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

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

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 Beef tapeworm Flea 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