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Trepaxonemata
Trepaxonemata (from ''trepa''-, spiral + axoneme) is a subclass of the Platyhelminthes or flatworms.Ehlers, U. (1985). Das Phylogenetische System der Plathelminthes. Stuttgart: G. Fischer. It includes all parasitic flatworms (clade Neodermata) and several free-living species that were previously grouped in the now obsolete class Turbellaria. Therefore, it contains the majority of species in the phylum Platyhelminthes, excluding the Catenulida, and the Macrostomorpha. Description The Trepaxonemata are characterised by: * biflagellate spermatozoa * axoneme of the spermatozoa with a special type of dense core (9+“1” pattern). The axoneme in the spermatozoa of species of Trepaxonemata, also called "trepaxoneme" or "trepaxonematan axoneme" has nine peripheral doublets of microtubules as the usual 9+2 axoneme but the two central microtubules are replaced by a central core. This central core appears as a spiral when seen in longitudinal sections in transmission electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adiaphanida
Trepaxonemata (from ''trepa''-, spiral + axoneme) is a subclass of the Platyhelminthes or flatworms.Ehlers, U. (1985). Das Phylogenetische System der Plathelminthes. Stuttgart: G. Fischer. It includes all parasitic flatworms (clade Neodermata) and several free-living species that were previously grouped in the now obsolete class Turbellaria. Therefore, it contains the majority of species in the phylum Platyhelminthes, excluding the Catenulida, and the Macrostomorpha. Description The Trepaxonemata are characterised by: * biflagellate spermatozoa * axoneme of the spermatozoa with a special type of dense core (9+“1” pattern). The axoneme in the spermatozoa of species of Trepaxonemata, also called "trepaxoneme" or "trepaxonematan axoneme" has nine peripheral doublets of microtubules as the usual 9+2 axoneme but the two central microtubules are replaced by a central core. This central core appears as a spiral when seen in longitudinal sections in transmission electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acentrosomata
Trepaxonemata (from ''trepa''-, spiral + axoneme) is a subclass of the Platyhelminthes or flatworms.Ehlers, U. (1985). Das Phylogenetische System der Plathelminthes. Stuttgart: G. Fischer. It includes all parasitic flatworms (clade Neodermata) and several free-living species that were previously grouped in the now obsolete class Turbellaria. Therefore, it contains the majority of species in the phylum Platyhelminthes, excluding the Catenulida, and the Macrostomorpha. Description The Trepaxonemata are characterised by: * biflagellate spermatozoa * axoneme of the spermatozoa with a special type of dense core (9+“1” pattern). The axoneme in the spermatozoa of species of Trepaxonemata, also called "trepaxoneme" or "trepaxonematan axoneme" has nine peripheral doublets of microtubules as the usual 9+2 axoneme but the two central microtubules are replaced by a central core. This central core appears as a spiral when seen in longitudinal sections in transmission electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euneoophora
Trepaxonemata (from ''trepa''-, spiral + axoneme) is a subclass of the Platyhelminthes or flatworms.Ehlers, U. (1985). Das Phylogenetische System der Plathelminthes. Stuttgart: G. Fischer. It includes all parasitic flatworms (clade Neodermata) and several free-living species that were previously grouped in the now obsolete class Turbellaria. Therefore, it contains the majority of species in the phylum Platyhelminthes, excluding the Catenulida, and the Macrostomorpha. Description The Trepaxonemata are characterised by: * biflagellate spermatozoa * axoneme of the spermatozoa with a special type of dense core (9+“1” pattern). The axoneme in the spermatozoa of species of Trepaxonemata, also called "trepaxoneme" or "trepaxonematan axoneme" has nine peripheral doublets of microtubules as the usual 9+2 axoneme but the two central microtubules are replaced by a central core. This central core appears as a spiral when seen in longitudinal sections in transmission electron mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplimatricata
Trepaxonemata (from ''trepa''-, spiral + axoneme) is a subclass of the Platyhelminthes or flatworms.Ehlers, U. (1985). Das Phylogenetische System der Plathelminthes. Stuttgart: G. Fischer. It includes all parasitic flatworms (clade Neodermata) and several free-living species that were previously grouped in the now obsolete class Turbellaria. Therefore, it contains the majority of species in the phylum Platyhelminthes, excluding the Catenulida, and the Macrostomorpha. Description The Trepaxonemata are characterised by: * biflagellate spermatozoa * axoneme of the spermatozoa with a special type of dense core (9+“1” pattern). The axoneme in the spermatozoa of species of Trepaxonemata, also called "trepaxoneme" or "trepaxonematan axoneme" has nine peripheral doublets of microtubules as the usual 9+2 axoneme but the two central microtubules are replaced by a central core. This central core appears as a spiral when seen in longitudinal sections in transmission electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platyhelminthes
