaudinn 1896</small> [''Wagneria mereschkowskyi'' <small>Cienkowsky 1881</small>] **** Species ''Cienkowskya brachypous'' <small>(De Saedeleer 1930) Mikrjukov 2000</small> [''Monomastigocystis brachypous'' <small>de Saedeleer 1930</small>; ''Hedriocystis brachypous'' <small>(De Saedeleer 1930) Siemensma 1991</small>] *** Genus ''Actinosphaeridium'' Zacharias 1893 [''Actinopshaeridium'' (sic)] **** Species ''Actinosphaeridium pedatus'' <small>Zacharias 1893</small> [''Nuclearia caulescens'' <small>Penard 1903</small>]
==Notes== {{Reflist}}
==References== {{Wikispecies|Desmothoracida}} * {{cite journal | author = Nikolaev, S.I. | title = Genetic relationships between desmothoracid Heliozoa and gymnophryid amoebas as evidenced by comparison of 18S rRNA genes | journal = Doklady Biological Sciences | year = 2003 | volume = 393 | issue = 1–6 | pages = 553–6 | doi = 10.1023/B:DOBS.0000010322.33294.9f | pmid = 14994549 | display-authors = 1 | last2 = Berney | first2 = S. | last3 = Fahrni | first3 = J. | last4 = Mylnikov | first4 = A. P. | last5 = Petrov | first5 = N. B. | last6 = Pawlowski | first6 = J. | s2cid = 21189865 }}
{{Rhizaria}} {{Taxonbar|from1=Q151237|from2=Q33181010}}
Category:Filosa Category:Amoebas