PHYLUM PLATYHELMINTHES General characters of platyhelminthes 1 They

PHYLUM: PLATYHELMINTHES

General characters of platyhelminthes 1. They are soft bodied, unsegmented worms. 2. They show bilateral symmetry and dorsoventrally flat worms. 3. They show three germinal layers i. e. ectoderm, mesoderm and endoderm. 4. The parasite shows suckers or hooks or both for attachment to the host body. 5. They are the first animals to illustrate the development of organ system.

• Kingdom : Animalia • Phylum : Platyhelminthes • Class : Trematoda • Family : Schistosomatidae • e. g. : Schistosoma haematobium

Schistosoma haematobium (urinary blood fluke) is a species of digenetic trematode, belonging to a group (genus) of blood flukes (Schistosoma). It is found in Africa and the Middle East. It is the major agent of schistosomiasis, the most prevalent parasitic infection in humans. It is the only blood fluke that infects the urinary tract. Adults are found in the venous plexuses around the urinary bladder.

Kingdom : Animalia Phylum : Platyhelminthes Class : Cestoda Family : Taeniidae e. g. : Taenia saginata

Taenia saginata commonly known as the beef tapeworm. It is an intestinal parasite. Cattle are the intermediate hosts, where larval development occurs, while humans are definitive hosts harbouring the adult worms. An adult worm is normally 4 to 10 m in length. The body is white in colour and consists of three portions: scolex, neck, and strobila. The scolex has four suckers, but they have no hooks.

T. saginata does not have a digestive system, mouth, anus, or digestive tract. It derives nutrients from the host through its tegument