1. Chapter 34 Section 2 Phylum Nematoda & Rotifera

2. Phylum Nematoda Roundworms (pseudocoelomates) Bilaterally symmetrical 1mm-120mm (4 feet) Digestive tract with two openings (mouth & anus) Cuticle- protective covering

4. Phylum Nematoda Most are parasites and more than 50 species are parasites in humans Common roundworm studied by scientists in developmental biology is C. elegans

6. Ascaris Genus of roundworm parasites that live in pigs, horses, and humans Feed on food in intestines of host Females produce 200,000 eggs per day

8. Hookworms Hookworm- intestinal parasite Have cutting plates that clamp onto the intestinal wall Feed on host’s blood Cause anemia Like Ascaris, hookworms release eggs http://animal.discovery.com/tv-shows/monsters-inside-me/videos/flesh-eating-hookworm.htm http://www.petsandparasites.org/dog-owners/hookworms

10. Trichinella Form cysts in muscle of host Found in undercooked meat Trichinosis- disease causes muscle pain & stiffness Farmers no longer feed meat to hogs and freeze meat

12. Other Parasitic Roundworms Pinworm- most common roundworm parasite in the USA School age children Does not cause serious damage Found in feces

14. Other Parasitic Roundworms Filarial worms- disease-causing roundworms that infect over 250 million people in tropical countries Causes elephantiasis- limbs become swollen and skin hardens and thickens http://animal.discovery.com/tv-shows/monsters-inside-me/videos/parasite-causes-elephantiasis.htm

16. Other Parasitic Roundworms Dogs & cats T. canis and T. cati Live in the heart and large arteries of the lungs Heartworm disease

18. Phylum Rotifera Rotifers Transparent, free-living animals that live in freshwater Cilia surrounds the mouth- helps sweep food in- algae, bacteria, & protozoa

20. Phylum Rotifera Food moves from mouth to mastax- muscular organ that breaks down food Food is absorbed then passes from intestines to cloaca- common hole which reproduction, digestion, and excretory systems empty

22. Phylum Rotifera Rotifer reproduction Parthenogenesis- unfertilized eggs develop into adult females Other eggs form into males and the males fertilize other eggs with sperm

23. REVIEW!!! Identify two characteristics of the Phylum Nematoda and the Phylum Rotifera. What is the name of the most common roundworm studied by scientists in developmental biology? What type of worm causes elephantiasis?