Type Nemathelminthes

1. Type Nemathelminthes

2. Type Nemathelminthes

~24 000 species
Free-living and parasitic
80 mcm – 8 m
Bilateral simmetry

3.

Unsegmented body
Schizocoel – body cavity
Sexual dimorphism
No respiratory or circulatory system
Excretory system – protonephridia/skin
glands/none
• They have anus (first time in the world history)

4.

5.

6. Class Gastrotricha

• 160 species. 1-1,5 mm. Live in fresh water
• Ciliated epithelium on their ventral side
• They are believed to be intermediate between
Turbellaria (freeliving flatworms) and
roundworms

7. Класс Nematoda

8. Human ascarid life cycle

9. Pinworm

• Only in humans!

10. Trichinella

11.

12. Whipworm

13.

14. Ankylostoma

15. Guinea worm

16.

17. Class Nematomorpha (hair-worms)

Parasites in insects
Very thin, up to 1,5 m long
No excretory system
1 nerve cord

18. Class Rotatoria

• ~1500 species, live in fresh water, 0,04-2 mm
• Corona with cilia on the head
• Some are sessile