Cestoda

In Biology, the cestodes ( Cestoda ) are a class of Plathelminthes parasite S whose adults live in the digestive Tract Vertébré S. They have a round higher end, the Scolex with hooks and suction cups which enable them to cling. Behind the scolex, they have a neck in growth then a Strobile finished by the Proglotides (immature, mature, pregnant) which contain many eggs. As they strictly speaking do not have a digestive tract, they absorb the food prédigérée by the host: they are osmotrophes .

The Bothriocéphales and the Ténia S are cestodes.

The cestodes have a flat, segmented body and a ribboned aspect. The cestodes are specialized in parasitism with bodies of fixing on the host and absence of digestive tract. They are Mésoparasite S. the segments have a fonction= to produce eggs (to 5000 eggs per day). the male segment is former and the segment female is posterior, thus the reproduction is done by autofecondation, folding up. In their cycle there practically does not exist free phase. There exist two important orders: the Cyclophyllidien S, whose scolex has 4 suction cups, and the Bothricéphales, whose scolex carries longitudinal pseudobothridies which act as suction cups. Many animals can be parasitized by a bothricéphale such as the seals, foxes, bear, pigs, dogs, cats and of course the Man. The larvae of bothricéphale evolve/move in a shellfish: the cyclops. This last will be consumed by other fish and the man will contaminate himself by eating believed or insufficiently cooked fish.

The bothricéphales cause same the disorders overall that the tapeworms with noting a deficiency in B12 vitamin causing an anemia mégalocytaire.

Reference

Campbell, Reece, and Mitchell, Biology , 1999

Simple: Tapeworm

Random links: