1. PHYLUM NEMATODA
roundworms

2. CHARACTERISTICS Bilateral symmetry Wormlike body ( no kidding)
Pseudocoelom
Body covered with a cuticle
Many are parasitic
One way digestion

3. Examples Ascaris Trichina Worm Hookworm Pinworms
Have internal fertilization and development

4. Ascaris
An estimated 807-1,221 million people in the world are infected with Ascaris
Ascaris lives in the intestine and Ascaris eggs are passed in the feces of infected persons. If the infected person defecates outside (near bushes, in a garden, or field) or if the feces of an infected person are used as fertilizer, eggs are deposited on soil. They can then mature into a form that is infective. Ascariasis is caused by ingesting eggs. This can happen when hands or fingers that have contaminated dirt on them are put in the mouth or by consuming vegetables or fruits that have not been carefully cooked, washed or peeled.

6. Hookworms

7. Hookworm

8. Hookwoms

9. Trichina worms

10. Trichina life cycle
Trichinosis ( disease caused by Trichina worm) is spread when people eat meat with cysts ( larvae with protective covering)
After the covering ( the cyst) is digested in the stomach, the worms are released into the small intestine where they mature, mate, and the females release their larvae.
The larvae migrate to body muscles

11. The larvae encyst in the muscles of the body and feed off of the sugars.
Many animals carry the worm – most commonly – the pig
So beware of eating rare, undercooked pork.

12. Adaptations of parasitic worms:
A protective covering to resist digestion
Hooks and or suckers to stay attached to the intestines and resist flushing
Lack of a digestive system – they absorb already digested food
Expanded reproductive system – may are hermaphroditic