Ultrastructural organization of seminal receptacle and sperm storage in Porcellio laevis Latreille (Crustacea: Isopoda Oniscidea)

摘要

The seminal receptacle of Porcellio laevis is a specialized region of the genital tract placed at the confluence of the oviduct with the ovary. In virgin sexually mature females the seminal receptacle wall consists of a monolayered epithelium lyingon a thin basal lamina and delimiting a narrow and anfractuous lumen. The cells are joined by cell junctions only in their apical portion and do not show marked secretory activity; numerous cells appear to undergo a partial or complete process of autophagy that preludes a remodelling of the seminal receptacle allowing it to receive and store a conspicuous number of spermatozoa. In mated females epithelial cells are characterized by wide intracellular spaces in their basal region, by an extensive development of smooth reticulum and by the release into the lumen of an abundant lipidic secretion. Some spermatozoa stored in the lumen are captured by pseudopodial-like protrusions produced by the epithelial cell surface and then drawn into cavities that formwithin the epithelial cells themselves. The spermatozoa stored in the seminal receptacle appeared to be well conserved and apparently able to fertilize even several months after insemination.