Study of pituitary gland development in Rutilus frisii kutum before hatching until adult stage

In this study، the morphology and organization of pituitary was investigated prior to hatching and at larval، juvenile and adult stages of the Rutilus frisii kutum. The eggs were kept in aquaria to study the stages before hatching. Fingerling reaching 1 gr of weight were maintained in laboratory condition for 5 month. Specimens larger than 1 gr up to adult stage were obtain either from fish culture center. In small specimens the whole head was processed that for larger once whole brain bearing hypophysis along with a small part of skull were after decalcification. All specimens were studied by histological methods. It was noticed that a day prior to hatching the hypophysis could be identifiable as a separate entity as comprised a part of ventral diencephalons. Adeno and Neurohypophysis could not be differentiated. Hypophysis was found to be partly separated and attached to the floor of diancephalon about seven days after hatching. An unbranched neurohypophysis was identified، pituitary gland was almost entirely unattached after 40 days and was seen to be stalked after 70 days. It was observed that the specimens of 25 gr as older had immense similarity with adult in structure and organization of hypophysis. The juvenile of later on (5 gram onwards) had the neurohypophysis. Penetrating in to adenohypophysis، particularly in to intermedia forming neurohypophysis lobe.