VPA 211: General Veterinary Parasitology and Helminthology (3+1)

INTRODUCTION

 

Characters of subclass: Digenea

• Trematode is derived from the Greek work which means worms with holes
• Trematodes are dorsoventrally flattened flukes that are slender and leaf like or possess fleshy bodies.
• Absence of body activity (Acoelomate)
• Cuticle or tegument may be smooth or spiny.
• Parasites of alimentary canal or associated organs or in blood vessels.
• Most are hermaphrodite except schistosomes.
• Life cycle is complex and indirect.
• Organs of attachment include an anterior sucker known as oral sucker placed at the anterior end of the body and the ventral sucker also known as acetabulum at the anterior third of ventral surface, but position varies  from species to species or may be absent, for example in liver flukes and lancet flukes, the acetabulum is at the anterior third of the ventral surface while in amphistomes it is located at the posterior end.