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Vol. 41 No. 2, 2002
The Morphology of Gonadal Tissue and Male Germ Cells in the
Protandrous Black Porgy, Acanthopagrus
schlegeli
Jing-Duan
Huang, Mong-Fong Lee and Ching-Fong Chang*
Department
of Aquaculture, National Taiwan Ocean University, Keelung, Taiwan 202
Jing-Duan
Huang, Mong-Fong Lee and Ching-Fong Chang (2002) The morphology
of developing bisexual gonads and male germ cells in the protandrous
black porgy, Acanthopagrus schlegeli, is described using light and
electron microscopy. Conspicuous differences in struc- tural
characteristics were observed in the lobular structure in reproductive,
non-reproductive, and regressed testicular tissues. Testicular tissue
showed significant alternations and disintegrated in the sex-changing
gonad. Sertoli cells contained mitochondria, free ribosomes, Golgi
complexes, and endoplasmic reticulum. Cyto- plasmic processes of
Sertoli cells formed cysts which contained synchronous germ cells
(spermatogonia, spermtocytes, spermatids, and spermatozoa).
Mitochondria, endoplasmic reticulum, oil droplets, and free ribosomes
were observed in Leydig cells. Perinuclear cement or nuage was found in
spermatogonia. Spermatogenesis and spermiogenesis are described in male
germ cells. Decreased cell size, an increasing nuclear- cytoplasmic
ratio, and a reduced number of mitochondria were characteristics
observed during development of spermatogonia to spermatids.
Intracellular movements (diplosome, mitochondria migration, loss of
cytoplasm, and nuclear rotation and depression) and structural changes
(chromatin, formation of flagella) ap- peared during spermiogenesis. A
cytoplasmic bridge was found in spermatocytes and spermatids. Intercel-
lular junctions (at least gap junctions and tight junctions) appeared
in Sertoli cells which were adjacent to other Sertoli cells or germ
cells. These data provide important information for the further study
of ultra- structural changes in bisexual gonads during the controlled
and natural sex change in the protandrous black porgy.
Key words: Gonadal
development, Leydig cell, Sertoli cell, Sex change, Ultrastructure.
*Correspondence: Tel: 886-2462-2192 ext. 5209. Fax:
886-2-2462-1579. E-mail: b0044@mail.ntou.edu.tw
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