CLASSIFICATION OF CTENOPLANA
It is found along the coasts of Indo-China and Japan.
HABIT AND HABITAT
Ctenoplana is marine solitary, planktonic ctenophore.
GENERAL CHARACTERSTICS OF CTENOPLANA
- It is an aberrent ctenorhore fIrst discovered by Korotneff (1886) and later worked by Willey (1896), Dawyboff (1929) and Komai (1934).
- Body consists of flattened oval, central thick portion and two rounded, thin lobes in the sagittal plane.
- It measures 5 to 8 mm in the tentacular plane and coloured dorsally, mostly olive-green, brown or reddish. It reproduces asexually.
- Between the lobes of the anterior notch, there is a long tentacle giving irregular side branches. Main tentacle arise from base covered by tentacular sheath.
- There are 8 short comb rows of several plates connected to statocyst by ciliated furrows.
- Oral surface is characterised by everted pharynx, gastrovascular canal and peripheral network of gastrovascular canals.
- Anus present on left lobe.
- It reproduces asexually.
At the time of discovery of Ctenoplana and Coeloplana they were considered by some zoologists as connecting links between coelenterates and flatworms; but their structural details show that they are simply modifIed creeping ctenophores.
Besides above characters, main tentacle has several side branches and hence it is Ctenoplana.