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The Platyhelminthes have very few synapomorphies - distinguishing features that all Platyhelminthes (but no other animals) exhibit. This makes it difficult to work out their relationships with other groups of animals, as well as the relationships between different groups that are described as members of the Platyhelminthes.
Liver fluke is a collective name of a polyphyletic group of parasitic trematodes under the phylum Platyhelminthes. [1] They are principally parasites of the liver of various mammals, including humans. Capable of moving along the blood circulation, they can occur also in bile ducts, gallbladder, and liver parenchyma. In these organs, they ...
There may be as many as 300,000 species of parasites affecting vertebrates, [9] and as many as 300 affecting humans alone. [10] Helminths of importance in the sanitation field are the human parasites, and are classified as Nemathelminthes (nematodes) and Platyhelminthes, depending on whether they possess a round or flattened body, respectively. [8]
In 1955, Robert Thompson and James V. McConnell conditioned planarian flatworms by pairing a bright light with an electric shock. After repeating this several times they took away the electric shock, and only exposed them to the bright light. The flatworms would react to the bright light as if they had been shocked.
Tegument / ˈ t ɛ ɡ j ʊ m ə n t / is a term in helminthology for the outer body covering of members of the phylum Platyhelminthes. The name is derived from a Latin word tegumentum or tegere, meaning "to cover". [1] [2] It is characteristic of flatworms including the broad groups of tapeworms and flukes.
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.
The positive effects of parasitic worms are theorized to be a result of millions of years of evolution, when humans and human ancestors would have been constantly inhabited by parasitic worms. [9] In the journal EMBO Reports , Rook says that such helminths "are all either things that really do us no harm, or things where the immune system is ...
Trematoda is a class of flatworms known as flukes or trematodes.They are obligate internal parasites with a complex life cycle requiring at least two hosts.The intermediate host, in which asexual reproduction occurs, is usually a snail.