This document summarizes the main characteristics of seven marine worm phyla: Nemertea, Nematoda, Chaetognatha, Pogonophora, Sipunculida, Platyhelminthes, and Annelida. Platyhelminthes includes flatworms like tapeworms and flukes. Annelida contains segmented worms like earthworms and marine polychaetes. These phyla vary in body structure from flattened to segmented. They also exhibit different feeding strategies such as parasitism, suspension feeding, and predation.

1. MARINE WORMS

2. Types of Marine Worms Phylum *Platyhelminthes – flatworms Phylum Nemertea – ribbon worms Phylum Nematoda – roundworms Phylum Chaetognatha – arrow worms Phylum Pogonophora – deep-sea tube worms Phylum Sipunculida – peanut worms Phylum *Annelida - segmented worms

3. Phylum Nemertea – ribbon worms

4. Phylum Nemotoda - roundworms

5. Phylum Chaetognatha – arrow worms

6. Phylum Pogonophora – deep-sea tube worms

7. Phylum Sipunculida – peanut worms

8. Phylum Platyhelminthes – flatworms Includes tapeworms, freshwater planaria, parasitic flukes Some parasites, many free-living predators and scavengers Can cause swimmer’s itch in people

9. Phylum Platyhelminthes – flatworms tapeworm planaria parasitic fluke

10. Phylum Platyhelminthes – flatworms Flattened Lack segmentation Bilateral symmetry – simplest organisms to have it Acoelomate – no body cavity

11. Phylum Platyhelminthes – flatworms Mouth and anus are same spot

12. Phylum Platyhelminthes - flatworms Central nervous system (simplest organisms to posess) – bunch of nerve cells (ganglion) and two nerve cords Light sensitive eyespots Three layers of cells

13. Phylum Platyhelminthes – flatworms Beginning of organ development No true respiratory, excretory system – diffusion through surface Sexual (and asexual) reproduction - hermaphrodites

14. Phylum Platyhelminthes – flatworms

15. Phylum Annelida – segmented worms Includes earthworm, leeches, marine polychaetes (bristle worms) Body divided into ring-like segments Thousands of species

16. Phylum Annelida – segmented worms

17. Phylum Annelida - Polychaetes Most common types of marine annelids Have external, paddle-shaped structures (parapodia) with chaetae or bristles external gills or appendages

18. Phylum Annelida – segmented worms Coelom – fluid-filled body space – between digestive tube and body wall

19. Phylum Annelida – segmented worms Hydrostatic skeleton – uses fluid in coelom – helps animal move One-way digestive tube - mouth and anus Bilateral symmetry

20. Phylum Annelida – segmented worms More developed organ systems: Digestive system Nervous system Circulatory system With hemoglobin to carry oxygen Closed – blood in veins, arteries and capillaries

21. Phylum Annelida – segmented worms

22. Phylum Annelida – segmented worms Many lifestyles: - burrow - swim - sessile - live in tubes

23. Phylum Annelida – segmented worms feeding strategies: Parasites - attach to other organisms and feed through suckers

24. Phylum Annelida – segmented worms feeding strategies: Suspension feeders – trap particles floating in water feather duster worm Christmas tree worms

25. Phylum Annelida – segmented worms feeding strategies: Deposit feeders – eat particles that have fallen to sea floor

26. Phylum Annelida – segmented worms feeding strategies: Predators – use “teeth” to grab prey

27. Phylum Annelida – segmented worms Nereis sp. – sandworm, clamworm used for bait