Histological study of general structure and mechanisms of secretion of the pedal mucus glands in the snail Lymnaea auricularia (L.).

Abstract

General histological structure and mechanisms of secretion of the pedal mucus glands in the snail Lymnaea auricularia (L.) are studied. The glands are composed of mucigenous units which include: mucigenous cells, mucigenous unions and mucigenous segments. These units are arranged in two zones: aggregation zone and distribution zone .The aggregation zone is mainly composed of mucigenous cells and mucigenous unions which are densely packed, while the distribution zone comprises loosely distributed units which are mainly formed of mucigenous segments. The mucigenous segments are motile parts separated either from mucigenous unions or from mucigenous cells .They move towards the surface epithelium of the foot. During this movement the segments undergo continuous changes in their structure and size. They, then, insert themselves between cells of the foot epithelium and finally discharge their components on the foot surface.