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Digenea
Digenea (Gr. ''Dis'' – double, ''Genos'' – race) is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms (known as ''flukes'') with a syncytial tegument and, usually, two suckers, one ventral and one oral. Adults commonly live within the digestive tract, but occur throughout the organ systems of all classes of vertebrates. Once thought to be related to the Monogenea, it is now recognised that they are closest to the Aspidogastrea and that the Monogenea are more closely allied with the Cestoda. Around 6,000 species have been described to date. Morphology Key features Characteristic features of the Digenea include a syncytial tegument; that is, a tegument where the junctions between cells are broken down and a single continuous cytoplasm surrounds the entire animal. A similar tegument is found in other members of the Neodermata; a group of platyhelminths comprising the Digenea, Aspidogastrea, Monogenea and Cestoda. Digeneans possess a vermifo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opecoelidae
Opecoelidae is a family of trematodes. It is the largest digenean family with over 90 genera and nearly 900 species, almost solely found in marine and freshwater teleost fishes.Bray, Rodney A., Cribb, Thomas H., Littlewood, D. Timothy J. & Waeschenbach, Andrea (2016). The molecular phylogeny of the digenean family Opecoelidae Ozaki, 1925 and the value of morphological characters, with the erection of a new subfamily. ''Folia Parasitologica'', 63, 1–13. It was considered by Bray ''et al.'' to belong in the superfamily Opecoeloidea Ozaki, 1925 or the Brachycladioidea Odhner, 1905. Genera Family Opecoelidae *Subfamily Bathycreadiinae Martin, Huston, Cutmore & Cribb, 2018Martin, S. B., Huston, D. C., Cutmore, S. C. & Cribb, T. H. (2018). A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. ''Zoological Journal of the Linnean Society'', 186(2), 385–413. **Genus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicometra
''Helicometra'' is a genus of trematodes in the class Opecoelidae. It is synonymous with ''Allostenopera'' Baeva, 1968, ''Metahelicometra'' Yamaguti, 1971, and ''Stenopera'' Manter, 1933. Its type species is ''H. fasciata'' (Rudolphi, 1819). They are distinguished by their unique spiral uterus, from which their name is derived. Species *'' Helicometra aegyptensis'' Hassanine, 2007 *'' Helicometra antarcticae'' Holloway & Bier, 1968 *'' Helicometra aposinuata'' Pritchard, 1966 *'' Helicometra bassensis'' Woolcock, 1935 *'' Helicometra borneoensis'' Fischthal & Kuntz, 1965 *'' Helicometra boseli'' Nagaty, 1956 *'' Helicometra dalianensis'' (Li, Qiu & Zhang, 1989) *'' Helicometra dorabi'' (Mamaev & Oshmarin, 1966) *'' Helicometra equilata'' (Manter, 1933) *'' Helicometra fasciata'' (Rudolphi, 1819) *'' Helicometra filamentosa'' Madhavi, 1975 *'' Helicometra fusiformis'' Wang, Wang & Zhang, 1992 *'' Helicometra gibsoni'' Meenakshi, Madhavi & Swarnkumari, 1993 *''Helicometra gomphosi'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematoda
Trematoda is a Class (biology), class of flatworms known as flukes. They are obligate parasite, obligate internal Parasitism, parasites with a complex biological life cycle, life cycle requiring at least two Host_(biology), hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host, where the flukes sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five traditional vertebrate classes: mammals, birds, amphibians, reptiles, and fish. Etymology Trematodes are commonly referred to as flukes. This term can be traced back to the Old English name for flounder, and refers to the flattened, rhomboidal shape of the organisms. Taxonomy There are 18,000 to 24,000 known species of trematodes, divided into two subclasses — the Aspidogastrea and the Digenea. Aspidogastrea is the smaller subclass, comprising 61 species. These flukes mainly infect Bivalvia, bivalves and Osteichthyes, bony fishes.https://www.bi ... [...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] |
Flatworm
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 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 parasitic groups: Cestoda, Trematoda and Monogenea; however, since the turbellarians have since been prove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sucker (zoology)
A sucker in zoology refers to a specialised attachment organ of an animal. It acts as an adhesion device in parasitic worms, several flatworms, cephalopods, certain fishes, amphibians, and bats. It is a muscular structure for suction on a host or substrate. In parasitic annelids, flatworms and roundworms, suckers are the organs of attachment to the host tissues. In tapeworms and flukes, they are a parasitic adaptation for attachment on the internal tissues of the host, such as intestines and blood vessels. In roundworms and flatworms they serve as attachment between individuals particularly during mating. In annelids, a sucker can be both a functional mouth and a locomotory organ. The structure and number of suckers are often used as basic taxonomic diagnosis between different species, since they are unique in each species. In tapeworms there are two distinct classes of suckers, namely "bothridia" for true suckers, and " bothria" for false suckers. In digeneal flukes there ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetabulum (morphology)
