Trematoda

Class of parasitic flatworms

Trematoda is a class within the phylum Platyhelminthes, commonly known as flukes. These are parasitic flatworms, with a complex life cycle involving multiple hosts. Trematodes are significant as they include species that are important parasites of humans and other animals.

Morphology

Trematodes are typically flattened and leaf-shaped. They possess a tegument, which is a specialized outer covering that protects them from the host's digestive enzymes. Most trematodes have two suckers: an oral sucker, which surrounds the mouth, and a ventral sucker, which is used for attachment to the host.

Life Cycle

The life cycle of trematodes is complex and usually involves multiple hosts. The primary host is typically a vertebrate, where the adult flukes reside. Intermediate hosts are often mollusks, such as snails, where larval stages develop. The life cycle includes several stages: egg, miracidium, sporocyst, redia, cercaria, and metacercaria.

Reproduction

Trematodes are hermaphroditic, possessing both male and female reproductive organs. They can reproduce sexually within the primary host. Some species also exhibit asexual reproduction during their larval stages in the intermediate host.

Ecology

Trematodes are found in a variety of environments, from freshwater to marine ecosystems. They play a role in the ecosystem as parasites, affecting the population dynamics of their hosts.

Human Health

Several species of trematodes are of medical importance, causing diseases such as schistosomiasis, liver fluke infections, and lung fluke infections. These diseases are prevalent in tropical and subtropical regions and are associated with significant morbidity.

Related pages

• Platyhelminthes
• Parasitism
• Schistosomiasis

References

• Roberts, L. S., & Janovy, J. (2009). Foundations of Parasitology. McGraw-Hill.
• Smyth, J. D., & Halton, D. W. (1983). The Physiology of Trematodes. Cambridge University Press.

Trematoda

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Trematoda

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  Botulus microporus

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  Trematodes illustration from Encyclopædia Britannica 1911