Phylum
PLATYHELMINTHES
Platy = Flat
Helminth = Worm
CHARACTERISTICS
• All show BILATERAL symmetry
• Posses three tissue (germ) layers:
1. Ectoderm 2. Mesoderm 3. Endoderm
• Most exhibit CEPHALIZATION.
• Majority Do NOT exhibit segmentation
TYPICAL
FLATWORMS
GETTING FOOD
• Some flatworms are free-living aquatic
worms. They obtain their food from cruising
around and feeding off of tiny living animals
or scavenging off of recently dead animals.
• Others are PARASITIC, they feed off of the
blood, tissue fluids or tissue cells of their
living host.
THREE CLASSES OF FLATWORMS
– Free Living Flatworms. Most common
example : Planaria
• TURBELLARIA
•TREMATODA – Parasitic Flatworms known as flukes, most
are less than one centimeter.
•CESTODA – Long Parasitic worms with hooks to attach to
intestinal wall of host.
TURBELLARIA - Planarians
TREMATODA - Flukes
Section of Moose Liver Infected with Liver Flukes
LIFE CYCLE OF BLOOD FLUKE
CESTODA - Tapeworms
TAPEWORM REMOVAL
DEWORMING
•Do You Have Pets?
•Do You Have Worms?
- Ever think you
have rice in your
stool/feces; but
you haven’t had
rice for a long, long
time?