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Bigyra
Bigyra () is a phylum of microscopic eukaryotes that are found at the base of the Stramenopiles clade. It includes three well-known heterotrophic groups Bicosoecida, Opalinata and Labyrinthulomycetes, as well as several small clades initially discovered through environmental DNA samples: Nanomonadea, Placididea, Opalomonadea and Eogyrea. The classification of Bigyra has changed several times since its origin, and its monophyly remains unresolved. Ecological diversity Bigyra is a diverse group of heterotrophic, mainly phagotrophic stramenopiles that lack cell walls. It contains three well-known important groups with widely different ecological functions and morphologies: labyrinthulomycetes, opalines and bicosoecids. Labyrinthulomycetes is a group of protists that absorb nutrients in an osmotrophic or phagotrophic manner. They can behave either as free-living amoebae or as mycelium-like networks of cytoplasmic threads. Some of them are saprotrophic decomposers of the detritus, de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protists
A protist ( ) or protoctist is any Eukaryote, eukaryotic organism that is not an animal, Embryophyte, land plant, or fungus. Protists do not form a Clade, natural group, or clade, but are a Paraphyly, paraphyletic grouping of all descendants of the last eukaryotic common ancestor excluding land plants, animals, and fungi. Protists were historically regarded as a separate taxonomic rank, taxonomic kingdom (biology), kingdom known as Protista or Protoctista. With the advent of phylogenetic analysis and electron microscopy studies, the use of Protista as a formal taxon was gradually abandoned. In modern classifications, protists are spread across several eukaryotic clades called supergroup (biology), supergroups, such as Archaeplastida (photoautotrophs that includes land plants), SAR supergroup, SAR, Obazoa (which includes fungi and animals), Amoebozoa and "Excavata". Protists represent an extremely large genetic diversity, genetic and ecological diversity in all environments, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Labyrinthulomycetes
Labyrinthulomycetes (ICNafp) or Labyrinthulea (ICZN) is a class of protists that produce a network of filaments or tubes, which serve as tracks for the cells to glide along and absorb nutrients for them. The two main groups are the labyrinthulids (or slime nets) and thraustochytrids. They are mostly marine, commonly found as parasites on algae and seagrasses or as decomposers on dead plant material. They also include some parasites of marine invertebrates and mixotrophic species that live in a symbiotic relationship with zoochlorella. Characteristics Although they are outside the cells, the filaments of Labyrinthulomycetes are surrounded by a membrane. They are formed and connected with the cytoplasm by a unique organelle called a sagenogen or bothrosome. The cells are uninucleated and typically ovoid, and move back and forth along the amorphous network at speeds varying from 5-150 μm per minute. Among the labyrinthulids, the cells are enclosed within the tubes, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stramenopiles
The stramenopiles, also called heterokonts, are Protist, protists distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface, and in some they have been secondarily lost (in which case relatedness to stramenopile ancestors is evident from other shared cytological features or from genetic similarity). Stramenopiles represent one of the three major clades in the SAR supergroup, SAR Supergroup (biology), supergroup, along with Alveolate, Alveolata and Rhizaria. Stramenopiles are Eukaryote, eukaryotes; most are single-celled, but some are multicellular including some large seaweeds, the brown algae. The group includes a variety of algal protists, heterotrophic flagellates, opalines and closely related proteromonad flagellates (all Endosymbiont, endobionts in other organisms); the actinophryid Heliozoa, and oomycetes. The tripartite hairs characteristic of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Labyrinthulomycetes
Labyrinthulomycetes (ICNafp) or Labyrinthulea (ICZN) is a class of protists that produce a network of filaments or tubes, which serve as tracks for the cells to glide along and absorb nutrients for them. The two main groups are the labyrinthulids (or slime nets) and thraustochytrids. They are mostly marine, commonly found as parasites on algae and seagrasses or as decomposers on dead plant material. They also include some parasites of marine invertebrates and mixotrophic species that live in a symbiotic relationship with zoochlorella. Characteristics Although they are outside the cells, the filaments of Labyrinthulomycetes are surrounded by a membrane. They are formed and connected with the cytoplasm by a unique organelle called a sagenogen or bothrosome. The cells are uninucleated and typically ovoid, and move back and forth along the amorphous network at speeds varying from 5-150 μm per minute. Among the labyrinthulids, the cells are enclosed within the tubes, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opalozoa
Opalozoa is a subphylum of heterotrophic protists of the phylum Bigyra, and is the sister group to Sagenista. Opalozoans are non-photosynthetic heterokonts that are ancestrally phagotrophic but many times have evolved to be osmotrophic saprotrophs in the gut of vertebrate animals. Taxonomy History: phylum Opalozoa In 1993 the name “Opalozoa” referred to a group of protists that was very different from what it is now. It was a phylum composed of many unrelated zooflagellates, grouped together because of the common presence of tubular mitochondrial cristae and the lack of cortical alveoli or rigid tubular ciliary hairs ( retronemes). It also included the opalinids, proteomyxids and plasmodiophorids. Modern classification The modern taxonomy of Opalozoa, down to order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylum
