|
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] |
Fecampiidae
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] |
Genostomatidae
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] |
Notenteridae
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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urastomatidae
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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notentera
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 the ... [...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] |
Rhabditophora
Rhabditophora (from ''rhabdito''-, rhabdite + Greek -φορος ''phoros'' bearer, i.e., "rhabdite bearers") is a class of flatworms. It includes all parasitic flatworms (clade Neodermata) and most free-living species that were previously grouped in the now obsolete class Turbellaria. Therefore, it contains the majority of the species in the phylum Platyhelminthes, excluding only the catenulids, to which they appear to be the sister group. The clade Rhabditophora was originally erected by Ulrich Ehlers in 1985Ehlers, U. (1985) ''Phylogenetic relationships within the Platyhelminthes''. ''In'' S. Conway Morris; J. D. George; R. Gibson; H. M. Platt (Eds.), ''The origins and relationships of lower invertebrates''. Oxford, Clarendon Press, p. 143-158. based on morphological analyses and its monophyly was later confirmed by molecular studies. Description Rhabditophorans are characterized by the presence of lamellated rhabdites, rodlike granules secreted in the cells of the epidermis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhabdocoela
Rhabdocoela is an order of flatworms in the class Rhabditophora with about 1700 species described worldwide. The order was first described in 1831 by Christian Gottfried Ehrenberg. Most of rhabdocoels are free-living organisms, but some live symbiotically with other animals. Description Although Rhabdocoela is a highly supported group in molecular studies, there is no clear morphological synapomorphy that unites them. All rhabdocoels have a bulbous pharynx, but this is shared with other flatworm groups, such as Neodermata, Lecithoepitheliata and some species of Prolecithophora. Some possibly identified synapomorphies are found in the ultrastructure of the protonephridial system, but similar constructions exist in other groups. Another possible apomorphy is found in the ultrastructure of the sperm, which has a dense heel on the basal bodies during spermiogenesis, but some groups have lost this feature. Classification Rhabdocoels were traditionally classified in two groups, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Body
A basal body (synonymous with basal granule, kinetosome, and in older cytological literature with blepharoplast) is a protein structure found at the base of a eukaryotic undulipodium (cilium or flagellum). The basal body was named by Theodor Wilhelm Engelmann in 1880 It is formed from a centriole and several additional protein structures, and is, essentially, a modified centriole. The basal body serves as a nucleation site for the growth of the axoneme microtubules. Centrioles, from which basal bodies are derived, act as anchoring sites for proteins that in turn anchor microtubules, and are known as the microtubule organizing center (MTOC). These microtubules provide structure and facilitate movement of vesicles and organelles within many eukaryotic cells. Assembly, structure Cilia and basal bodies form during quiescence or the G1 phase of the cell cycle. Before the cell enters G1 phase, i.e. before the formation of the cilium, the mother centriole serves as a component of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermiogenesis
Spermiogenesis is the final stage of spermatogenesis, during which the spermatids develop into mature spermatozoa. At the beginning of the stage, the spermatid is a more or less circular cell containing a nucleus, Golgi apparatus, centriole and mitochondria; by the end of the process, it has radically transformed into an elongated spermatozoon, complete with a head, midpiece, and tail. Phases The process of spermiogenesis is traditionally divided into four stages: the Golgi phase, the cap phase, formation of the tail, and the maturation stage. Golgi phase The spermatids, which up until now have been mostly radially symmetrical, begin to develop polarity. The head forms at one end, where the Golgi apparatus creates enzymes that will become the acrosome. At the other end, it develops a thickened midpiece, where the mitochondria gather and the distal centriole begins to form an axoneme. Spermatid DNA also undergoes packaging, becoming highly condensed. The DNA is first packa ... [...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] |
