Digestion of spermatophore contents in the female genital system of the hermaphroditic flatworm Dugesia gonocephala (Tricladida, Paludicola)

Abstract

In Dugesia gonocephala, unlike other planarians, the cells of the copulatory bursa fulfill both a secretory and phagocytic function. Enzymes are synthesized in the absence of a spermatophore and are secreted into the lumen of the bursa when a spermatophore is received from a partner. During the days following copulation, seminal material is engulfed by the cells through cytoplasmic protrusions that extend into the lumen of the bursa. This material disintegrates and, as a result, the cells are filled with phagosomes of different sizes 3-4 days after copulation. Sperm cells are also digested in phagocytic cells that line the proximal side of the vitellarian follicles. Upon arrival in the lumen of the sperm receptacles, sperms penetrate the surrounding epithelial cells.