1. Phylum Ctenophore The comb jellies Less than 100 species Radial symmetry 8 rows of ciliary combs, that beat in waves

2. October 31 st, 2014

3. Phylum Platyhelminthes Flatworms

4. -20,000 species -flattened -bilaterally symmetry -central nervous system with simple brain -organ and organ system -some free-living -some parasitic—live in or on other organisms and harm them (flukes and tapeworms) planaria Flatworm s

7. Internal parasites Flatworms

8. scolex Worm body tapeworms Flatworms

9. Phylum Nemertea Ribbon worms Look like long flatworms but more complex Complete digestive tract Circulatory system Proboscis –long fleshy tube used to entangle prey. 900 species-mostly marine. In all oceans, mostly shallow temperate waters

10. Ribbon worms

11. Phylum Nematoda Roundworms Rarely seen-25,000 sp. Some parasitic, some not Small, cylindrical bodies, pointed at both ends Live in sediments, eat bacteria

12. Phylum Annelida Segmented worms Phylum Annelida

13. Examples: polychaete worms, earthworm Bilateral symmetry Advanced marine worms Closed circulatory system Organ organization Larger ones have gills More advanced muscles system Segmented bodies Often live in tubes of mucus, protein, seaweed, mud, sand, shells 20,000 species

14. Symmetry Radial Bilateral

15. Segmented worms

16. Annelida Segments: a series of compartments Parapodia: each segment has flattened extensions Setea: stiff hair-like projections. Project from parapodia and are connected to internal muslces. Allow for contractions and movement.

17. Annelida