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• TURBELLARIA – Free Living Flatworms. Most common example : Planaria

•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?