FLATWORMSVýukový materiál OR 03 - 67Tvůrce: Mgr. Alena Výborná

Tvůrce anglické verze: ThMgr. Ing. Jiří FollerProjekt: S anglickým jazykem do dalších předmětů

Registrační číslo: CZ.1.07/1.1.36/03.0005Tento projekt je spolufinancován ESF a SR ČR

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

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

A small guide of flatworms according to the head ends:

•Dugesia gonocephala•Dugesia tigrina•Crenobia alpina •Dendrocoelum lacteum•Dugesia lugubris•Polycelis felina

Dendrocoelum lacteum – a body structure

• Touch lobes • Eyespots• A nerve system • A digestive system• An excretory system• A mouth

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

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

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)

FLATWORMS – FLUKE WORMS – an evolution of schistosoma

• A larva• An egg• A larva

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

A beef tapeworm

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

FLATWORMS – TAPEWORMS An evaluation of a pork

tapeworm• A cystycersus• A larva• An egg• Proglottis with eggs

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

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?

Source:• DOBRORUKA, Luděk J. Přírodopis pro 7. ročník základní

školy. 1. vyd. Praha: Scientia, 1998, 152 s. ISBN 80-718-3134-4