Proglottis

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A single, segment-like reproductive member of a tapeworm is referred to as a proglottis ( plural proglottids; gr. Pro 'vor' and glossa , genitive glottis 'tongue'; literally "tongue tip", since they resemble the tongue tip in some species) . Tapeworms (Cestoda) consist of a head ( Scolex ) and an often very large number of tapeworm limbs, the proglottids. In their entirety, they form the tapeworm chain ( strobila ). The proglottids are separated from one another by an externally visible transverse furrow, but have no dividing wall (pseudo-segment) inside. In some tapeworms ( Caryophyllidia , Spathebothriida ) this classification of the tapeworm chain is absent or is at best indicated.

In the proglottids, which contain a single or double hermaphroditic sexual apparatus, the tapeworms reproduce generatively. The female sexual apparatus consists of the ovary (Syn. Germarium), the yolk (Vitellarium), the ootype , the mating duct and the uterus . The latter fills more and more with eggs while the remaining sections recede. As soon as they are filled with eggs as "ripe" proglottids, they detach at the end of the tapeworm by constriction, while the youngest still "immature" limbs grow shortly behind the front end or head. The male sexual apparatus consists of the testicles , their excretory ducts and the spermatic duct , which opens into the cirrus sac . In addition, the proglottids contain nerve cords and protonephridial cells as excretory organs . In many types of tapeworm, there are also calcareous bodies .

literature

  • Josef Boch, Christian Bauer: Veterinary Parasitology . Georg Thieme, Stuttgart 2006, ISBN 978-3-8304-4135-9 , p. 66 .