Transcript Phylum Platyhelminthes BIO 2215 Oklahoma City Community College Dennis Anderson Phylum Platyhelminthes • • • • • Flat worms Triploblastic Acoelomate Bilateral symmetry Hermaphroditic – Monoecious • One opening for digestive system • Paired lateral nerve cords &

Phylum Platyhelminthes
BIO 2215
Oklahoma City Community College
Dennis Anderson
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Phylum Platyhelminthes
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Flat worms
Triploblastic
Acoelomate
Bilateral symmetry
Hermaphroditic
– Monoecious
• One opening for digestive
system
• Paired lateral nerve
cords & cerebral ganlion
• Flame cells
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Uniramia
Echinodermata
Chordata
Lophophorates Chelicerata
Crustacea
Protochordates
Arthropoda
Annelida
Hemichordata
Other
pseudocoelomates
Nematoda
Mesozoa
Sarcomastigophora
Ciliophora
Apicomplexa
Microspora
Mollusca
Nemertea
Platyhelminthes
Ctenophora
Cnidaria
Placozoa
Porifera
Myxozoa
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Acoelomate
Ectoderm
Mesoderm
Endoderm
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Phylum Platyhelminthes: Class Turbellaria
Acoelomate
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Pseudocoelomate
Ectoderm
Mesoderm
Endoderm
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Coelomate
Ectoderm
Mesoderm
Endoderm
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Nervous System
Lateral nerve cord
Cerebral ganglion
Connectives
Eye spot
Auricle
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Brain
Auricle
Cerebral
ganglion
Paired
nerve cords
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Excretory System
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Class Turbellaria
• Eye spots
• Ciliated surface
• Regenerate if cut in
two
• Most are free-living
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Turbellaria
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Class Trematoda
• Flukes
• Parasites
• Holdfast devices
– Most
• Complex life cycle
• Intermediate host
– Animal with juvenile stage
• Definitive host
– Animal with adult stage
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Clonorchis sinensis
Oral sucker
Intestine
Uterus
Yolk gland
Ovary
Seminal
recepticle
Testes
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Clonorchis sinensis
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Chinese liver fluke
50 million people
Cirrhosis of liver
Diarrhea
Edema
Pain
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Fascioloa hepatica
• Sheep liver fluke
• Sheep, cattle and
man
– Weight loss
• Eat vegetation with
metacercaria
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Life Cycle of the Sheep Liver Fluke
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Fasciolopsis buski
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Intestinal fluke
10 million people
Man and pigs
Hemorrhage and
abscesses of small
intestine
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Paragonimus westermani
• Lung fluke
• Carnivores, pigs,
rodents and man
• May be fatal
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Schistosoma
• Blood flukes
• 200 million people
• 1 million deaths/year
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Life Cycle of a Schistosome Fluke
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Schistosome
• Cercaria have forked
tail
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Swimmers Itch
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Class Monogenea
• One host
• Ectoparasites
– Mainly fish
• Opisthaptor
– Attachment to host
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Class Cestoidea
• Tape worms
• No digestive system
• 40 feet long
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Scolex
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Proglottid
Testes
Uterus
Vas deferens
Seminal receptacle
Ovary
Yolk gland
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Pork Tapeworm (Taenia solium)
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Taenia
saginata
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Life Cycle of the Broad Fish Tapeworm
Diphyllobothrium
latum
Source: Redrawn From Centers for Disease Control, Atlanta, GA.
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Dipylidium caninum
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Echinococcus granulosus
• Parasite of dogs
– Host
• Juveniles in sheep,
man and other
mammals
– Intermediate host
• Hydatid cyst
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Hydatid Cyst
• Cysticercus
– Juvenile stage
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Ecinococcus granulosus
• Adult stage in dog
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