Spermatogenesis of Pheretima hawayana (Rosa) (Oligochaeta, Megascolecidae)

Abstract

?Spermatogenesis of Pheretima hawayana (Rosa) (Oligochaeta, Megascolecidae)?. The spermatogenesis of Pheretima hawayana (Rosa) was studied from an eminently cytogenetic point of view, leaving aside the classic histological techniques. Instead a previously tested and modified air-drying technique for Oligochaeta was employed. It was determined that there is a normal developmental process from protogonia and spermatogonia. These cells undergo 5 synchronous premeiotic mitosis (spermatogonic groups of 2, 4, 8, 16 cells and spermatocytes I of 32 elements) and the meiotic division (spermatocytes II and spermatids 64 and 128 elements respectively) leading to the formation of viable gametes. This last fact was confirmed by direct observation of the spermatozoons in the seminal receptacles or spermathecae.