Comparing Parasitic Worms
Tapeworm | Liver Fluke | Ascaris | Trichinella | |
Phylum | Platyhelminthes | Platyhelminthes | Nematoda | Nematoda |
Class | Cestoda | Trematoda | ||
How is this worm adapted to a parasitic lifestyle? | 1. Scolex with hooks for attaching to intestines of host
2. No mouth or digestive system – long flat body absorbs nutrients directly from host 3. Sensory receptors reduced or absent 4. Tegument (modified epidermis) protects against hosts digestive enzymes and immune system 5. Cuticle secreted by the epidermis also protects the worm 6. Hermaphroditic with well developed reproductive system capable of mating with each other and producing hundreds of thousands of eggs (no digestive system makes more room for eggs) 7. Proglottids capable of mating with each other, drop off when eggs ripe to infect intermediary host 8. Embryos form a bladder or cyst in intermediary host and wait to be eaten by primary host |
1. Oral sucker for attaching to host
2. tegument ot protect against hosts’s digestive juices and immune system 3. Larvae able to burrow through host tissues and use the circulatory system to travel throughout the body |
1. Female lays 200,000 eggs per day which pass out with feces
2. When new host eats contaminated food new infection occurs 3. Larvae able to burrow through host tissues and use the circulatory system to travel throughout the body |
1. Larvae form cysts in muscle tissue
2. When muscle eaten by predator, larvae are released into stomach to begin life cycle 3. Larvae able to burrow through host tissues and use the circulatory system to travel throughout the body |
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