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Arcellidae
''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. Anatomy An ''Arcella'' is typically enclosed in a chitinous, umbrella-shaped test (or shell) that has a single central aperture through which the pseudopods – which are used for locomotion – extend out. In some species the aperture is surrounded by a ring of pores. The test is composed of organic material with a diameter of up to 300 µm and is transparent or light-yellow-colored in young ''Arcella'', but browns while aging due to the progressive deposition of iron and manganese compounds.Ralf Meisterfeld and Edward Mitchell (2008)"''Arcella'' Ehrenberg 1832" Contrary to other genera, no gravel chips or other foreign bodies are inserted to strengthen the housing. Different spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcella Dentata
''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. Anatomy An ''Arcella'' is typically enclosed in a chitinous, umbrella-shaped test (or shell) that has a single central aperture through which the pseudopods – which are used for locomotion – extend out. In some species the aperture is surrounded by a ring of pores. The test is composed of organic material with a diameter of up to 300 µm and is transparent or light-yellow-colored in young ''Arcella'', but browns while aging due to the progressive deposition of iron and manganese compounds.Ralf Meisterfeld and Edward Mitchell (2008)"''Arcella'' Ehrenberg 1832" Contrary to other genera, no gravel chips or other foreign bodies are inserted to strengthen the housing. Differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcella Megastoma
''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. Anatomy An ''Arcella'' is typically enclosed in a chitinous, umbrella-shaped test (or shell) that has a single central aperture through which the pseudopods – which are used for locomotion – extend out. In some species the aperture is surrounded by a ring of pores. The test is composed of organic material with a diameter of up to 300 µm and is transparent or light-yellow-colored in young ''Arcella'', but browns while aging due to the progressive deposition of iron and manganese compounds.Ralf Meisterfeld and Edward Mitchell (2008)"''Arcella'' Ehrenberg 1832" Contrary to other genera, no gravel chips or other foreign bodies are inserted to strengthen the housing. Different spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubulinea
The Tubulinea are a major grouping of Amoebozoa, including most of the more familiar amoebae genera like ''Amoeba'', '' Arcella'', '' Difflugia'' and '' Hartmannella''. Characteristics During locomotion most Tubulinea have a roughly cylindrical form or produce numerous cylindrical pseudopods. Each cylinder advances by a single central stream of cytoplasm, granular in appearance, and has no subpseudopodia. This distinguishes them from other amoeboid groups, although in some members this is not the normal type of locomotion. Classification This class was anticipated by some biologists like Jahn, who grouped all amoebae with granular pseudopodia together, but most split the lobose amoebae into testate Testacealobosia and naked Gymnamoebia. These latter are polyphyletic, but molecular trees by Bolivar ''et al.'' identified a core monophyletic subgroup. Subsequent studies showed the testate lobose amoebae belong to the same group, which was thus renamed Lobosea ''sensu stricto'' or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcellinida
Arcellinid testate amoebae or Arcellinida,http://www.microscopy-uk.org.uk/mag/artjun03/gsamoebae.html Testate amoebae, peat bogs and past climates. accessed 16 march 2007 Arcellacean or lobose testate amoebae are single-celled protists partially enclosed in a simple test (shell). Arcellinid testate amoebae are commonly found in soils, leaf litter, peat bogs and near/in fresh water. They use their pseudopodia, a temporary cell extension, for moving and taking in food. Like most amoebae, they are generally believed to reproduce asexually via binary fission. However a recent review suggests that sexual recombination may be the rule rather than the exception in amoeboid protists in general, including the Arcellinid testate amoebae. Test or shell Simple tests are made by secretion (autogenous tests), agglutination of foreign material (xenogenous tests), or sometimes a combination of both. Past environmental changes can be determined by analysing the composition of fossil tests, incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcellidae
''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. Anatomy An ''Arcella'' is typically enclosed in a chitinous, umbrella-shaped test (or shell) that has a single central aperture through which the pseudopods – which are used for locomotion – extend out. In some species the aperture is surrounded by a ring of pores. The test is composed of organic material with a diameter of up to 300 µm and is transparent or light-yellow-colored in young ''Arcella'', but browns while aging due to the progressive deposition of iron and manganese compounds.Ralf Meisterfeld and Edward Mitchell (2008)"''Arcella'' Ehrenberg 1832" Contrary to other genera, no gravel chips or other foreign bodies are inserted to strengthen the housing. Different spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
