1. Platyhelminthes pt 2 Digene trematodes and tapeworms

2. Turbellaria Monogenea Trematoda Cestoda Cilia lost from ectoderm (parasitic lifestyle) Microtriches Scolex Proglottids Acetabulum endoparasite Mollusc/vertebrate life cycle Opisthaptor Ectoparasite One host Free living Phylum Platyhelminthes

3. Di(2)-Gene(birth) 2 or more hosts Endoparasitic No cilia on skin, skin is syncytial Life cycle: Adults in definitive host (a vertebrate) reproduce sexually → eggs in host’s feces released into water → hatch into ciliated larva (=miricidium) → snail (intermediate host) → asexual reproduction → sporocyte → redia → cercaria released from snail → metacercaria encysts in 2 nd intermediate host (or forage in some cases) → ingested by definitive host

4. Schistosoma mansoni

5. 200 million infected worldwide Leading cause of death of Egyptian men 20-44 years old Adults live in mesenteric veins, veins associated with bladder Damage caused by unegested eggs (50% never released) Control: clean water, sewage control, snail reduction Exacerbating factors: poverty & ignorance, dams

6. Swimmer’s itch Schistosoma sp. that infect ducks, muskrat

7. Blackspot disease: Uvulifer sp.

8. Fasciola hepatica (sheep liver fluke) F. gigantica (human liver fluke)

9. Dicrocoelium dendriticum = a bile duct fluke of ruminants such as sheep, goats, deer, pigs.

10. Tuesday November 13 th CMU Ballroom Make a team of 3 – 4 students & sign up on the poster outside SL 118 by October 16 th !! For more information: Tri-Beta Meeting October 2 nd 6:00 SL118 Chem Club Meeting October 3 rd 7:00 HA 405 Or contact Marissa Schafer at marissaschafer@hotmail.com

11. Turbellaria Monogenea Trematoda Cestoda Cilia lost from ectoderm (parasitic lifestyle) Microtriches Scolex Proglottids Acetabulum endoparasite Mollusc/vertebrate life cycle Opisthaptor Ectoparasite One host Free living Phylum Platyhelminthes

12. Class Cestoda - Tapeworms Obligate endoparasites of vertebrates Lack digestive tract Have scolex for attachment to host Body divided into proglottids –Each proglottid = egg factory with its own ovary and testis (make up to 50,000 eggs per proglottid) –Worm = hundreds to thousands of proglottids

13. General life cycle of tapeworms Adult in intestine of definitive host → proglottids break off and pass with feces → eggs released from proglottid → eaten by intermediate host → oncosphere larva → intermed host ingested by definitive host → adult develops in intestine

15. Tapeworms Scolex

16. Echinococcus granulosis – a tapeworm of dogs & dingoes

17. Dipylidium caninum

18. Beef tapeworm: Taenia saginata Attains a length of 10m

19. Ligula intestinalis Egg → copepod (encycts as a procercoid) → fish (encysts as a plerocercoid larva) → ingested by final host → adult tapeworm in gut of bird