CLASSIFICATION OF EUNICE
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 :- Eunice
It is found in West Indies, Gulf of Mexico, Atlantic and Pacific oceans, Samoa and Fiji Island. The worm lives in the cracks and crevices of coral rocks throughout the year, except when swarming.
HABIT AND HABITAT
Eunice is a marine polychaete annelid famous for its swarming habits within three days of the fall of the July moon. Eunice viridis is the peculiar epitoke palolo worm of Samoa and Fiji Islands; swarms in October and November.
GENERAL CHARACTERSTICS OF EUNICE
- Commonly called as palolo worm. The body of the animal is differentiated into anterior sexless atoke and posterior sexual part, the epitoke.
- Pigmentation is brownish or yellowish.
- Fully mature, gonad-laden epitokes project from the burrow, detach from atokes and swim independently on the surface of the sea, while the atokes regenerate new epitokes.
- Body elongated with numerous segments; peristomium consists of two segments with 1 pair of cirri, 5 tentacles and a large palp.
- Gills begin on sixth segments.
- During swarming, the ocean becomes full of these frenzied creatures, swimming at high speed with intense agitation.
- After spawning, the epitokes sink to bottom.
- In some localities the ova and sperms are in such enonnous number that the surface of the sea turns into a thick soup.
Palolo worm exhibits remarkable example of periodic reproduction. Over 90% of the population breeds within a single two-hour period of the entire year. The major swarm occurs in November during last quarter of moon when the low tide is unusually low. On the night of breeding posterior half twists counter clockwise, breaks, comes to surface, bursts, sheds sperms and ova and disintegrates. The local population collects them by netting and make into thick soup which tastes like spinach. The natives can predict when palolo would swarm and watch the sea daily.
The animal has one-fourth body atoke, three-fourth epitoke and all above features and hence it is Eunice.