Platyhelminthes Characteristics
- Triploblastic, acoelomate
- Bilaterally symmetric
- Cephalization; with central nervous system
- Elongate, dorso-ventrally flattened
- Incomplete gut (gastrovascular cavity) or lack gut
- Free-living and parasitic forms
|
Class Turbellaria — Free-living Flatworms
Characteristics
- Free-living; mostly aquatic
- Epidermis ciliated
|
Fresh-water planarians, possibly Phagocata velata, KY
|
Brown Flatworm, Notoplana acticola, in tidepool, CA
|
Land Planarian, Bipalium kewense, a terrestrial flatworm native to SE Asia but widely introduced elsewhere; NY
|
Planarian, Dugesia sp., carbon-fed whole mount
See also labeled photo.
|
Planarian, Dugesia sp., stained cross-section (40x)
See also labeled photo.
|
|
Class Trematoda — Trematode Flukes
Characteristics
- Internal parasites with often complex life cycles
- Epidermis forms tegument
- Attach to host via oral and ventral suckers
|
Schistosome, Schistosoma japonicum; fresh-water snails are intermediate host and various vertebrates are definitive host; (stained whole mount).
|
Chinese Liver Fluke, Clonorchis sinensis, a human parasite that reaches maturity in the bile duct; stained whole mount.
See also labeled photo.
|
Sheep Liver Fluke, Fasciola hepatica, a parasite of sheep livers; other life stages found in snails.
See also labeled photo.
|
|
Class Cestoda — Tapeworms
Characteristics
- Parasites of vertebrate guts
- Epidermis forms tegument
- Attach to host via anterior scolex
- Trunk (strobila) greatly elongated, consists of numerous segmented proglottids
|
Dog Tapeworm, Taenia pisiformis, a common intestinal parasite of dogs and pigs
|
Dog Tapeworm,Taenia pisiformis, microscopic view of solex, proglottids.
See also labeled photo.
|
|
