Development of Ovarian Tissue and Female Germ Cells in the Protandrous

of ovarian tissue and female germ cells in the protandrous black porgy, Acanthopagrus schlegeli (Sparidae). Zoological Studies 47(3): xxx-xxx. The morphology of developing bisexual gonads and female germ cells in the protandrous black porgy, Acanthopagrus schlegeli (Sparidae), is described using light and electron microscopy. The central (ovarian) cavity and sex differentiation were observed in the differentiating gonad at 5 mo of age. Testicular tissue was the main tissue in the gonad with a small portion of ovarian tissue limited to the area around the central cavity and main blood vessel. Oogonia which were grouped as cell nests in the germinal epithelium and oocytes appeared during the period from the differentiated gonad to the 1st spawning period. Ovarian lamellae, containing oogonia and primary oocytes, developed towards the central cavity after the 1st spawning season. The testicular tissue regressed but ovarian tissue developed during the non-spawning period in 1+- and 2+-yr-old fish. Female germ cells were classified into oogonia, chromatin-nucleolus oocytes, perinucleolar oocytes, cortical alveolar oocytes, vitellogenic oocytes, and maturing oocytes. Only primary oocytes, the most advance