The morphology of the female reproductive structures of Penonyx excavatus (Oligochaeta)
Perionyx excavatus (Oligochaeta) is a vermicomposting earthworm of which little is known regarding its reproductive strategies. This is a second paper by the authors on the morphology of the reproductive structures in an attempt to reconcile the scanty and confusing literature on this topic and to investigate the possibility of self-fertilization The investigation was done by examining the gross anatomy and histology, using scanning and transmission electron microscopy. The female reproductive system consists of three pairs of spermathecae in segments seven, eight and nine. Each spermatheca consists of one ampulla and four sessile diverticula. The spermathecae open separately but midventrally in the intersegmental groove anterior to the segments in which they occur. One pair of ovaries is found in segment 13. The ova are released into the body cavity and are collected by the two ciliated ovum funnels, also in segment 13. The two short oviducts leading from the ovaries, join into a common oviduct. The common oviduct opens into the female opening, which is situated midventrally, anterior to the ring of body chaetae on segment 14.