Figure 4: Ovotestis of younger snails. (A) Acrosomal cap at the anterior end (arrow) of the nucleus in a developing spermatid. (B) Columnar Sertoli cells showing their cellular junction (white arrow). (C) The numerous microvilli at the anterior tip of Sertoli cells. (D) Sertoli cells showing their dividing stage with karyokinesis. The spermatid (black arrow) is inserted into the membrane of the Sertoli cell. White arrow indicates mitochondria. (E) Acinar portion showing acinar boundary, spermatocytes, spermatid and Sertoli cell. ad = acinar boundary; n = nucleus S = Sertoli cell; sc = spermatocyte; sd = spermatid.