SEASONAL CHANGES IN THE CYTOLOGY OF THE OVARY AND OF THE PITUITARY GLAND OF THE GOLDFISH

Abstract

Goldfish ova undergo maturation from November until the following July. Seasonal changes in the maturation and resorption of follicles were correlated with changes of the area of pituitary basophils in sagittal sections. Resorbing ova are found throughout the year but are more abundant at sexual maturity and particularly prominent in ovaries of fish which fail to spawn. Resorption is associated with a marked hypertrophy of the follicular granulosa and this layer is evidently responsible for the removal of egg contents. The cytology of the developing ova and of the hypertrophied granulosa of the resorbing follicle are described. The possible source of the ovarian hormones is discussed but the present study provides no evidence for the cells responsible for their production.