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Ribeiroia
''Ribeiroia'' () is a genus of trematode parasites that sequentially infect freshwater snails in the family Planorbidae (ramshorn snails) as first intermediate hosts, fish and larval amphibians as second intermediate hosts, and birds and mammals as definitive hosts (see ). In North America, infection by ''Ribeiroia'' has been linked to amphibians with limb malformations. The connection between parasitic infection and limb malformations has generated questions about (a) whether parasite-induced malformations in amphibians are increasing (see ), and (b) the consequences of such abnormalities for amphibian population conservation (see ). Taxonomy ''Ribeiroia'' is a genus of parasites in the class Trematoda, phylum Platyhelminthes. Currently three species and one subspecies of ''Ribeiroia'' are recognized: '' R. ondatrae'' in North America, ''R. marini'' in the Caribbean, ''R. m. guadeloupensis'' on the Caribbean island of Guadeloupe, and ''R. congolensis'' in Africa (Johnson ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribeiroia Congolensis
''Ribeiroia'' () is a genus of trematode parasites that sequentially infect freshwater snails in the family Planorbidae (ramshorn snails) as first intermediate hosts, fish and larval amphibians as second intermediate hosts, and birds and mammals as definitive hosts (see ). In North America, infection by ''Ribeiroia'' has been linked to amphibians with limb malformations. The connection between parasitic infection and limb malformations has generated questions about (a) whether parasite-induced malformations in amphibians are increasing (see ), and (b) the consequences of such abnormalities for amphibian population conservation (see ). Taxonomy ''Ribeiroia'' is a genus of parasites in the class Trematoda, phylum Platyhelminthes. Currently three species and one subspecies of ''Ribeiroia'' are recognized: '' R. ondatrae'' in North America, ''R. marini'' in the Caribbean, ''R. m. guadeloupensis'' on the Caribbean island of Guadeloupe, and ''R. congolensis'' in Africa (Johnson ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribeiroia Ondatrae
''Ribeiroia ondatrae'', or the frog-mutating flatworm is a parasite in the genus ''Ribeiroia'' which is believed to be responsible for many of the recent increases in amphibian limb malformations, particularly missing, malformed, and additional hind legs. It was first reported from livers of '' Ondatra'', hence its specific name. In recent studies, it was found that in areas infected with ''R. ondatrae'', the population of amphibian limb malformations was much higher than populations in which this trematode was not present. Each species studied showed varying results. For example, amphibians of species '' Pseudacris regilla'', '' Rana aurora'' and '' Taricha torosa'' were found to physically display a higher frequency in the number of abnormalities. The exact mechanism of deformation has not been determined but it has been theorized that deformation results from mechanical disruption of the cells involved in limb bud formation during the amphibian larval stage. Life cycle Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miracidia
Trematodes are parasitic flatworms of the class ''Trematoda'', specifically parasitic flukes with two suckers: one ventral and the other oral. Trematodes are covered by a tegument, that protects the organism from the environment by providing secretory and absorptive functions. The life cycle of a typical trematode begins with an egg. Some trematode eggs hatch directly in the environment (water), while others are eaten and hatched within a host, typically a mollusc. The hatchling is called a '' miracidium,'' a free-swimming, ciliated larva. Miracidia will then grow and develop within the intermediate host into a sac-like structure known as a sporocyst or into rediae, either of which may give rise to free-swimming, motile cercariae larvae. The cercariae then could either infect a vertebrate host or a second intermediate host. Adult metacercariae or mesocercariae, depending on the individual trematode's life cycle, will then infect the vertebrate host or be rejected and excreted t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about long in adults, that travels behind the trachea and heart, passes through the diaphragm, and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word ''oesophagus'' is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω (phérō, “I carry”) + ἔφαγον (éphagon, “I ate”). The wall of the esophagus from the lumen outwards consists of mucosa, submucosa (connective tissue), layers of muscle fibers between layers of fibrous tissue, and an outer layer of connective tissue. The mucosa is a stratified squamous epith ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guadeloupe Guadeloupe (; ; gcf, label=Antillean Creole, Gwadloup, ) is an archipelago and overseas department and region of France in the Caribbean. It consists of six inhabited islands— Basse-Terre, Grande-Terre, Marie-Galante, La Désirade, and the two inhabited Îles des Saintes—as well as many uninhabited islands and outcroppings. It is south of Antigua and Barbuda and Montserrat, north of the Commonwealth of Dominica. The region's capital city is Basse-Terre, located on the southern west coast of Basse-Terre Island; however, the most populous city is Les Abymes and the main centre of business is neighbouring Pointe-à-Pitre, both located on Grande-Terre Island. It had a population of 384, |
