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Rhabditophora Genera
Rhabditophora (from ''rhabdito''-, rhabdite + Greek language, Greek -φορος [-''phoros''], bearer, i.e., "rhabdite bearers") is a subphylum (previously a class) of flatworms. It includes all parasite, 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 Catenulida, 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 rh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrostomum Lignano
''Macrostomum lignano'' is a Wiktionary:free-living, free-living, hermaphroditic flatworm. It is transparent and of small size (adults reaching about 1.7 mm), and is part of the intertidal sand Meiobenthos, meiofauna of the Adriatic Sea. Originally a model organism for research on developmental biology and the evolution of the bilaterian body plan, it has since expanded to other important fields of research such as sexual selection and sexual conflicts, ageing and the evolution of the bilaterian body plan, ecotoxicology, and, more recently, genomics. Name The genus name "''Macrostomum''", meaning "big-mouthed", derives from the Greek language, Greek μάκρος ''makros'', "large", and στόμα, ''stoma'', mouth. The species name, ''lignano'', comes from the location where this species has so far been found, the sandy beaches and lagoons at and near Lignano Sabbiadoro, Italy. Biology ''Macrostomum lignano'', like all other flatworms, is an Segmentation (biology), unse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel Phenotypic trait, character or character state that has evolution, evolved from its ancestral form (or Plesiomorphy and symplesiomorphy, plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxon, taxa and is therefore Hypothesis#Scientific hypothesis, hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies Homology (biology), homology. Examples of apomorphy are the presence of Terrestrial locomotion#Posture, erect gait, fur, Evolution of mammalian auditory ossicles, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a Terrestrial locomotion#Posture, sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bradynectes
Macrostomorpha is a clade of free living flatworms in the group Rhabditophora. Description Species of Macrostomorpha are characterized by having the necks of the viscid gland and releasing gland emerging in a common collar of anchor cell microvilli. They also gave aciliary speratozoa and a pharynx of the simplex coronatus type. Macrostomorpha constitute a basal group in Rhabditophora, showing such plesiomorphic condition as entolecithal eggs and spiral cleavage Cleavage may refer to: Science * Cleavage (crystal), the way in which a crystal or mineral tends to split * Cleavage (embryo), the division of cells in an early embryo * Cleavage (geology), foliation of rock perpendicular to stress, a result of .... Another trait found among members of the clade is the presence of hard stylet in the male copulatory organ. Phylogeny and systematics Originally the clade Macrostomorpha was divided into two groups: Haplopharyngida (containing a single family, Haplopharyngidae) and Mac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricladida
Planarians (triclads) are free-living flatworms of the class Turbellaria, order Tricladida, which includes hundreds of species, found in freshwater, marine, and terrestrial habitats.pp 3., "Planarians (the popular name for the group as a whole), or triclad flatworms (the more scientific designation of the same group), are acoelomate bilaterians". Planarians are characterized by a three-branched intestine, including a single anterior and two posterior branches. Their body is populated by adult stem cells called neoblasts, which planarians use for regenerating missing body parts. Many species are able to regenerate any missing organ, which has made planarians a popular model in research of regeneration and stem cell biology. The genome sequences of several species are available, as are tools for molecular biology analysis. The order Tricladida is split into three suborders, according to their phylogenetic relationships: Maricola, Cavernicola and Continenticola. Formerly, the ... [...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 group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proseriata
Proseriata is an order of free-living flatworms in the class Rhabditophora with over 400 species described worldwide. Description Proseriate flatworms are minute aquatic organisms, usually with an elongate body. There are no strong synapomorphies for the group, but it is supported by molecular studies. The suggested synapomorphies include the lack of lamellated rhabdites, an otherwise synapomorphy of Rhabditophora, and some features of the ultrastructure of the protonephridia and the cilia of epidermal cells. Ecology Most proseriates occur in marine environments, at the coastal zones, and are particularly common in high-energy habitats with medium to coarse sediments, sometimes being the dominant animal group in such areas. They are also common in brackish water, but few species occur in freshwater. Most proseriates are carnivores or scavengers, but some species are ectoparasitic on marine crustacea Crustaceans (from Latin meaning: "those with shells" or "crusted ones") ... [...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 symbio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycladida
The Polycladida represents a highly diverse clade of free-living marine flatworms. They are known from the littoral to the sublittoral zone (extending to the deep hot vents), and many species are common from coral reefs. Only a few species are found in freshwater habitats. Description Polyclads range from to in length with a flattened, roughly oval, body shape and, in many cases, a pair of short tentacles on the head. They are distinguished from other related animals by the presence of a folded pharynx, an elongated intestine with numerous complex diverticula, and multiple ocelli. The etymology of the order name ''Polycladida'' corresponds to the two ancient Greek words (), meaning "numerous", and (), meaning "branch". It refers to the ramified shape of the intestine in these flatworms. Most polyclads hide away from direct light. However, some of the brightly colored species often are active during the day. With their flamboyant coloring they advertise their potential tox ... [...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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
