CLASSIFICATION OF POLYNOE
PHYLUM :- ANNELIDA (Metamerically segmented, coelomate and laterally symmetrical. )
CLASS :- POLYCHAETA (Many setae, clitellum absent. )
ORDER :- ERRANTIA (Free-swimming or burrowing, pharynx protrusible, provided with jaws and teeth. )
GENUS :- Polynoe
It is found in Europe and U.S.A. (South Carolina to Massachusetts).
HABIT AND HABITAT
Polyone is a bioluminescent, carnivore, marine, errant polychaete, hidden under stones near tide lines
GENERAL CHARACTERSTICS OF POLYNOE
- It is an allied form of Aphrodite consisting of a short body with parallel sides. The body shows considerable degree of dorso-ventral compression.
- Anterior end is distinguished into head, which bears three tentacles.
- Pharynx is protrusible containing teeth at protruded end. They eat one another.
- Some posterior parapodia bear setae.
- Certain parapodia instead of cirri bear broad, flattened and scale-like elytra, which constitute protective covering to the back.
- Elytra do not contain setae and have rich nerve supply.
- Elytra are bioluminescent and the illuminating elytra are easily cast off when disturbed or elytra are shed off to deceive the enemy.
- Utility of the casting off of elytra is not known but throwing of it frequently may be to deceive the enemies. This is protective device.
- Fertilized ova and embryos adhere to masses under each elytra.
The animal contains elytra without setae and all above features and hence it is Polynoe.