1. Phylum Annelida

2. Ancestral Traits –Coelomate –Lophotrochozoan –Protostome –Closed circulatory system –Cephalization Derived Traits –Segmentation Metamerism Septa –Setae Bristles –Myelinated neurons ~ 40K species of annelids Spirobranchus giganteus Christmas tree worm

3. Annelid Taxomony Class Polychaeta (many bristles) –most numerous # species –marine Hermodice crunculata

4. Annelid Taxomony Class Polychaeta Class Oligochaeta (few bristles) –Freshwater, marine & terrestrial Lumbricus terrestris

5. Annelid Taxomony Class Polychaeta Class Oligochaeta Class Hirudinea –Fixed # segments (34) –Setae absent Hirudo medicinalis

6. Annelid Phylogeny

7. Annelid Body Plan Setae

8. Class Polychaeta Highly specialized head regions –Antennae –Sensory palps –Feeding appendages Paired extensions of body (parapodia) Often tube-dwelling –Burrow into substrate and secrete mucus/CO 3 materials Bispira bunnea sabellid worm

9. Polychaete Anatomy

10. Polychaete Anatomy (cross section)

11. Polychaeta Amphitrite

12. Polychaeta Lugworm (Arenicola sp)

13. Polychaeta

15. Clade Siboglinidae (Phylum Pogonophora) Ridgea sp Riftia pachyptila

16. Giant tube worms (Vestimentifera) Riftia pachyptila trophosome

17. Polychaete Reproduction Dioecious Trochophore larvae Some species develop specialized segments containing gametes –Epitokes –Segments are released and gametes burst out

18. Polychaete Asexual Reproduction Epitokes are essentially buds Clues to ancestral origin of segmentation –Segmentation may have been derived from incomplete budding processes

19. Class Oligochaeta

20. Oligochaete Anatomy

22. Seta: a.k.a. Bristles

23. Oligochaete Excretory System

24. Oligochaete Nervous System

25. Oligochaete Nerve Cord

26. Oligochaete Reproduction

27. Oligochaete Development For terrestrial oligochaetes, development is direct without any larval forms Some aquatic oligochaetes retain a trochophore-like larval stage

28. Common Terrestrial Oligocheates: Earthworms Octagonal-tail wormOctagonal-tail worm (Dendrobaena octaedra)Octagonal-tail wormOctagonal-tail worm Red marsh wormRed marsh worm (Lumbricus rubellus)Red marsh wormRed marsh worm Dew-worm or nightcrawlerDew-worm or nightcrawler (Lumbricus terrestris)Dew-worm or nightcrawlerDew-worm or nightcrawler Pink soil wormPink soil worm (Aporrectodea rosea)Pink soil wormPink soil worm Canadian wormCanadian worm (Aporrectodea tuberculata)Canadian wormCanadian worm Pasture wormPasture worm (Aporrectodea turgida)Pasture wormPasture worm Woodland white wormWoodland white worm (Octolasion tyrtaeum)Woodland white wormWoodland white worm Redworm (Eisenia fetida )

29. Quick and Easy Earthworm Morphology Guide Aporrectodea turgidaLumbricus rubellus Morphology Number & location of GTs and TPs, location & shape of clitellum Ecology Location of burrows

30. Aquatic Oligocheates

31. Class Hirudinea

32. Hirudo medicinalis

33. Phylum Sipuncula ~250 species Trochophore larvae

34. Sipunculan Internal Structures

35. Phylum Echiura ~140 species Closed circulatory system Trochophore larvae Echiurus sp

36. Phylum Echiura Bonellia viridis

37. Echiuran Anatomy

38. Oddities Sex determination & dimorphism in echiurans