Cercaria | |
---|---|
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Platyhelminthes |
Class: | Trematoda |
Order: | Plagiorchiida |
Family: | Fellodistomidae |
Genus: | Cercaria Müller, 1773 |
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 cercarial life stage and the adult forms are not known. [1]
Species: [2]
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Digenea is a class of trematodes in the Platyhelminthes phylum, consisting of parasitic flatworms 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.
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A cercaria is the larval form of the trematode class of parasites. It develops within the germinal cells of the 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.
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Bucephalidae is a family of trematodes that parasitize fish. They lack suckers, having instead a muscular organ called a "rhynchus" at the front end which they use to attach to their hosts. The characteristics of the rhynchus are used to help define the genera of the family. It is one of the largest digenean families, with 25 genera containing hundreds of described species. Bucephalids are cosmopolitan, having been recorded all over the world. They are parasites of fish from freshwater, marine, and brackish water habitat types.
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