Phylum Nematoda Round worm 12 000 species 100

Phylum Nematoda • Round worm • 12, 000 species – 100, 000 possible • Cylindrical body • Longitudinal muscle • Pseudocoelomate • Complete digestive tract • Found everywhere • Parasites of nearly all plant and animal 3

4

Pseudocoelomate Ectoderm Mesoderm Endoderm 5

Lip 7

9

Pharynx 11

14

15

17

19

21

22

Ovaries 23

Oviduct 24

Uterus 25

Vagina 26

27

28

29

30

32

33

Enterobius vermicularis • Pin worm • Adults live in colon and ileum • Egg spread – Fecal oral route – airborne 34

Hookworm • • Anterior end hook Necator americanus Ancylostoma duodenale Feed on blood at intestinal wall • Cause anemia 36

Cutaneous Larval Migrants • Filariform larva 37

Wuchereria bancrofti and Brugia malayi • Lives in lymphatic system • Obstruct lymph to cause swelling – Elephantiasis 38

Elephantiasis 39

Gnathostoma spinigerum • Accidental host (human) 40

Loa loa • Eye worm 41

Dirofilaria immitis • Dog heart worm 42

44