Gametogenesis and reproduction in Hormogaster elisae (Oligochaeta, Hormogastridae)

The gametogenesis of the earthworm Hormogaster elisae, an endemic species of central Spain, was studied over a 12-month period. The ovaries, seminal vesicles, male funnels, and spermathecae of 156 specimens were removed by dissection. Microscopic analysis of these organs allowed the study of the gametogenic cycle, and provided information on copulation method and reproductive cycle. Individuals of H. elisae have two pairs of spermathecae, the posterior of which is more important for the storage of sperm. In summer, the earthworms enter quiescence, and oogenesis and spermatogenesis are interrupted. The gametogenic processes occur mainly during autumn and winter. Ovules are produced during all months except August and September, and the spermathecae contain sperm over the full 12-month period. There is a reproductive peak in spring, when most ovules are produced and the clitellum is most developed.