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Worms. Three main Phyla Phylum Platyhelminthes - flatworms Phylum Nematoda – roundworms Phylum Annelida – segmented worms. Phylum Platyhelminthes. Flatworms Planaria, tapeworms, and flukes are examples Parasites and free living Planaria = free living Tapeworm + flukes = parasites.
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Worms • Three main Phyla • Phylum Platyhelminthes - flatworms • Phylum Nematoda – roundworms • Phylum Annelida – segmented worms
Phylum Platyhelminthes • Flatworms • Planaria, tapeworms, and flukes are examples • Parasites and free living • Planaria = free living • Tapeworm + flukes = parasites
Tapeworms • Parasites • Have body sections • Long – extend the length of the digestive system • Scolex = head • Contains suckers and hooks • Primitive – lack some body systems
Earthworm External Anatomy mouth Body segments clitellum anus
Phylum Annelida • Segmented worms • Earthworm and leeches are examples • Segmented body parts • Closed circulatory system • Mouth and an anus separate
Digestive System – Earthworm “alimentary tract” esophagus crop intestine pharynx prostomium mouth gizzard
Leeches leech