Setae
- The setae help in locomotion and are most important character for identification.
- Except for the first and last segment all other body segments have tiny bristles or spines.
- Their number and arrangements are either lumbricine (generally 8 per segment in pairs on ventral and latero-ventral side) or perichaetine (numerous and arranged in a ring on the segment with a large or small break in mid-dorsal and mid- ventral regions).
|
|
|||
|
Fig: View of different arrangement of setae: A. Lumbricine arrangement; B. Perichaetine arrangement |
||||