FLATWORMS

1. FLATWORMS Výukový materiál OR 03 - 67 Tvůrce: Mgr. Alena Výborná Tvůrce anglické verze: ThMgr. Ing. Jiří Foller Projekt: S anglickým jazykem do dalších předmětů Registrační číslo: CZ.1.07/1.1.36/03.0005 Tento projekt je spolufinancován ESF a SR ČR

2. FLATWORMS • A tape body • The first animals with an excretory system • A digestive system with one orifice • Parasites - they receive food by whole surface of the body

3. FLATWORMS - DUGESIA • They live freely, the most often in water and humid soil • The size from some mm to 30 cm • They are predators • A mouth orifice on the abdominal side of the body • Organs of smell and sight • A big ability of regeneration • Dendrocoelum lacteum

4. A small guide of flatworms according to the head ends: • Dugesia gonocephala • Dugesia tigrina • Crenobia alpina • Dendrocoelum lacteum • Dugesia lugubris • Polycelis felina

5. Dendrocoelumlacteum – a body structure • Touch lobes • Eyespots • A nerve system • A digestive system • An excretory system • A mouth

6. FLATWORMS- FLUKE WORMS • Parasites • They parasitize on skin, gills of fish, in an oral cavity, in an intestine, in bile ducts of liver, in vasal capillaries • They eat blood and disturbed tissues • Some of them live only on one host • The others change the host during the evolution

7. FLATWORMS – FLUKE WORMS • Cat liver fluke • Eggs leave with excrements of pastured cattle • If they get into the water, eyebrowed larvae come out • The larva must find an intermediate host – a water slug (e.g.a great pond snail) • After a certain time the larva leaves the intermediate host • It gets on wet grass a cyst • The host eats down the grass (e.g.a sheep) the end of the evolution

8. FLATWORMS – FLUKE WORMS • Schistosoma • A dangerous parasite • In tropics and subtropics • They screw in a body of the host • They get into the blood and go into a bladder, liver, bone marrow and a brain by blood • They cause serious inflammations • Illness – bilharzia (in rice fields)

9. FLATWORMS – FLUKE WORMS – an evolution of schistosoma • A larva • An egg • A larva

10. FLATWORMS – TAPEWORMS • Parasites • They live in bodies of vertebrates • A body structure: • A scolex + hooks or suckers • A neck • Flat proglottis – they get longer and larger to the end • They do not have a digestive system • In each proglottis there are male and female genitalia

11. A beef tapeworm

12. FLATWORMS – TAPEWORMS • The last proglottis contain fertilized eggs • Evolution takes place in a few intermediate hosts • Larvae are set in muscles, liver or brains of vertebrates • Cystycersus = a rest stadium, a larva

13. FLATWORMS – TAPEWORMS An evaluation of a pork tapeworm • A cystycersus • A larva • An egg • Proglottis with eggs

14. FLATWORMS – TAPEWORMS • Pork tapeworm • The most frequent human tapeworm • Cysticersus are in muscle of pigs • Beef tapeworm • Cysticersus are in beef meat • Flea tapeworm • The most frequent dog tapeworm • Cysticersus are in bodies of fleas

15. REVISION: • 1) How many orifices does a digestive system of flatworms have, if they have a digestive system? • 2) What system do we meet by flatworms for the first time? • 3) All flatworms are distinguished by a big…. • 4) How is the intermediate host of a cat liver fluke called? • 5) How is the disease caused by a schistosoma called?

16. Source: • DOBRORUKA, Luděk J. Přírodopis pro 7. ročník základní školy. 1. vyd. Praha: Scientia, 1998, 152 s. ISBN 80-718-3134-4