Acetabulum (plural acetabula) in invertebrate zoology is a saucer-shaped organ of attachment in some annelid worms (like leech) and flatworms. It is a specialised sucker for parasitic adaptation in trematodes by which the worms are able to attach on the host. In annelids, it is basically a locomotory organ for attaching to a substratum. The name also applies to the suction appendage on the arms of cephalopod molluscs such as squid, octopus, cuttlefish, ''Nautilus'', etc. Etymology Acetabulum literally means "a small saucer for vinegar". It is derived from two Latin words ''acetum'', meaning "vinegar", and ''-bulum'', a suffix denoting "saucer" or "vessel" or "bowl". The name is used because of the saucer-like structure in the invertebrates. Structure Annelids In leeches, acetabulum refers to the prominent posterior sucker at the extreme end of the body. In fact it forms a head-like structure, while the actual head is relatively small. It is a thick disc-shaped muscular system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sucker (zoology)
A sucker in zoology refers to a specialised attachment organ of an animal. It acts as an adhesion device in parasitic worms, several flatworms, cephalopods, certain fishes, amphibians, and bats. It is a muscular structure for suction on a host or substrate. In parasitic annelids, flatworms and roundworms, suckers are the organs of attachment to the host tissues. In tapeworms and flukes, they are a parasitic adaptation for attachment on the internal tissues of the host, such as intestines and blood vessels. In roundworms and flatworms they serve as attachment between individuals particularly during mating. In annelids, a sucker can be both a functional mouth and a locomotory organ. The structure and number of suckers are often used as basic taxonomic diagnosis between different species, since they are unique in each species. In tapeworms there are two distinct classes of suckers, namely "bothridia" for true suckers, and " bothria" for false suckers. In digeneal flukes there ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspidogastrea
The Aspidogastrea (Ancient Greek: ' “shield”, ' “stomach/pouch”) is a small group of Trematoda, flukes comprising about 80 species. It is a Subclass (biology), subclass of the Trematode, trematoda, and sister group to the Digenea. Species range in length from approximately one millimeter to several centimeters. They are parasites of freshwater and ocean, marine molluscs and vertebrates (Chondrichthyes, cartilaginous and Actinopterygii, bony fishes and turtles). Maturation may occur in the mollusc or vertebrate host. None of the species has any economic importance, but the group is of very great interest to biologists because it has several characters which appear to be archaic. Morphology Shared characteristics Shared characteristics of the group are a large ventral disc with a large number of small Pulmonary alveolus, alveoli ("suckerlets") or a row of suckers and a Tegument (Helminth), tegument with short protrusions, so-called "microtubercles". Larval physiology Larv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plagiorchiida
Plagiorchiida is a large order of trematodes, synonymous to Echinostomida. They belong to the Digenea, a large subclass of flukes. This order contains relatively few significant parasites of humans. The following families are placed here, organised by superfamily and suborder:Jones, A., Bray, R. A., & Gibson, D. I. (Eds.). (2002). ''Keys to the Trematoda'' (Vol. 1). CABI Publishing and The Natural History Museum. * Apocreadiata ** Apocreadioidea Skrjabin, 1942 *** Apocreadiidae Skrjabin, 1942 * Bivesiculata ** Bivesiculoidea *** Bivesiculidae Yamaguti, 1934 * Bucephalata ** Bucephaloidea Poche, 1907 *** Bucephalidae Poche, 1907 *** Nuitrematidae Kurochkin, 1975 * Echinostomata ** Echinostomatoidea Looss, 1902 *** Caballerotrematidae Tkach, Kudlai & Kostadinova, 2016 *** Calycodidae Dollfus, 1929 *** Cyclocoelidae Stossich, 1902 *** Echinochasmidae Odhner, 1910 *** Echinostomatidae Looss, 1899 *** Fasciolidae Railliet, 1895 *** Himasthlidae Odhner, 1910 *** Philophthalm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the broomrapes. There are six major parasitic strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), trophicallytransmitted parasitism (by being eaten), vector-transmitted parasitism, parasitoidism, and micropredation. One major axis of classification concerns invasiveness: an endoparasite lives inside the host's body; an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelom
The coelom (or celom) is the main body cavity in most animals and is positioned inside the body to surround and contain the digestive tract and other organs. In some animals, it is lined with mesothelium. In other animals, such as molluscs, it remains undifferentiated. In the past, and for practical purposes, coelom characteristics have been used to classify bilaterian animal phyla into informal groups. Etymology The term ''coelom'' derives from the Ancient Greek word (), meaning 'cavity'. Structure Development The coelom is the mesodermally lined cavity between the gut and the outer body wall. During the development of the embryo, coelom formation begins in the gastrulation stage. The developing digestive tube of an embryo forms as a blind pouch called the archenteron. In Protostomes, the coelom forms by a process known as schizocoely. The archenteron initially forms, and the mesoderm splits into two layers: the first attaches to the body wall or ectoderm, forming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
