Euglyphida

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Euglyphida
Euglypha sp.jpg
Euglypha sp.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Clade: Diaphoretickes
Clade: SAR
Phylum: Cercozoa
Class: Imbricatea
Order: Euglyphida
Copeland, 1956
Families [1]

The euglyphids are a prominent group of filose amoebae that produce shells or tests that in most described species is reinforced by siliceous scales, plates, and sometimes spines, but this reinforcement is absent in other species. [2] These elements are created within the cell and then assembled on its surface in a more or less regular arrangement, giving the test a textured appearance. There is a single opening for the long slender pseudopods, which capture food and pull the cell across the substrate.

Contents

Euglyphids are common in soils, marshes, and other organic-rich environments, feeding on tiny organisms such as bacteria. The test is generally 30–100 μm in length, although the cell only occupies part of this space. During reproduction a second shell is formed opposite the opening, so both daughter cells remain protected. Different genera and species are distinguished primarily by the form of the test. Euglypha and Trinema are the most common.

The euglyphids are traditionally grouped with other amoebae. However, genetic studies instead place them with various amoeboid and flagellate groups, forming an assemblage called the Cercozoa. Their closest relatives are the thaumatomonads, flagellates that form similar siliceous tests.

We find photosynthetic species in the genera Paulinella and Placocista. The photosynthetic abilities in Paulinella comes from an event when a cyanobacterium settled permanently within the cell. In Placocista, where a few species have colonies of symbiotic Chlorella living inside them, the relationship is less intimate. The photosynthetic Paulinella are phototrophic, and the photosynthetic Placocista are mixotrophic. [3] [4] [5]

Phylogeny

Phylogeny based on Chatelain et al. 2013 [6]

Euglyphida

Paulinellidae de Saedeleer 1934 emend. Adl et al. 2012

Cyphoderiidae de Saedeleer 1934

Tracheleuglypha Deflandre 1928

Euglyphina

Assulinidae Lara et al. 2007

Euglyphidae Wallich 1864 emend Lara et al. 2007

Sphenoderiidae Chatelain et al. 2013

Trinematidae Hoogenraad & De Groot 1940 emend Adl et al. 2012

Taxonomy

Order EuglyphidaCopeland 1956 emend. Cavalier-Smith 1997 [7]

Related Research Articles

<span class="mw-page-title-main">Cercozoa</span> Group of single-celled organisms

Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eukaryotic group to be recognized mainly through molecular phylogenies. They are the natural predators of many species of bacteria. They are closely related to the phylum Retaria, comprising amoeboids that usually have complex shells, and together form a supergroup called Rhizaria.

<span class="mw-page-title-main">Rhizaria</span> Infrakingdom of protists

The Rhizaria are a diverse and species-rich supergroup of mostly unicellular eukaryotes. Except for the Chlorarachniophytes and three species in the genus Paulinella in the phylum Cercozoa, they are all non-photosynthethic, but many foraminifera and radiolaria have a symbiotic relationship with unicellular algae. A multicellular form, Guttulinopsis vulgaris, a cellular slime mold, has been described. This group was used by Cavalier-Smith in 2002, although the term "Rhizaria" had been long used for clades within the currently recognized taxon. Being described mainly from rDNA sequences, they vary considerably in form, having no clear morphological distinctive characters (synapomorphies), but for the most part they are amoeboids with filose, reticulose, or microtubule-supported pseudopods. In the absence of an apomorphy, the group is ill-defined, and its composition has been very fluid. Some Rhizaria possess mineral exoskeletons, which are in different clades within Rhizaria made out of opal, celestite, or calcite. Certain species can attain sizes of more than a centimeter with some species being able to form cylindrical colonies approximately 1 cm in diameter and greater than 1 m in length. They feed by capturing and engulfing prey with the extensions of their pseudopodia; forms that are symbiotic with unicellular algae contribute significantly to the total primary production of the ocean.

<span class="mw-page-title-main">Tectofilosid</span> Group of protists

The tectofilosids are a group of filose amoebae with shells. These are composed of organic materials and sometimes collected debris, in contrast to the euglyphids, which produce shells from siliceous scales. The shell usually has a single opening, but in Amphitrema and a few other genera it has two on opposite ends. The cell itself occupies most of the shell. They are most often found on marsh plants such as Sphagnum.

<span class="mw-page-title-main">Tubulinea</span> Class of protozoans

The Tubulinea are a major grouping of Amoebozoa, including most of the more familiar amoebae genera like Amoeba, Arcella, Difflugia and Hartmannella.

<span class="mw-page-title-main">Monadofilosa</span> Group of protists

Monadofilosa is a grouping of Cercozoa. These organisms are single-celled amoeboid protists.

<span class="mw-page-title-main">Arcellinida</span> Order of Amoebozoa

Arcellinid testate amoebae or Arcellinida, Arcellacean or lobose testate amoebae are single-celled protists partially enclosed in a simple test (shell).

<i>Paulinella</i> Genus of single-celled organisms

Paulinella is a genus of at least eleven species including both freshwater and marine amoeboids. Like many members of euglyphids it is covered by rows of siliceous scales, and use filose pseudopods to crawl over the substrate of the benthic zone.

<span class="mw-page-title-main">Thecofilosea</span> Class of single-celled organisms

Thecofilosea is a class of unicellular testate amoebae belonging to the phylum Cercozoa. They are amoeboflagellates, organisms with flagella and pseudopodia, distinguished from other cercozoa by their scale-lacking test composed of organic material. They are closely related to the Imbricatea, a group of testate amoebae with tests composed of inorganic silica scales.

<span class="mw-page-title-main">Testate amoebae</span>

Testate amoebae are a polyphyletic group of unicellular amoeboid protists, which differ from naked amoebae in the presence of a test that partially encloses the cell, with an aperture from which the pseudopodia emerge, that provides the amoeba with shelter from predators and environmental conditions.

