Platyhelminthes

Phylum :platyhelminthes.

Class : Cestoda

example here : tape worm.endoparasite in vertebrate's intestine

Characteristics : bilaterally symmetrical,has a distinct head with scolex to attach to intestinal wall.body usually very longflat and segmented.triploblastic :endo,ecto and mesoderm.

Reproduction :sexual :monoecious/hemaphrodite through proglottids (body segment).sperms fertilise eggs in the proglottids>separated from the worm>pass out in faeces>proglottids degenerate>eggs released(more than a ten thousands)

Pathway towards infecction:the released eggs eaten by animals>enzymes in animal stomach and intestine dissolve egg shell>oncosphere released>enter intestine>hepatic portal vein>liver>Right heart>lungs>left heart>general circulation>muscle where it encyst.>human eat animal meat>enzymes dissolve cyst>adult worms..

Uniqueness :it has more developed nervous system,it has sensory organs(eyespot to detect light)it has head..

so,it is important to cook fish to kill those worms!!