• Applied Microscopy
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• v.40 no.1
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• pp.1-8
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• 2010

The ultrastructure of spermatogenesis and sperm in Chinese minnow, Rhynchocypris oxycephalus belonging to Leuciscinae was investigated by light and electron microscopes. The whitish testis was located between intestine and air bladder. The size of testis was major axis 2.3 cm, minor axis 6 mm. The testis contained numerous testicular cysts, and spermatogenesis was non-synchronized in these testicular cysts. In the case of spermatogonium, the nucleus was comparatively large ellipsoidal, and mitochondria showed a marked development. The size of primary spermatocyte was smaller than that of spermatogonia, and secondary spermatocyte was smaller than primary spermatocyte. The chromatin of spermatocyte was highly condensed according to their development. The nucleus with electron-dense was round shape. In spermiogenesis, flagella started to be formed and chromatin was more condensed. The mitochondria were rearranged in a middle piece. The sperm was formed by loss of cytoplasm. The head of mature sperm was a spherical shape and have not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm have not lateral fins.

• Applied Microscopy
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• v.39 no.3
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• pp.227-236
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• 2009

The ultrastructure of spermatogenesis and sperm in Coreoleuciscus splendidus, belonging to Gobioninae, Cyprinidae was investigated by light and electron microscopes. The testis was located between intestine and air bladder. The size of testis was major axis 1.8 cm, minor axis 3 mm. The testis of C. splendidus contained numerous testicular cysts, and spermatogenesis was non-synchronized in these testicular cysts. In May, the upper area of testis contained with other germ cells and sperm but the lower area of testis contained with matured sperm only. In case of spermatogonia, the nucleus was comparatively large spherical, and mitochondria showed a marked development. The size of primary spermatocyte was smaller than that of spermatogonia, and that of secondary spermatocyte was smaller than that of primary spermatocyte. The chromatin of spermatocyte was highly condensed according to their development. The nucleus with electron-dense was round shape. In spermiogenesis, flagella started to be formed and chromatin was more condensed. The mitochondria were rearranged in a middle piece. The head of matured sperm was a spherical shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm had not lateral fins and 7 outer coarse fibers.

• Applied Microscopy
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• v.39 no.3
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• pp.219-226
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• 2009

The ultrastructure of spermatogenesis and sperm in Cichlasoma managuensis belonging to Cichlidae was investigated by light and electron microscopes. The testis of C. managuensis contained numerous testicular cysts, and spermatogenesis was synchronized in these testicular cysts. In the case of spermatogonia, the nucleus was comparatively large ellipsoidal, and mitochondria showed a marked development. The size of primary spermatocyte was smaller than that of spermatogonia, and that of secondary spermatocyte was smaller than that of primary spermatocyte. The chromatin of spermatocyte was highly condensed according to their development. The nucleus with electron-dense was round shape. In spermiogenesis, flagella started to be formed and chromatin was more condensed. The mitochondria were rearranged in a middle piece. The sperm was formed by loss of cytoplasm. The head of mature sperm was a spherical shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm have lateral fins.

• Applied Microscopy
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• v.35 no.4
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• pp.74-83
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• 2005

The ontogeny of pollen wall in Panax ginseng was studied with transmission and scanning electron microscopy from early tetrad stage until pollen maturity. Initial indication of exine development is undulation of plasma membrane for the preparation of bacular mound. The first recognizable structure of the pollen wall is the cellulosic primexine which is formed outside of the plasma membrane while microspore tetrads are still surrounded by callose wall. As development proceeds, foot-layer and baculum differentiation, callose dissolution and exine formation were progressed. During this process, sporopollenin is deposited into the exine, and then endexine development was followed. The intine, innermost pollen wall layer, is developing form hypertrophic Golgi vesicles. The thickness of exine is very even on all along the pollen wall, but intine thickness of apertural region is thicker than that of nonapertural region. Mature pollen of ginseng is $20{\mu}m$ in size, tricolpate and shows fine reticulate sculpturing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.241-265
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• 1989

The purpose of present study is to describe the taxonomy and early life history of Korean pomfrets, genus Pampus. Egg diameter varied from $0.83\~1.27mm\;and\;1.05\~1.41mm$ in P. argenteus and P. echinogaster respectively. Larvae of P. echinogaster of 16.5 mm in total length has full number of fin rays and enter the juvenile period. The egg is matured at 185.0 mm in total length in P. argenteus and at 95.5 mm in total length in P. echinogaster. P. echinogaster is ossified from jaw bone at $8.5\~10.0mm$ in to1 length and followed by ossification of vertebrae and visceral skeleton. P. argenteus and P. echinogaster are distinguished by the morphology of jaw, fin and isthmus. In P. argenteus, wavy ridges extends over the upper part of pectoral fin and gill membrane is broadly united to isthmus, while in P. echinogaster the ridges are limited to the base of pectoral fin and gill membrane reaching isthmus. These Pampus spp. are easily distinguished based on internal features, such as number of vertebrae, gill raker, pyloric caeca, epipleural bone, esophageal sat and length of intestine.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.423-435
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• 1984

The reproductive cycle of the small filefish, Rudarius ercodes was investigated based on the annual variations of gonadosomatic index(GSI) and hepatosomatic index(HSI) by electronic and photic microscophy. The specimens used were collected at the coastal area of Benden island, Sizuokagen, Japan, from September 1982 to August 1983. GSI began to increase from March, starting season of longer daylength and higher water temperature, and reached the maximum value between June and August. It began to decrease from September with the lowest value appearing between November and February without any evident variation. The annual variations of HSI were not distinct in male filefish and were negatively related to GSI in female : HSI decreased in the summer season when the ovary was getting mature and reached the maximum in the winter season when the ovary was getting retrogressive. The ovary consisted of a pair of saccular structure with numerous ovarian sacs branched toward the median cavity. Oogonia divided and proliferated along the germinal epithelium of the ovarian sac. Young oocytes with basophile cytoplasm showed several scattering nucleoli along the nuclear membrane. when the oocytes growing to about 300 ${\mu}m$, nuclear membrane to disappear with nucleus migrating toward the animal pole. The regions of protoplasm were extremely confined within the animal hemisphere in which most of cytoplasms were filled with yolk materials and oil drops. After ovulation, residual follicles and growing oocytes remaining in the ovarian sacs degenerated. But perinucleatic young oocytes without follicles formed were not degenerated, and growing continuously still in the next year. Mitochondria and endoplasmic reticula in the cytoplasm remarkably increased with oocytes maturing and yolk accumulating. Those were considered to be functionally related to the yolk accumulation. Five or six layers of possible vitellogenin, oval-shaped disc structures with high electron density, appeared in the apex of follicular processes stretching to the microvilli pits of mature oocytes. Testis consisting of a pair of lobular structures in the right and left were united in the posterior seminal vesicle, Cortex of testis was composed of several seminiferous tubules, and medulla consisting of many sperm ducts connected with tubules. Steroid hormone-secreting cells with numerous endoplasmic reticula and large mitochondria of well developed cristae were recognized in the interstitial cells of the growing testis. Axial filament of spermatozoon invaginated deeply in the central cavity of the nucleus and the head formed U-shape with acrosome severely lacking, mitochondria formed large globular paranuclei at the posterior head, and microtubular axoneme of the tail represented 9+9+2 type. The annual reproductive cycles could be divided into five successive stages : growth(March to July), maturation(May to September), Spawning(mid May to early October) and resting stages(October to February). The spawning peak occurred from June to August.