1. Nematoda: Roundworms
First phylum to have the Complete digestive tract: mouth and anus
Pseudocoelomate: fluid filled between endoderm and mesoderm
Hydrostatic skeleton under pressure which means only one shape is possible (tapered hotdog)

2. Phylum Nematoda
Reproduction is usually sexual—females are generally larger than males.
Fertilization is internal, and a female can deposit 100,000 or more fertilized eggs per day.
The zygotes of most species are resistant cells capable of living in harsh conditions.
Hookworm

3. Roundworms
Pinworm
Ascaris: intestinal roundworm 1,000,000 cases in USA: 1.2 billion worldwide
Heartworm

4. Ascaris life cycle

5. Removal of Guinea Worm

6. nematodes http://www.youtube.com/watch?v=JBLemM3tzRM soil nematodes
lymphatic filariasis (elephantiasis) 1 billion worldwide

7. Annelida: segmented worms
Polychaetes, earthworms, leeches
Eucoelomate
Segmented body plan
Closed circulatory system
Protostome: opening in gastrula becomes the mouth

8. Annelida: key structures
Bristles on side
Aortic arches

9. leeches Fused segments to allow for blood storage
Blood thinner released to help sucking

10. http://www. youtube. com/watch
Earthworms in Australia
Earthworms are hermaphroditic. They fertilize each other with the clitellum secreting a mucus sack to collect the eggs and sperm. This sack is then placed into the ground until babies are developed.

11. annelids Polychaete: clamworm