Determination of pituitary - gonad histology and hormonal status in relation with reproduction in common pandora (Pagellus erythrinus L., 1758)

In this work, changes in reproductive activity hormones and pituitary - gonad histology of common pandora (Pagellus erythrinus L., 1758) of a Sparid fish caught in Antalya Bay have been investigated. Because common pandora is protogynous hermaphrodit, 15 developmental stages, in which female, transitional and male characters develop, were determined. These stages were determined as inmature female, F1, F2, F3, F4, F5, F6 femaleness stages, T1, T2, T3 transitional and M1, M2, M3, M4, M5 maleness development stages. Transmission electron microscopy were used to investigate the fine structure of the gonads and pituitary gland of Pagellus erythrinus. Electron microscopic examination of oocytes, nucleus, nucleolus, the normal electron densty in these cells are contained endoplasmic reticulum, mitochondria, Golgi complex and numerous secretory vesicles. The spermatozoon of common pandora has a spherical head and an acrosome, a cone-shaped midpiece and a long tail. The midpiece houses a single mitochondrion. In this study, with histochemical methods of cell types in the pituitary gland of common pandora have been aimed to identification. Infundibulum region of the organ is cleared quite the anterior and posterior lobes. In the anterior lobe has reflected in the form of different staining properties the differents regional and cellular. The obtained samples, of the pituitary gland has been found round-oval shape. In the rostral pars distalis are especially located very dense asidofil cells and it constitutes dark-painted the region. There are many the number of basophilic cells in the proximal pars distalis. Pars intermedia is distinguished by the presence of colloid is not very clear boundaries. Painted in different ways small acidophils and large basophils reflect differences in hormone content in granules. Electron microscopic examination of pituitary are similar to cells endocrine secreting proteins features of the fine structure of this cell. Necessary for the hormone synthesis, a well-developed Golgi complex and membrane-located near, there are more intense mid-secretory vesicles a large number of round or oval. There are oval euchromatic nucleus.Hormon Changes in 17ß-estradiol (E2), testosteron (T) and 11-ketotestosteron (11KT) were examined in relationships with the changes in gonadosomatic index (GSI), vitellogenin concentration (Vg), according to the histology of the ovary and testis during the annual reproductive cycle of Pagellus erythrinus. According to the histology of the ovary during the annual reproductive cycle of common pandora, the highest value in the level of E2 reached during F5 stage. Vitellogenin levels fluctuated paralel to the GSI values. From level F1 to level F5 were seen that increase. GSI levels in males examined according to developmental stages and from M1 to M3 a linear increase was observed. GSI reached its maximum vales in M3. 11 KT levels were higher during M2 and M3 and its level was decreased during M4 and M5 stages. In males T hormone levels increased significantly during M2 and M3 stages. They then decreased after M4 stage. The cells that started secretory activity in pituitary, light and electron microscopic examinations, In addition to studies histological and electron microscopic of gonadal development, GSI%, E2, VTG, T, 11 KT hormone measurements according to the results obtained from our coasts of common pandora, from late April to beginnig of September, have been identified the realized reproduction.