Classification of Phylum Platyhelminthes

Phylum :-  Platyhelminthes

Characters :- 

(i) Body bilaterally symmetrical & dorsoventrally flattened.

(ii) Digestive system had a single opening or mouth, that leads to a well developed gastrovascular cavity absent & anus absent.

Class :- Tubellaria

Characters :-

(i) Turbellarian are mainly free living, aquatic, but there are some terristrial sp.

(ii) Hermaphrodite, with internal fertilization.

Example :- Planeria (free living)

Fig :- Planeria

Fig :- Planeria anatomy

Class :- Trematoda

Characters :-

(i) Body cylindrical or leaf shaped & parasitic.

(ii) Body is covered by cuticle, which provides protection against host enzyme action & defence mechanism.

Examples :- Fasciola; Schistosoma; Aspidogaster;

Fig :- Fasciola

Fig :- Schistosoma

Fig :- Aspidogaster

Class :- Cestoidea

Characters :-

(i) Endoparasitic helminth, whose body is covered by a syncytial tegument.

(ii) Organs of attachment in the form of hooks & suckers are present.

Examples :- Taenia; Echinococcus;

Fig :- Taenia

Fig :- Echinococcus