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek language, Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a Phylum (biology), phylum of relatively simple bilaterian, Segmentation (biology), unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates (having no coelom, body cavity), and have no specialized circulatory system, circulatory and respiratory system, respiratory organ (anatomy), organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food cannot be processed continuously. In traditional medicinal texts, Platyhelminthes are divided into Turbellaria, which are mostly non-parasitic animals such as planarians, and three entirely p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flatworms
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates (having no body cavity), and have no specialized circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food cannot be processed continuously. In traditional medicinal texts, Platyhelminthes are divided into Turbellaria, which are mostly non-parasitic animals such as planarians, and three entirely parasitic groups: Cestoda, Trematoda and Monogenea; however, since the turbellarians have since been proven not to be mono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission Electron Microscopy
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a sensor such as a scintillator attached to a charge-coupled device. Transmission electron microscopes are capable of imaging at a significantly higher resolution than light microscopes, owing to the smaller de Broglie wavelength of electrons. This enables the instrument to capture fine detail—even as small as a single column of atoms, which is thousands of times smaller than a resolvable object seen in a light microscope. Transmission electron microscopy is a major analytical method i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bothrioneodermata
Bothrioneodermata is a clade of flatworms containing the Bothrioplanida and the Neodermata Neodermata is a clade of rhabditophoran flatworms containing the parasitic groups Trematoda, Monogenea and Cestoda. Description All neodermatans are parasites, in many groups having a free-swimming larval stage. The most striking feature uniti .... References {{zoology-stub Platyhelminthes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricladida
A planarian is one of the many flatworms of the traditional class Turbellaria. It usually describes free-living flatworms of the order Tricladida (triclads), although this common name is also used for a wide number of free-living platyhelminthes. Planaria are common to many parts of the world, living in both saltwater and freshwater ponds and rivers. Some species are terrestrial and are found under logs, in or on the soil, and on plants in humid areas. The triclads are characterized by triply branched intestine and anteriorly situated ovaries, next to the brain. Today the order Tricladida is split into three suborders, according to their phylogenetic relationships: Maricola, Cavernicola and Continenticola. Formerly, the Tricladida was split according to habitats: Maricola, which is marine; Paludicola which inhabits freshwater; and Terricola, which is land-dwelling. Planaria exhibit an extraordinary ability to regenerate lost body parts. For example, a planarian split lengt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fecampiida
Fecampiida is an order of flatworms in the class Rhabditophora. It is a considerably recent clade, erected after molecular studies. Description The order Fecampiida, as currently defined, was erected based on molecular studies. They all are parasitic organisms and are united by a similar development of the basal bodies during spermiogenesis. Classification Three families of Fecampiida were initially classified in different flatworm orders: Urastomatidae and Genostomatidae were considered prolecithophorans, while Fecampiidae was considered a rhabdocoel. When the genus '' Notentera'' was discovered, its relationship with Fecampiidae was clear based on morphology, and both groups were united under Fecampiida. Further ultrastructural studies suggested that Urastomatidae and Genostomatidae were closely related to Fecampiidae and Notenteridae, which was confirmed by molecular studies. Due to similarities in the protonephridial flame bulb, sperm and spermiogenesis, as well as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prolecithophora
The ''Prolecithophora'' are an order consisting of an estimated 300 species of small (typically 0.2 – 12 mm, one species up to 50 mm), active, aquatic flatworms. The order lacks a common English name. Most species are shaped like an elongated, stylized droplet, and are opaque white or yellow; they frequently have contrasting bands or spots in colors, such as purple, yellow, red, or brown. They have no to three (normally two) pairs of pigment-cup eyes, and well-developed tactile and chemoreceptor senses. With few exceptions, species are protandric hermaphrodites with internal fertilization. Egg capsules are, according to species, glued to various hard surfaces; the young hatch as miniature copies of their parents. Ecology All prolecithophorans are aquatic, with most living in the oceans. Some species, especially those living in freshwater, are predators and scavengers, but many marine species are associated with colonial animals such as bryozoans or live as symbiont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
