1. Lecture: TAPEWORMS-Introduction to FLATWORMS

Question 1

Which systematic taxon does flatworms (PLATYHELMINTHES) belong to along with roundworms and arthropods?

Answer 1

Kingdom Animalia

Question 2

What are the classes of flatworms important in veterinary medicine?

Answer 2

1. Cestoda = Tapeworms 2. Trematoda (flukes)

Question 3

Description of flatworms, how to distinguish flatworm from roundworm?

Answer 3

1. flatworms flat, ribbon-like body : roundworms cylindrical tubular like body, 2. digestive system of flatworms is incomplete =simple GIT single opening both mouth and anus : roundworm have separate anus and mouth. 3. Flatworms have cilia for moving : roundworms wriggling their body

Question 4

Into which order are tapeworms important in veterinary medicine?

Answer 4

1. cyclophyllidea 2. pseudophyllidea

Question 5

morphological description of tapeworms,(Cestoda) highlighting differences between 2 orders: especially segments/proglottids and head?

Answer 5

segments: 1. cyclophyllidea-uterus filling whole segment, hermaphrodite both male and female, 2.pseudophyllidea-rosette-like-coiled uterus medially, either male or female,
proglottids: 1. cyclops. NO UTERINE OPENING-genital pore laterally, 2. pseudoph. media-ventrally located genital pore and uterine opening
HEAD: 1.rostrellum present or absent: 4round suckers, 2. 2 slot-like bothria

Question 6

Which order has no uterine opening and what does this mean/why is it important?

Answer 6

1. cyclophyllidea DO NOT have > continous egg production > release eggs in feces > higher infection rate

Question 7

Life-cycle pseudophyllidean parasites simply, its features: several intermediate hosts, cycle related to water, where larva lives and where adult tapeworm lives?

Answer 7

> larva is released only in water, free-swimming organism > when eaten by 1st. intermediate host copepod -larva developed another larval stage > infected copepod eaten by 2nd IH (suitable vertebrae) larva invades somatic tissue and transforms into elongated larva > when eaten by FH - can grow into adult cestode

Question 8

What is metacestode?

Answer 8

thin-walled, fluid-filled cyst : forms of cestode larvae

Question 9

what is protoscolex?

Answer 9

small tapeworm ‘‘heads’’ (protoscolices) grow from inside surface=juvenile scolex