Atresia of oocytes and ruptured follicles in Gobius giuris (Hamilton-Buchanan)

Abstract

The unspawned ripe oocytes and yolkless immature oocytes occurring in the spent ovary of Gobius giuris undergo atresia and form the corpora atretica. The resorption of the ripe oocytes appears to be due to an enzymatic activity of the follicle cells. The ruptured follicles also undergo resorption without forming a corpus luteum. The mesoadenohypophysis of the pituitary gland exhibits profound cytomorphological changes in its cyanophils during the reproductive cycle. Cytochemical studies indicate that a gradual accumulation of the acidophilic globules occurs within these cells until spawning and that these globules get depleted during subsequent stages. There is thus evidence that the resorption of the oocytes in the spent ovary is due to withdrawal of the gonadotropic hormone.