22. Morphology, classification and life cycle of PSEUDOPHYLLIDA Flashcards
(28 cards)
What is the general body shape of Pseudophyllida?
DV flattened with tegument on surface
What are the main parts of the Pseudophyllida?
Scolex, neck, and strobila with proglottids
What is unique about the scolex of Pseudophyllida?
No suckers, but 2 longitudinal suction grooves – bothria
What is the function of the neck in Pseudophyllida?
Production of new proglottids
What is a strobila?
A linear series of proglottids
What are proglottids?
Hermaphroditic, egg-producing units budded from the neck region
What does strobilation refer to?
Asexual process forming segments
How do immature proglottids develop?
Maturate over time, eventually becoming gravid segments
How do gravid segments release eggs?
Through a uterine pore or detach entirely (rarely)
What is the main nerve center in Pseudophyllida?
A paired cerebral ganglion in the scolex
What is the role of the longitudinal nerve cords?
Extend along the body, connected by transverse branches
What type of excretory system do Pseudophyllida have?
Nephridial excretory system
What do the dorsal and ventral excretory canals do?
Transverse the entire strobila from scolex to last proglottid
What is the digestive system of Pseudophyllida?
Absent
What type of reproductive organs do proglottids contain?
Complete set of male and female reproductive organs
What type of fertilization occurs in Pseudophyllida?
Internal fertilization
Where does the uterus open in Pseudophyllida?
With a uterine pore
What is the structure of the uterus in Pseudophyllida?
Relatively long and coiled, sac-like
Describe the eggs of Pseudophyllida.
Unembryonated, with operculum and a button on other pole
What is a coracidium?
Ciliated embryo with characteristics of a hexacanth larvae (six hooklets)
What are the two shells of the eggs in Pseudophyllida?
Two thin shells
What are the three types of metacestodes in Pseudophyllida?
- Coracidium
- Procercoid
- Plerocercoid
What happens to the egg of Pseudophyllida when it reaches the water?
Embryonates and eventually hatches into a ciliated embryo – coracidium
What is the first intermediate host (IH) for Pseudophyllida?
Copepods
