External Apertures of Earthworm - QS Study
QS Study

Earthworms are nocturnal animals. They lie in the burrows during the day and come out at night for food. Earthworm leave the burrow only during the rainy season when their burrows are flooded with water.

(i) Dorsal pores: These are minute openings situated in the mid dorsal line in the intersegmental grooves commencing from the 10th segment. The co-elom communicates to the exterior through these pores and keep the body surface moist and free from harmful micro organisms.

(ii) Spermathecal openings: Three pairs of openings are situated ventrolat-erally in the intersegmental grooves between segments six and seven, seven and eight and eight and nine. These opening can be easily seen in mature worms.

(iii) Openings of oviduct: These are a pair of apertures lying close together on the ventral surface of the 14th segment.


(iv) Openings of Spermiduct: A pair of apertures are situated on the lowerside of the 18th segment.

(v) Nephridiopores: Numerous minute openings scattered on the body wall from 14th segment onwards.