External Characters

(i) Form, shape, length, diameter, number of body segments and colour (usually colour changes after preservation).

(ii) Type of prostomium prolobic, epilobic, zygolobic, tanylobic.

(iii) Number of annuli/segment at pre and post clitellar region.

(iv) Number of segment from which dorsal pore begins.

(v) Type of setal arrangements (perichaetine or lumbricine) distances between the pairs and setal formula.

(vi) Position of spermathecal pores, male pores, female pores and prostatic pores. Position of pores has to be observed in synchronization of setal arrangement.

(vii) Structure of pineal setae: to observe their structure, remove the pineal setae from the inner side of worm and mount on a slide in a drop of glycerine.

(viii) Genital markings viz., papillae, pits, tubercula pubertitus (may or may not be present).


Dorsal Pores

Female Pores

Genital Markings

Male Pore


Peristomium and Prostomium


Spermathecal Pores