1. 3 Phyla of Worms Platyhelminthes Nematoda Annelida Flatworms
Roundworms
Segmented worms

2. What worms have in common
Invertebrates
Narrow bodies w/o legs
HAVE tissues, organs, & organ systems
Bilateral symmetry
Head and tail ends
Brain
Sense organs – light and touch

3. Reproduction
Hermaphrodites – both male and female; usually don’t self- fertilize
Asexual – break into pieces and regenerate

4. Platyhelminthes
Planarians
Flukes
Tapeworms

5. Platyhelminthes Most are parasites – get food from host
Tapeworms live in digestive systems of host (many live in more than one host)
Flukes can live in host’s liver

6. Planarians Nonparasitic Free-living Scavengers Predators Eyespots
Smell
Inserts feeding tube
starts to break down food outside of body
sucks up the food
completes digestion inside body
then waste goes out the feeding tube

7. Nematoda - Roundworms Millions live in each square meter of soil.
Most are tiny and hard to see
Cylindrical bodies
Carnivores or herbivores
Others are PARASITES!
Have a digestive system like a tube, open at both ends.
A one-way digestive system: food broken down; absorbed; wastes eliminated.

8. Ascaris – intestinal roundworms

9. Annelida – Segmented worms
Earthworms
Sea-floor worms
Leeches

10. Annelids: Things in common
Segmentation
Live in almost all environments
Most burrow or live in tubes
“sit-and-wait” predators
Closed circulatory system

11. Earthworms Eat dead or decaying things
Skin needs to be moist to obtain oxygen
Good for soil:
Make it more fertile
Loosen it
Allow air, water, and plant roots to move through it

12. Worm dissection – what you should expect to see