Lobosa is a taxonomic group of amoebae in the phylum Amoebozoa. Most lobosans possess broad, bluntly rounded pseudopods, although one genus in the group, the recently discovered Sapocribrum, has slender and threadlike (filose) pseudopodia. In current classification schemes, Lobosa is a subphylum, composed mainly of amoebae that have lobose pseudopods but lack cilia or flagella.
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. 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.
The Amoebidae are a family of Amoebozoa, including naked amoebae that produce multiple pseudopodia of indeterminate length. These are roughly cylindrical with granular endoplasm and no subpseudopodia, as found in other members of the class Tubulinea. During locomotion one pseudopod typically becomes dominant and the others are retracted as the body flows into it. In some cases the cell moves by "walking", with relatively permanent pseudopodia serving as limbs.
Difflugia is the largest genus of Arcellinida, one of several groups of Tubulinea within the eukaryote supergroup Amoebozoa. Arcellinida species produce shells or tests from mineral particles or biogenic elements and are thus commonly referred to as testate amoebae or shelled amoebae. Difflugia are particularly common in marshes and other freshwater habitats.
The Tubulinea are a major grouping of Amoebozoa, including most of the more familiar amoebae genera like Amoeba, Arcella, Difflugia and Hartmannella.
Discosea is a class of Amoebozoa, consisting of naked amoebae with a flattened, discoid body shape. Members of the group do not produce tubular or subcylindrical pseudopodia, like amoebae of the class Tubulinea. When a discosean is in motion, a transparent layer called hyaloplasm forms at the leading edge of the cell. In some discoseans, short "subpseudopodia" may be extended from this hyaloplasm, but the granular contents of the cell do not flow into these, as in true pseudopodia. Discosean amoebae lack hard shells, but some, like Cochliopodium and Korotnevella secrete intricate organic scales which may cover the upper (dorsal) surface of the cell. No species have flagella or flagellated stages of life.
Arcellinid testate amoebae or Arcellinida, Arcellacean or lobose testate amoebae are single-celled protists partially enclosed in a simple test (shell).
Arcella is a genus of testate amoebae in the order Arcellinida, usually found in freshwaters and mosses, and rarely in soils. A key characteristic of Arcella is the circular test with a hole on its center from where finger-like pseudopods emerge. It is one of the largest testacean genera.
Apodera is a genus of amoeboid protists belonging to the family Hyalospheniidae, a group of shelled amoebae. Their shells, or tests, are lageniform with a clear constriction that separates the neck from the body.
Cryptodifflugia is a genus of arcellinid testate amoebae. It contains all the species previously grouped as the genus Difflugiella, which is now a synonym of Cryptodifflugia.
An amoeba, often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopods. Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals.
Hyalospheniidae is a family of arcellinid testate amoebae and the sole family of the infraorder Hyalospheniformes. Commonly referred to as "hyalospheniids", these lobose amoebae are characterized by their ability to generate a shell composed of either organic matter or siliceous particles that may be recycled from euglyphid amoebae. They inhabit soil or freshwater habitats, and are abundant on Sphagnum mosses.
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.
Certesella is a genus of testate amoebae belonging to the family Hyalospheniidae. It is characterized by a test that presents two symmetrical holes near the opening, and by the presence of internal teeth within the test. It contains four species previously assigned to Nebela, as well as one species discovered in 2021.
Cryptodifflugiidae is a family of arcellinid testate amoebae.
Meisterfeldia is a genus of arcellinid testate amoebae erected in 2016 that unites several new species as well as old species previously found in the genus Cryptodifflugia. Five of the newly described species were first found and isolated from subarctic tundra soil surrounding a river near Chokurdakh, Russia, while the last one, described in 2021, was recovered from tree hollows in Moscow.
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.
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.
Corycidia is a clade of amoeboid protists within the eukaryotic supergroup Amoebozoa. It contains all amoebae of the families Microcoryciidae, which was previously regarded as Arcellinida, and Trichosphaeriidae, which contains the sole genus Trichosphaerium.
Cryptodifflugia operculata is an amoebozoan in the Tubulinea class. They are testate amoebae due to the presence of a test that encapsulates its pseudopods. C. operculata's taxonomy has been categorized throughout the years, as well as its morphology. They are found mainly in freshwater, however they also can be found in soil. C. operculata is a predator that can consume prey larger than themselves, and is capable of forming packs and hunting.
