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Cercaria
A cercaria (plural cercariae) is a larval form of the trematode class of parasites. It develops within the germinal cells of the Trematode life cycle stages, sporocyst or redia. A cercaria has a tapering head with large penetration glands. It may or may not have a long swimming "tail", depending on the species. The motile cercaria finds and settles in a host where it will become either an adult, or a mesocercaria, or a metacercaria, according to species. Cercarial infection in water environments by non-human Schistosomatidae, schistosome species causes dermatologic burden to nearby swimmers, fishermen and farmers. The cycle as mentioned above, starts with egg distribution whether fecal in route or from the nostril of a duck or goose. Miracidia infect snail reservoirs and form successive sporocysts. Released cercariae travel and infect nearby non-human mammals or birds, depending on species, or accidental hosts such as humans. This dead-end infection and host allergic reaction ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cercaria (genus)
''Cercaria'' is the name of a genus of trematodes in the subclass Digenea. It is used as a placeholder genus when the species description is based on the Cercaria, cercarial life stage and the adult forms are not known. List Species: *''Cercaria armata'' *''Cercaria brevicaeca'' *''Cercaria brookoveri'' *''Cercaria burti'' *''Cercaria caryi'' *''Cercaria chrysenterica'' *''Cercaria cloacicola'' *''Cercaria columbiensis'' *''Cercaria dermolestes'' *''Cercaria diastropha'' *''Cercaria dipterocerca'' *''Cercaria douglasi'' *''Cercaria douthitti'' *Cercaria elegans (Hong Kong larval trematode), ''Cercaria elegans'' *''Cercaria elongata'' *''Cercaria elvae'' *''Cercaria emarginatae'' *''Cercaria gedoelsti'' *''Cercaria gyrauli'' *''Cercaria hamata'' *''Cercaria hemilophura'' *''Cercaria hezuiensis'' *''Cercaria himasthloides'' *''Cercaria hongkongensis'' *''Cercaria inhabilis'' *''Cercaria isocotylea'' *''Cercaria laevicardi'' *''Cercaria leptacantha'' * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schistosomiasis
Schistosomiasis, also known as snail fever, bilharzia, and Katayama fever is a neglected tropical helminthiasis, disease caused by parasitism, parasitic Schistosoma, flatworms called schistosomes. It affects both humans and animals. It affects the urinary tract or the intestines. Symptoms include abdominal pain, diarrhea, blood in stool, bloody stool, or hematuria, blood in the urine. Those who have been Infection, infected for a long time may experience liver damage, kidney failure, infertility, or bladder cancer. In children, schistosomiasis may cause failure to thrive, poor growth and learning disability, learning difficulties. Schistosomiasis is spread by contact with fresh water contaminated with parasites. These parasites are released from infected freshwater snails. The disease is especially common among children in Developing country, underdeveloped and developing countries because they are more likely to play in contaminated water. Schistosomiasis is also common among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematode Life Cycle Stages
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] |
Trematode
Trematoda is a Class (biology), class of flatworms known as trematodes, and commonly as flukes. They are obligate parasite, obligate Endoparasites, internal 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 a Mollusca, mollusk, usually a snail. The definitive host, where the flukes Sexual reproduction, sexually reproduce, is a vertebrate. Infection by trematodes can cause disease in all five 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. The etymology of trematode stems from the Ancient Greek, Greek word ''trēmatṓdēs'', which means "pierced with holes", and refers to the worm's sucker (zoology), sucker, which pierces a hole in the host while the worm is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase of their life cycle. A larva's appearance is generally very different from the adult form (''e.g.'' caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. In the case of smaller primitive arachnids, the larval stage differs by having three instead of four pairs of legs. Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schistosomatidae
Schistosomatidae is a family of digenetic trematodes with complex parasitic life cycles. Immature developmental stages of schistosomes are found in molluscs and adults occur in vertebrates. The best studied group, the blood flukes of the genus ''Schistosoma'', infect and cause disease in humans. Other genera which are infective to non-human vertebrates can cause mild rashes in humans. Schistosomatids are dioecious (individuals are of separate sexes) which is exceptional with regards to their phylum, Platyhelminthes, in which most species are hermaphroditic (individuals possess both male and female reproductive systems). History The eggs of these parasites were first described by Theodor Bilharz, a German pathologist working in Egypt in 1851 who found the eggs during the course of an autopsy. He wrote two letters to his former teacher Karl Theodor Ernst von Siebold in May and August 1851 describing his findings. von Siebold wrote a paper (published in 1852) summarizing Bil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miracidia
