Phyla Platyhelminthes, Nematoda & Annelida Flashcards
Phylum Platyhelminthes
“Flatyhelminthes” Flatworms
How is the flatworm similar to planula?
No body cavity
Only a digestive cavity
Acoelomate
Traits of Platyhelminthes
Acoelomate Bilaterally symmetrical Triploblastic (gastroderm, epidermis and mesoderm that forms mesenchymal parenchyma) Cephalization Protophridial tubules with flame bulb
Traits of parasitic lifestyle
- organs of attachment: hooks suckers
- complex life cycles: many hosts
- no digestive tract: diffuse across the body wall
- general reduction/elimination of circulatory, respiratory, locomotory & nervous systems
The classes of Phylum Platyhelminthes
Tubellaria
Trematoda
Cestoda
Protonephridia cells
“First” + “kidney” these cells aid in waste disposal
“Flame cells” start in the parenchyma and once water enters through the fenestration it gets pushed by the flamelike cilia through the tube and out the nephridiopore.
Characteristics of Class Turbellaria
Free-living Marine, freshwater & terrestrial Dorsallly flattened External surface is ciliated Hermaphrididic
Characteristics of Class Trematoda
Trematods are flukes
All parasitic with complex lifecyles aka multiple hosts and fast reproductive strategies (endoparasitic)
Most commonly transmitted from crustaceans
Where is memory stores in Turbellarians?
In the muscles not the brain
Function of the tegument in the Trematods?
Tegument forms a protective layer around the epidermis of the fluke so that it can survive the hosts harsh conditions (pH levels).
Characteristics of Class Cestoida
All parasitic (endoparasitic)
Tapeworms
No mouth, no digestive tract > absorbing all nutrients through its body cell wall from the host
Proglottids with reproductive structures in each
No true segmentation
Ecdysozoan phyla
In the worms (polyphyletic) Phyla Nematoda is part of the Ecdysozoans because they shed their elastic cuticle during growth in juveniles
Neurocysteriosis
5 million cases of tape worm larvae eating the human brain and inducing epilepsy
