Other Definitions
cestoda (dict)
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Cestoda - For the musical collaboration named Tapeworm, see Tapeworm (band).
- Tapeworm is also an older name for computer virus.
Subclass Cestodaria
Amphilinidea
Gyrocotylidea
Subclass Eucestoda
Aporidea
Caryophyllidea
Cyclophyllidea
Diphyllidea
Lecanicephalidea
Litobothridea
Nippotaeniidea
Proteocephalidea
Pseudophyllidea
Spathebothriidea
Tetraphyllidea
Trypanorhyncha
In biology, Cestoda is the class parasitic flatworms, called tapeworms, that live in the digestive tracts of vertebrates as adults. In the adult stage, they have a round head called a "scolex," which may have hooks and suckers for attachment. Posterior to the scolex, they have one or more proglottids that hold the reproductive structures. The sum of the proglottids is called a strobilla. It is shaped thin like a strip of tape, which is the source of the common name tapeworm. As adults absorb food predigested by the host, they have no need for a digestive tract or a mouth. All cestodes have a nerve ring in the scolex with lateral trunks passing through the rest of the body. Like some other flatworms, cestodes use flame cells (protonephridia) for excretion. Symptoms vary widely, depending on the species causing the infection. The large tapeworms can be 20 m or longer. Mature proglottids are released from the mature tapeworm and leave the host in its feces. Different types of tapeworms have different larval stags, which will not be discussed here. There are two subclasses in class Cestoda, the Cestodaria and the Eucestoda. By far the most common and widespread are the Eucestoda, with only a few species of unusual worms in subclass Cestodaria. The cyclophyllideans are of the most importance to humans because they infect people and livestock. Reference - Campbell, Reece, and Mitchell, Biology, 1999
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