FUNCTIONAL MORPHOLOGY OF CESTODE LARVAE.

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Publisher Summary This chapter discusses functional morphology of cestode larvae that shows great variability during postembryonic development. The chapter begins with description of the oncospheral stage and its development that is formation of embryonic envelopes and the development of the penetration glands, hooklets, and their muscles. Then, there is consideration of the structure of the oncosphere (hexacanth), its functional capability at the infective stage and subsequent metamorphosis. Post-oncocercal development of larvae that form and do not form the cavity is also discussed. Special treatment is given to the functional morphology of the strobilar tegument of adult stages, histogenesis of the calcareous corpuscles, and morphogenesis of the mature plerocercoid to the adult stage. The scolex of larval Taeniidae is examined in the cysticercoid and cysticercus, also the cyst wall of the cysticercoid and the cysticercus bladder. Excystment of the cysticercoid and evagination of the cysticercus are noted. A sexual multiplication and abnormal growth are other topics dealt with. In conclusion the chapter discusses that successful cultivation of the oncosphere and other larval stages has produced much of this new information about the physiology of larval cestodes with the help of histochemistry and electron microscopy, information that facilitates more precise placing of these cestode parasites in the whole zoological system and improves the understanding of host-parasite relationships.Â