1. Phyla Platyhelminthes, Nemertea, Nematoda, Annelida, Sipuncula, & Echiura The Worms

3. I) Worms A)Bilateral Symmetry B)True organs & organ systems C)All have complete digestive tracts except for flatworms D)Mesoderm (middle cell layer) 1) Muscles, Reproductive Organs, & Other Organs

5. II) Phylum Platyhelminthes A)AKA: Flatworms B)~20,000 species C)Central Nervous System 1)Brain 2)Simple Nerve Aggregation D)Turbellarians 1)Free-swimming carnivores

6. II) Phylum Platyhelminthes E)Flukes (trematodes) 1)Parasites: Feed on blood, intestines, tissues F)Tapeworms (cestodes)

9. III) Phylum Nemertia A)AKA: Ribbon Worms B)~900 known species C)Primitive circulatory system D)Proboscis 1)Long, flesh tube used to entangle prey 2)Predators E)Longest invertebrate on Earth 1) Over 100 feet long

10. IV) Phylum Nematoda A)AKA: Roundworms B)10,000 – 25,000 known species 1)Estimated to be ½ million species 2)Undercounted C)Live in rich sediment or are parasitic D)Hydrostatic skeleton

12. V) Phylum Annelida A)AKA: Segmented Worms B)~20,000 known species C)Segmented D)Gut lies in cavity known as coelom E)Hydrostatic skeleton F)Closed Circulatory System G)Respiration 1)Through skin – smaller 2)Gills – larger

13. V) Phylum Annelida H)Class Polychaeta 1)AKA: Bristle Worms 2)Parapodia: movement 3)Setae: sharp bristles 4)Predators & Suspension Feeders

14. V) Phylum Annelida I)Class Oligochaetes 1)AKA: Earthworms & Relatives 2)Suspension Feeders 3)No Parapodia

15. V) Phylum Annelida J)Class Hirudinea 1)AKA: Leeches 2)Suspension Feeders 3)Suckers on each end 4)No Parapodia

17. VI) Phylum Sipuncula A)AKA: Peanut Worms B)~320 known species C)Unsegmented D)Retractable tentacles for feeding (deposit feeders)

18. VII) Phylum Echiura A)AKA: Spoon Worms B)~135 known species C)Unsegmented D)Non-retractable proboscis (deposit feeders)