In biology, a phylum (; : phyla) is a level of classification, or taxonomic rank, that is below Kingdom (biology), kingdom and above Class (biology), class. Traditionally, in botany the term division (taxonomy), division has been used instead of phylum, although the International Code of Nomenclature for algae, fungi, and plants accepts the terms as equivalent. Depending on definitions, the animal kingdom Animalia contains about 31 phyla, the plant kingdom Plantae contains about 14 phyla, and the fungus kingdom Fungi contains about eight phyla. Current research in phylogenetics is uncovering the relationships among phyla within larger clades like Ecdysozoa and Embryophyta. General description The term phylum was coined in 1866 by Ernst Haeckel from the Greek (, "race, stock"), related to (, "tribe, clan"). Haeckel noted that species constantly evolved into new species that seemed to retain few consistent features among themselves and therefore few features that distinguishe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eogyrea
Sagenista is a group of heterokonts containing the labyrinthulids and Eogyrea, a class of yet uncultured protists. Originally, it contained the Labyrinthulids and bicosoecids. The bicosoecids have been removed, and Eogyrea were added, in order to make the group monophyletic. Some have a special organelle called a bothrosome (or sagenogenetosome). It is usually found in a marine environments rich in algae and sea grass. It is capable of movement by use of this organelle. They are generally decomposers. They are cultivated for their active production of Omega-3 fatty acids. These acids are used as an approved additive for animal feed. There is a debate about whether some species of Sagenista contain the photosynthetic pigment chlorophyll C. Bothrosome They are capable of excreting an extoplasmic net of filaments for cells to glide upon. These tiny filaments provide a network for cells to travel upon to soak up nutrients from the surrounding environment. Examples *''Labyrinthu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opalinata
Opalinata is a superclass of non- phagotrophic heterokonts that unites the classes Opalinea and Blastocystea, and is the sister group to Opalomonadea. Description When Opalinata was first erected as a taxon in 1926, it was placed as the sole class in the group "Protociliata" and considered as primitive ciliates due to the fact that they move thanks to their numerous cilia and that they both present two nuclei. They were distinguished because they perform syngamy by the complete fusion of uninucleated gametes, while the rest of ciliates, forming "Euciliata" ( Ciliata + Suctoria), perform syngamy through their micronuclei alone while their macronuclei dissolve. The taxon Opalinata was revised in 1996 by Cavalier-Smith and placed in Opalozoa, and is now defined by the following synapomorphies: gut parasitism and the loss of peroxisomes and phagocytosis Phagocytosis () is the process by which a cell (biology), cell uses its plasma membrane to engulf a large particle (≥ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagenista
Sagenista is a group of heterokonts containing the labyrinthulids and Eogyrea, a class of yet uncultured protists. Originally, it contained the Labyrinthulids and bicosoecids. The bicosoecids have been removed, and Eogyrea were added, in order to make the group monophyletic. Some have a special organelle In cell biology, an organelle is a specialized subunit, usually within a cell (biology), cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as Organ (anatomy), organs are to th ... called a bothrosome (or sagenogenetosome). It is usually found in a marine environments rich in algae and sea grass. It is capable of movement by use of this organelle. They are generally decomposers. They are cultivated for their active production of Omega-3 fatty acids. These acids are used as an approved additive for animal feed. There is a debate about whether some species of Sagenista contain the photosynthetic pigme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phagotroph
Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is called a phagocyte. In a multicellular organism's immune system, phagocytosis is a major mechanism used to remove pathogens and cell debris. The ingested material is then digested in the phagosome. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytized. Some protozoa use phagocytosis as means to obtain nutrients. The two main cells that do this are the Macrophages and the Neutrophils of the immune system. Where phagocytosis is used as a means of feeding and provides the organism part or all of its nourishment, it is called phagotrophy and is distinguished from osmotrophy, which is nutrition taking place by absorption. History The history of phagocytosis represents the scienti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplanochytrium
The genus ''Aplanochytrium'' is part of the class Labyrinthulomycetes. It is a sister genus of '' Labyrinthula'' and thraustochytrids. The major characteristic of all three genera is the production of an extension of the plasma membrane and the ectoplasm called the ectoplasmic net, but its use is different in each genera. ''Aplanochytrium'' cells are not embedded in the ectoplasmic net but can move by gliding on the ectoplasmic threads. Cells of the genus ''Aplanochytrium'' multiply by forming aplanospores in a spherical sporangium. The spores are then released and they move away by crawling along their own ectoplasmic thread. The aplanospores are non-flagellated asexual spores. ''Aplanochytrium'' is found exclusively in marine environments and lives on diverse host organisms. The symbiosis between ''Aplanochytrium'' cells and the host organism can be of various origins, like commensal or parasite. Etymology The genus ''Aplanochytrium'' was identified as a member of the Labyri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
