Phylum Nematoda:Phylum Nematoda:The Round WormsThe Round Worms

•Over 80000 speciesOver 80000 species•Cylindrical Cylindrical pseudocoeloematespseudocoeloemates•Have effective Have effective hydroskeletonhydroskeleton and and musculaturemusculature•Inhabit aquatic areas. Inhabit aquatic areas. Most are parasitic.Most are parasitic.•Most reproduce sexually. Most reproduce sexually. Females can produce ~100,000 Females can produce ~100,000 eggs a day.eggs a day.•Tricininella spiralisTricininella spiralis causes causes trichinosistrichinosis in humans in humans from under cooked porkfrom under cooked pork•Parasite burrows into Parasite burrows into muscle tissue forming cystsmuscle tissue forming cysts

•HookwormsHookworms and and pinwormspinworms can parasitize digestive can parasitize digestive systemssystems•Others cause Others cause heartwormheartworm and and elephantiasiselephantiasis

Parasitic Nematodes:Parasitic Nematodes:

RoundwormRoundworm HookwormHookworm

HeartwormsHeartworms

Guinea Worms:Guinea Worms:

Elephantiasis Elephantiasis (Filarial worm)(Filarial worm)

Life Cycle of Filarial WormLife Cycle of Filarial Worm

TrichinosisTrichinosis

Phylum NemertinaPhylum Nemertina• Similar to flat wormsSimilar to flat worms• Inclide proboscus wormsInclide proboscus worms• Acoelomate, but have functioning digestive tractAcoelomate, but have functioning digestive tract• Also have a funtioning blood vascular system Also have a funtioning blood vascular system