Multicellular animals characterized by a flat, bilaterally symmetric body
Dorsoventrally flattened and solid (no body cavity)
Hermaphroditic, having both male and female reproductive organs in the same individual
Overall size varies greatly, some members are as small as 1 mm, and others may be 20 meters or longer
The classes Cestoda (tapeworms) and Trematoda (flukes) contain species parasitic to humans
Cestodes
Flat, segmented body with various length (several mm – several meters)
Hermaphroditic with each proglottid developing both male and female reproductive organs, and mature eggs developing in the most distal proglottids
No circulatory system
No digestive system
Microtriches – outward projections present in the tegument, similar to microvilli of our gut mucosal cells, increase the surface area for nutrient absorption, interdigitate with host microvilli
Cestodes are diagnosed by
Finding eggs or proglottids (diagnostic stage) in the feces
Genital pore: Pseudophyllidean - Ventral, in the midline; Cyclophyllidean - Lateral
Eggs: Pseudophyllidean - Operculated, gives rise to ciliated larvae; Cyclophyllidean - Not operculated, do not give rise to ciliated larvae
Intermediate host: Pseudophyllidean - 2; Cyclophyllidean - 1 or none
Apolysis: Pseudophyllidean - Anapolytic (proglottids are not shed off because they have uterine pore); Cyclophyllidean - Apolytic (proglottids are shed off because they do not have uterine pore)