Order Desmothoracida, the desmothoracids, are a group of heliozoanprotists, 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.[1]
Order Desmothoracida Hartwig & Lesser 1874 emend. Honigberg et al. 1964
Species Penardiophrys spinifera (Brown 1918) Mikrjukov 2000 [Hedriocystis spinifera Brown 1918]
Genus Cienkowskya Schaudinn 1896 non Regel & Rach 1859 non Solms 1867 [Cienkowskia Weldon & Hickson 1909 non Rostafinski 1873 non Schweinfurth 1867 non Solms 1867; Wagneria 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; Monomastigocystis de Saedeleer 1930]
Species Cienkowskya brachypous (De Saedeleer 1930) Mikrjukov 2000 [Monomastigocystis brachypous de Saedeleer 1930; Hedriocystis brachypous (De Saedeleer 1930) Siemensma 1991]
Genus Actinosphaeridium Zacharias 1893 [Actinopshaeridium (sic)]
Species Actinosphaeridium pedatus Zacharias 1893 [Nuclearia caulescens Penard 1903]
Notesedit
^Mikrjukov, K. A. (2000). Taxonomy and phylogeny of Heliozoa. 1. The order Desmothoracida Hertwig et Lesser, 1874. Acta Protozoologica 39(2) 81-97.
^. Collection of genus-group names in a systematic arrangement. Archived from the original on 14 August 2016. Retrieved 30 June 2016.
Referencesedit
Wikispecies has information related to Desmothoracida.
Nikolaev, S.I.; et al. (2003). "Genetic relationships between desmothoracid Heliozoa and gymnophryid amoebas as evidenced by comparison of 18S rRNA genes". Doklady Biological Sciences. 393 (1–6): 553–6. doi:10.1023/B:DOBS.0000010322.33294.9f. PMID 14994549. S2CID 21189865.
March 14, 2024
desmothoracid, order, desmothoracids, group, heliozoan, protists, usually, sessile, found, freshwater, environments, adult, spherical, cell, around, diameter, surrounded, perforated, organic, lorica, shell, with, many, radial, pseudopods, projecting, through, . 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 mm 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 DesmothoracidBlaschka glass model of Clathrulina elegansScientific classificationDomain EukaryotaClade DiaphoretickesClade SARPhylum CercozoaClass GranofiloseaOrder DesmothoracidaHertwig amp Lesser 1874 emend Honigberg et al 1964Family ClathrulinidaeClaus 1874GeneraSee textSynonymsCryptaxohelida Desmothoraca Hertwig amp Lesser 1874 Clathrulinida Starobogatov 1980Reproduction 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 1 Order Desmothoracida Hartwig amp Lesser 1874 emend Honigberg et al 1964 Family Clathrulinidae Claus 1874 2 Genus Clathrulina Cienkowski 1867 Podosphaera Archer 1868 non Kunze 1823 Elaster Grimm 1872 Eleaster sic Schmidt 1913 Orbulinella Entz 1877 Species Clathrulina elegans Cienkowski 1867 Clathrulina ovalis von Daday 1885 Deflandre 1926 Clathrulina cienkowskii ovalis von Daday 1885 Clathrulina cienkowskii Mereschkowsky 1879 Clathrulina stuhlmanni Schaudinn 1897 Podosphaera haeckeliana Archer 1868 Elaster greeffi Grimm 1872 Species Clathrulina smaragdea Entz 1877 Mikrjukov 2000 Orbulinella smaragdea Entz 1877 Orbulinella salina Labbe 1924 Genus Hedriocystis Hertwig amp Lesser 1874 Species Hedriocystis pellucida Hertwig amp Lesser 1874 Species Hedriocystis minor Siemensma 1991 Species Hedriocystis zhadani Mikrjukov 2000 Genus Penardiophrys Mikrjukov 2000 Species Penardiophrys reticulata Penard 1904 Mikrjukov 2000 Hedriocystis reticulata Penard 1904 Species Penardiophrys spinifera Brown 1918 Mikrjukov 2000 Hedriocystis spinifera Brown 1918 Genus Cienkowskya Schaudinn 1896 non Regel amp Rach 1859 non Solms 1867 Cienkowskia Weldon amp Hickson 1909 non Rostafinski 1873 non Schweinfurth 1867 non Solms 1867 Wagneria 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 Monomastigocystis de Saedeleer 1930 Species Cienkowskya mereschkovckii Cienkowsky 1881 Schaudinn 1896 Wagneria mereschkowskyi Cienkowsky 1881 Species Cienkowskya brachypous De Saedeleer 1930 Mikrjukov 2000 Monomastigocystis brachypous de Saedeleer 1930 Hedriocystis brachypous De Saedeleer 1930 Siemensma 1991 Genus Actinosphaeridium Zacharias 1893 Actinopshaeridium sic Species Actinosphaeridium pedatus Zacharias 1893 Nuclearia caulescens Penard 1903 Notes edit Mikrjukov K A 2000 Taxonomy and phylogeny of Heliozoa 1 The order Desmothoracida Hertwig et Lesser 1874 Acta Protozoologica 39 2 81 97 Part 1 Virae Prokarya Protists Fungi Collection of genus group names in a systematic arrangement Archived from the original on 14 August 2016 Retrieved 30 June 2016 References edit nbsp Wikispecies has information related to Desmothoracida Nikolaev S I et al 2003 Genetic relationships between desmothoracid Heliozoa and gymnophryid amoebas as evidenced by comparison of 18S rRNA genes Doklady Biological Sciences 393 1 6 553 6 doi 10 1023 B DOBS 0000010322 33294 9f PMID 14994549 S2CID 21189865 Retrieved from https en wikipedia org w index php title Desmothoracid amp oldid 1193291133, wikipedia, wiki, book, books, library,