The miracidium is the second stage in the life cycle of trematodes. When trematode eggs are laid and come into contact with fresh water, they hatch and release miracidium. In this phase, miracidia are ciliated and free-swimming. This stage is completed upon coming in contact with, and entering into, a suitable intermediate host for the purposes of asexual reproduction. Many different species of ''Trematoda'' exist, expressing some variation in the physiology and appearance of the miracidia. The various trematode species implement similar strategies to increase their chances of locating and colonizing a new host. Anatomy ''Hirudinella ventricosa'' The trematode '' Hirudinella ventricosa'' releases eggs in strings. Each egg contains a single miracidium, while the string contains living spermatozoa. Miracidia have cilia that are only present in the upper portion of the body near an apical gland with 12 hook-like spines in the opening. ''Echinostoma paraensei'' Miracidia usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Spot Disease (fish)
Black spot disease is a disease affecting fish. It is caused by larvae ( metacercariae) of Diplostomatidae or Heterophyidae flatworms, which are encysted in the skin. It can affect both freshwater and marine fish. It appears as tiny black spots on the skin, fins, and flesh of the fish. The life cycle of the parasite typically involves a fish-eating bird, a snail and a fish. The black spot larvae grow to sexual maturity in the infected bird's intestine. The adult worms pass eggs with the bird's droppings. When the eggs reach water, they hatch into free-swimming organisms which then penetrate snails for further development. Finally, after leaving the snails they burrow into the skin of fish and form a cyst A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubb .... The fish surrounds the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fasciola Gigantica
''Fasciola gigantica'' is a parasitic flatworm of the Class (biology), class Trematoda, which causes tropical fascioliasis. It is regarded as one of the most important single platyhelminth infections of ruminants in Asia and Africa. The infection is commonly called fasciolosis. The prevalence of ''F. gigantica'' often overlaps with that of ''Fasciola hepatica'', and the two species are so closely related in terms of genetics, behaviour, and morphology (biology), morphological and anatomy, anatomical structures that distinguishing them is notoriously difficult. Therefore, sophisticated molecular techniques are required to correctly identify and diagnose the infection. Distribution ''Fasciola gigantica'' causes outbreaks in tropical areas of South Asia, Southeast Asia, and Africa. The geographical distribution of ''F. gigantica'' overlaps with ''F. hepatica'' in many African and Asian countries and sometimes in the same country, although in such cases, the ecological requirement o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fasciolopsis Buski
''Fasciolopsis'' () is a genus of trematodes. They are also known as giant intestinal flukes. Only one species is recognised: ''Fasciolopsis buski''. It is a notable parasite of medical importance in humans and veterinary importance in pigs. It is prevalent in Southern and Eastern Asia. The term for infestation with ''Fasciolopsis'' is fasciolopsiasis. ''Fasciolopsis buski'' ''Fasciolopsis buski'' is commonly called the giant intestinal trematoda, fluke, because it is an exceptionally large parasitic fluke, and the largest known to parasitise humans. Its size is variable and a mature specimen might be as little as 2 cm long, but the body may grow to a length of 7.5 cm and a width of 2.5 cm. It is a common parasite of humans and pigs and is most prevalent in South Asia, Southern and Southeast Asia, Southeastern Asia. It is a member of the Family (biology), family Fasciolidae in the Order (biology), order Plagiorchiida. The Echinostomida are members of the class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotaria
''Rotaria'' is a genus of asexual, microscopic animal known as a bdelloid rotifer. Analysis published in 2007 of morphology and DNA sequence data of species from the genus confirmed that despite their asexual mechanism of reproduction, two fundamental properties of species, independent evolution and ecological divergence by natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ... occurred. This demonstrates that sex is not a necessary condition for speciation. Fontaneto D, Herniou EA, Bosc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
