CLASSIFICATION OF SYLLIS
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 :- Syllis
It is common in U.S.A., Woods Hole regions, Long Island Sound to Bay of Fundy.
HABIT AND HABITAT
Syllis is marine polycheate, known for its transverse fission and abundant in clear, shallow water among hydroids, mussels, tunicates and also in mud, sand and on shells.
GENERAL CHARACTERSTICS OF SYLLIS
- Animal measures approximately 30 cm in length and divisible into head and body segments.
- Anterior end constitutes head which is fonned by prostomium and peristomium.
- Prostomium contains 2 pairs of prostomial eyes, 3 pairs of prostomial tentacles and 2 grooved and jointed palps.
- Each parapodium consists of a long jointed notopodiaI cirrus and a well developed neuropodium with nonnal setae and cirrus. The notopodium is absent.
- Pharynx contains a conical jaw connected to poison gland by its duct.
- During breeding season, body is distinguished into anterior asexual (atoke) and posterior sexual (epitoke) regions.
- In Syllis hyalina, the epitoke region separates and regenerates independent head (either male or female).
- In S. ramosa lateral buds are fonned giving rise to much branched colony.
- Some of the lateral branches develop gonads and heads and later separate to become independent sexual adults.
Syllis shows extensive asexual reproduction by transverse fission.
the animal contains branched body segments and all above characters, hence it is Syllis.