Scanning electron microscopy of the prostomium and anterior segments of the earthworm (Lumbricus terrestris L., Eisenia foetida Sav.).

Abstract

A scanning electron microscopic study of the epithelium of the prostomium, anterior segments, mouth and pharynx was performed in Lumbricus terrestris L. and Eisenia foetida Sav. Numerous ciliated areas (number of cilia up to 800) identified as receptor organs, were found scattered on the prostomium and 1st segment. From the 2nd segment on, the number of organs decreased and they were arranged in several rows. Receptor organs small in size and number, were also found in the buccal and pharyngeal epithelium. The cilia of the sensory organs stuck out of holes of different sizes of the epithelial cuticle thickened by a supracuticular matrix. In addition, there were groups of about 5 cilia scattered below the epithelial cuticle. Each cilium lay in a narrow groove of the subcuticular surface of the epithelium characterized by an abundance of short thick microvilli protruding into evenly sized holes of the cuticle. The cilia appeared to be identical with those of solitary sensory cells.