Introduction to Cestoda

I.                    Similar body plan:  Scolex, followed by a strobila of proglottids (segments).

a.      The newest, youngest segments are immature, with undeveloped male and female reproductive systems;

b.      Intermediate in distance are the mature proglottids, with functional male and female reproductive systems;

c.       The ones furthest away are gravid, in which the entire male reproductive system, and most of the female reproductive system have been completely resorbed.  A uterus, swollen with eggs, is left.

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II.                  Two major groups of cestodes reach sexual maturity in mammals:  Pseudophyllida, represented solely by Diphyllobothrium latum, the broad fish tapeworm, and Cyclophyllidea, represented by:

a.      Taeniarhynchus saginata (beef tapeworm)

b.      Taenia solium (pork tapeworm)

c.       Hymenolepis diminuta (rat tapeworm)

d.      Vampirolepis nana (small rat tapeworm)

e.      Dipylidium caninum (dog tapeworm)

f.        Echinococcus granulosus (small dog tapeworm)

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III.                Larval forms

See:  http://www.path.cam.ac.uk/~schisto/general_parasitology/parasitology_cestodes_larvae.html