<span class="mw-page-title-main">Sarcomonadea</span> Class of flagellate protists

The sarcomonads or class Sarcomonadea are a group of amoeboid biciliate protists in the phylum Cercozoa. They are characterized by a propensity to move through gliding on their posterior cilium or through filopodia, a lack of scales or external theca, a soft cell surface without obvious cortical filamentous or membranous skeleton, two cilia without scales or hairs, tubular mitochondrial cristae, near-spherical extrusomes, and a microbody attached to the nucleus.

<span class="mw-page-title-main">Vampyrellida</span> Order of single-celled organisms

The vampyrellids, colloquially known as vampire amoebae, are a group of free-living predatory amoebae classified as part of the lineage Endomyxa. They are distinguished from other groups of amoebae by their irregular cell shape with propensity to fuse and split like plasmodial organisms, and their life cycle with a digestive cyst stage that digests the gathered food. They appear worldwide in marine, brackish, freshwater and soil habitats. They are important predators of an enormous variety of microscopic organisms, from algae to fungi and animals. They are also known as aconchulinid amoebae.

<span class="mw-page-title-main">Taxonomy of Protista</span> Organism classification

A protist is any eukaryotic organism that is not an animal, plant, or fungus. The protists do not form a natural group, or clade, since they exclude certain eukaryotes with whom they share a common ancestor; but, like algae or invertebrates, the grouping is used for convenience. In some systems of biological classification, such as the popular five-kingdom scheme proposed by Robert Whittaker in 1969, the protists make up a kingdom called Protista, composed of "organisms which are unicellular or unicellular-colonial and which form no tissues". In the 21st century, the classification shifted toward a two-kingdom system of protists: Chromista and Protozoa.

<i>Amphitrema</i> Genus of single-celled organisms

Amphitrema is a genus of testate amoeba in the family Amphitremidae. The genus is commonly found in Sphagnum-dominated peatlands. All species of this genus are mixotrophic and harbor unicellular algae belonging to genus Chlorella.

Stercomata are extracellular pellets of waste material produced by some groups of foraminiferans, including xenophyophoreans and komokiaceans, Gromia, and testate amoebae. The pellets are ovoid (egg-shaped), brownish in color, and on average measure from 10-20 µm in length. Stercomata are composed of small mineral grains and undigested waste products held together by strands of glycosaminoglycans.

<span class="mw-page-title-main">Hyalospheniidae</span> Family of testate amoebae

Hyalospheniidae is a group of testate amoebae and the sole family of the infraorder Hyalospheniformes. Hyalospheniid testate amoebae are considered important bioindicators, which is why they are frequently used for environmental monitoring and their fossils are studied to investigate the paleoecology.

<i>Nebela</i> Genus of testate amoebae

Nebela is a diverse genus of testate amoebae of cosmopolitan distribution, belonging to the family Hyalospheniidae. They are "prey agglutinated" or "kleptosquamic" organisms, meaning they take the inorganic plates from their prey to construct their test.

Porosia is a genus of arcellinid testate amoebae belonging to the family Hyalospheniidae. Described in 1942, it used to be a monotypic genus with the sole species P. bigibbosa. However a second species, P. paracarinata, was discovered in 2015.

<i>Planocarina</i> Genus of testate amoebae

Planocarina is a genus of arcellinid testate amoebae belonging to the family Hyalospheniidae. It was created in 2016 to agglutinate a clade of species that were previously assigned to the paraphyletic genus Nebela. All species of Planocarina have a compressed keel surrounding the posterior part of their shell. It is the sister group of Alabasta.

<i>Alabasta</i> Genus of testate amoebae

Alabasta is a genus of arcellinid testate amoebae belonging to the family Hyalospheniidae. It contains species with an elongated test and a strongly curved "pseudostome" with a flare and a notch in narrow view. These species previously belonged to the genus Nebela, but were later found to be a distinct monophyletic group different from Nebela. It is the sister group to Planocarina.

<span class="mw-page-title-main">Euglyphia (protist)</span> Superorder of protists

Euglyphia is a group of imbricate protists in the phylum Cercozoa. They are unicellular eukaryotes characterized by a cell body covered in large imbricate scales, and an apical aperture through which they extend either filose pseudopodia or two cilia of different sizes that are not used for gliding.

References

  1. Euglyphida, WoRMS – World Register of Marine Species, retrieved 7 September 2018
  2. Description of Phaeobola aeris gen. nov., sp. nov (Rhizaria, Cercozoa, Euglyphida) Sheds Light on Euglyphida’s Dark Matter - Digital CSIC
  3. Algal And Cyanobacteria Symbioses
  4. One Alga to Rule them All: Unrelated Mixotrophic Testate Amoebae (Amoebozoa, Rhizaria and Stramenopiles) Share the Same Symbiont (Trebouxiophyceae)
  5. Paulinella, a model for understanding plastid primary endosymbiosis
  6. Chatelain, Auriel P.; Meisterfeld, Ralf; Roussel-Delif, Ludovic; Lara, Enrique (2013), "Sphenoderiidae (fam. nov.), a New Clade of Euglyphid Testate Amoebae Characterized by Small, Round Scales Surrounding the Aperture" (PDF), Protist , 164 (6): 782–792, doi:10.1016/j.protis.2013.08.001, PMID   24152919
  7. Kosakyan, Anush; Gomaa, Fatma; Lara, Enrique; Lahr, Daniel J.G. (2016), "Current and future perspectives on the systematics, taxonomy and nomenclature of testate amoebae", European Journal of Protistology , 164 (6): 782–792, doi:10.1016/j.ejop.2016.02.001, hdl: 11380/1302106 , PMID   27004416