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?