Cestodes
tapeworms
Pseudophyllidean
false cestodes
cestodes characteristics
- tape-like, ribbon-like
- segmented
- bilaterally symmetrical
- hermaphrodite
Parts of Cestodes
- with scolex (attachment organ)
- neck (organ for growth)
- strobila (chain of segments developed from the neck)
Proglotid
segment
Proglotids
Immature
- Contains the undeveloped reproductive organs
Mature
- Contains the complete functional set of male and female reproductive organs
Gravid
- Contains the well developed uterus and egg
*** Apolysis
- detachment of gravid segment from the adult worm; eggs are released
*** Pseudoapolysis
- the last segment gradually disintegrates
Cyclophyllidean
true cestodes
Pseudophyllidean
Scolex
Strobila
- Spoon-shaped w/ slit like sucking grooves (bothria)
- Anapolytic (not shedding segments)
Pseudophyllidean
Uterus
Uterine pore
- Coiled in rosette form
- Found in the median Ventral surface
Cyclophyllidean
Scolex
Strobila
Quadrate with 4 cup-like suckers (w/ or w/o rostellum)
Apolytic (shedding segments)
Cyclophyllidean
Uterus
Uterine pore
Coiled in diff. shapes & patterns
No uterine pore
Pseudophyllidean
Genital pore
Egg
- centered
- oval; operculated; immature
Pseudophyllidean
Larval stage
IH
- Coracidium; procercoid; plerocercoid or sparganum
- 2
Cyclophyllidean
Genital pore
Egg
- found in lateral margin
- spherical; non-operculated, embryonated
Cyclophyllidean
Larval stage
IH
- cysticercoid; cysticercus; hydatid
- 1
Diphyllobothrium latum
common name
Broadfish tapeworm
D. latum
Ova
- oval with operculum
- 40-60 um
D. latum
Adult:
- Measures 1-30 feet long with 3000-4000 proglottids
D. latum
scolex
- spoon shaped with bothria
- sucker groove
D. latum
Proglottids
with coiled uterus (rosette)
D. latum
infective stage
Pleroceroid larva/sparganum
D. latum
MOT
Ingestion
