Oogenesis and spermatogenesis in Nephelopsis obscura and Erpobdella punctata (Hirudinoidea: Erpobdellidae) with comments on their life cycles

Oogenesis and spermatogenesis in Nephelopsis obscura and Erpobdella punctata from Stephenson's Pond, Alberta, were examined during the reproductive season (May to October). In N. obscura, two cycles of oogenesis and spermatogenesis were recorded, the first in June and the second in October; however, it could not be unequivocally demonstrated that N. obscura is iteroparous, although the potential for this exists. In E. punctata, protandry occurred with one complete annual cycle of oogenesis and spermatogenesis. No evidence for iteroparity was found. The development of a clitellum was found to be an unreliable indicator of sexual maturity in both species.