GONADOTROPIC MITOGENIC ACTIVITY OF THE OPTIC GLAND OF THE CUTTLEFISH,SEPIA-OFFICINALIS, DURING SEXUAL-MATURATION

A cytological study was carried out on the main cells of the optic gla nd of male and female Sepia officinalis L. during sexual maturation (a nimals collected in the field). The results were correlated with exper imental data on the mitogenic action of optic gland extracts collected during a period of secretory activity. The main cells of the optic gl and show some of the features of protein-secreting cells, although the y are not very pronounced. The secretory activity of the cell was foun d to be correlated with a peak of mitogenic activity occurring in Sept ember/October in the case of the males and in November in that of the females. The secretion of gonadotropic mitogenic factor varies through out the sexual cycle of Sepia officinalis. This activity is correlated with a rapid multiplication of spermatocytes and spermatogonia in the males, whereas in the females it corresponds to previtellogenesis.