1. Platyhelminthes, Nematoda, Annelida

2. Phylum Platyhelminthes Flatworms - Dorsoventrally flattened (top to bottom) Digestive tract has one opening (incomplete) Simple nervous system No true circulatory or respiratory systems

3. Planaria

4. Planaria Regeneration

5. Lined Flatworm

9. Tapeworm parasitic

10. Tapeworm

11. Tapeworm in a Carp

12. Tapeworm

14. Tapeworms in dogs & cats Flea larvae

15. Flukes

16. Phylum Nematoda Long, tapered, cylindrical shape Longitudinal muscles

18. Phylum Nematoda Long, tapered, cylindrical shape Longitudinal muscles Complete Digestive system No circulatory or respiratory systems Roundworms

19. Parasitic Nematodes

20. Hookworms

21. Roundworm Life Cycle

22. Phylum Annelida Segmented worms Coelom (body cavity) Circular muscles Circulatory system (closed system)

24. Class Polychaeta “many bristles”

25. Bristle Worm

28. Christmas Tree Worm

30. Star Horseshoe Worm

31. Plume Worm

32. Social Feather Duster Worms

33. Medusa Worm

34. Class Oligochaeta “few bristles”

35. Earthworm Movement

37. Earthworms Mating

38. Class Hirudinea No bristles

39. Leech’s Mouth